The Greenlink Connector, which costs $580 million (GBP 430 million) and connects Ireland to Wales via an undersea power cable, was rerouted after scores of Harry Potter fans complained that it would go through the grave of the beloved house elf “Dobby.” According to The Guardian, project manager Simon Ludlam pointed out in a BBC interview that the cable would transition underwater at Freshwater West. Unfortunately, Ludlam was unaware that this was the filming location for the site where the Harry Potter character was buried in the movie franchise. When the BBC aired the clip, the project began receiving hundreds of calls about the site.
Ludlam recounted to The Guardian a discussion with a colleague when they told him, “Apparently, we’re going to go straight through Dobby’s grave.” He answered, “Dobby? Who’s Dobby? I don’t know Dobby.” It seemed that the project manager was in disbelief when it was finally explained that Dobby is the freed house elf who was killed in the process of rescuing Harry Potter and his friends in the last book. “He is a fictitious character in a fictitious book — the whole thing is fictitious. What are you talking about?” Ludlam said, after which his colleague replied, “No, it’s very, very serious.” In the end, the company working on the project acquiesced to the demands and concerns of the Harry Potter fans and rerouted it. “A lot of people were very happy about that, and the project is now going [ahead], and Dobby’s happy,” the project manager said.
The Shell Cottage, where Dobby is buried, is on the outskirts of the fictional town of Tinworth, in Cornwall, but the original film series shot the scene in Freshwater West. Many Harry Potter fans leave stones marked with “Here lies Dobby, a free elf,” as a nod to the epitaph that the titular hero left on his grave. The National Trust, which owns the land, has previously warned pilgrims not to do so, as the area is ecologically sensitive, but it seems that people still do so. The fans’ resistance to having Dobby’s “grave” desecrated seemingly prevented the undersea cable from going through the area. It was instead rerouted in an area that was close to some Bronze Age remains and urns, which, ironically, are associated with human burial.
Undersea cables are crucial infrastructure connecting distant locations for sending information, power, and other crucial resources. Many of them face increasing threats, especially in areas that face geopolitical pressure, like Taiwan and the Baltic Sea, which is why companies are creating technologies to help detect intentional tampering. However, it seems that the one thing that the planners of this particular project did not take into account is the passion of Harry Potter fans.
As Elon Musk, Peter Thiel and their peers have grown richer and more influential, Gil Durán argues they have all but abandoned democracy – and found the perfect government to enable them
In April, Gil Durán was permanently banned from Elon Musk’s X for posting just two words. Durán was responding to a post from the tech company Palantir outlining its 22‑point “technological manifesto”, which praised American “hard power”, western culture and AI weapons, denounced inclusivity and called for compulsory national service. Durán responded: “TLDR: Fascism” (TLDR is short for “too long, didn’t read”).
Durán didn’t break any of X’s written rules, he points out over a video call from San Francisco – so much for Musk’s “free-speech absolutism”. His ban might just have had something to do with his preceding tweet, showing the cover of his new book, The Nerd Reich: Silicon Valley Fascism and the War on Democracy. The book’s central argument is that big tech is no longer our friend, as many of its billionaire owners have seized economic and political control and are steering the fate of the planet towards their own bizarre, apocalyptic visions.
Ruling comes as part of second phase of landmark trial that found social media company enabled harm against users
A New Mexico court has ordered Meta, the parent company of Facebook, to pay $567m into a fund aimed at redressing adverse mental health impacts from the social media giant’s platforms.
The Thursday ruling comes as a part of the second phase of a landmark trial the social media giant lost in March. At the time, a jury found that the company knowingly harmed children’s mental health and concealed what it knew about child sexual exploitation on its platforms, and imposed the maximum penalty: a $375m fine.
The way Apple combines work and personal iCloud accounts left some employees able to access confidential documents after departing the company, reports The Information. The site spoke to more than half a dozen former Apple employees who were unknowingly left with access to sensitive content.
[…]
Apple told The Information that the OpenAI lawsuit is unrelated to any files left available on iCloud and that it does not pursue legal claims against former employees who accidentally have Apple documents in their personal iCloud accounts.
[…]
In a now-settled legal dispute, chip company Rivos claimed Apple intentionally lets former employees retain access to files “as part of a planned effort to generate a pretextual basis to sue the employees and their new employer for ‘stealing’ Apple material.” In the Rivos case, an employee was targeted for keeping work files in his personal iCloud account.
The documents included confidential material such as plans for product launch events. The former employees said they made no effort to retain access and unexpectedly found the files mixed with their personal iCloud data.
The problem reportedly grew from Apple’s practice of encouraging employees to connect their personal Apple IDs to company-funded iCloud storage.
[…]
Apple also relied heavily on iMessage for workplace conversations and file sharing before rolling out Slack around 2019. Former employees could retain old iMessage conversations and attachments, while Apple could terminate their Slack access when they left.
If you use your personal Apple ID, you get a magic “Apple Work” folder in iCloud Drive. When you leave Apple, that “Apple Work” folder disappears. But any other files or folders that were shared with you that were outside that magic folder are still in your iCloud Drive, because it’s still your personal iCloud account.
[…]
You still have the same Apple ID account, even though you no longer have an employee @apple.com email account. Overall, this is a humane way of dealing with digital identity. Your Apple ID account is you, the person, not “example@icloud.com”, one specific unique email address. And you, the person, may well have multiple email addresses — all of which can be associated with your one Apple ID account. That makes Apple IDs more nuanced and complicated than a simple mapping of one email address = one account. And it obviously makes access restrictions more complicated.
Yesterday, OpenAI released messages to show that Apple employees (with permission) retained access to the departing employee’s personal iCloud account so that they could access work files that were stored there. It’s just a mess that both the software and corporate policy encourage mixing everything in one account.
The company said his performance was the reason, according to a lawsuit Boardman filed in San Francisco Superior Court. Boardman says that explanation was a pretext. His version of the story begins three years earlier, inside Apple’s technical relationship with the largest wireless carriers in the United States, with a category of data capable of identifying nearly every phone on the network.
[…]
Apple considered serial numbers and IMEIs personally identifiable information under its internal policies, Boardman alleges. Representatives working with carriers other than AT&T required the carrier to obtain a customer release before Apple supplied the data. The Apple representative assigned to AT&T did not enforce that requirement, according to the complaint. Boardman says the identifiers were then transmitted through “unsecured email communications.”
He reported the practice to his manager and sought guidance from Apple’s legal department. He alleges that the company never gave him a written response.
I don’t think he has much of a legal case. Apple was probably within its rights to fire him if what he refused to do was against company policy but not illegal. It doesn’t sound like Apple is disputing that, at least not yet.
However, I think this is interesting because:
This seems to be another case, like yesterday’s story, where the interests of the customer and the carrier are at odds, and Apple leans towards the latter.
It shows that a policy is no guarantee, because it depends on humans choosing to follow it. There are other cases where Apple has been able to engineer privacy into the system. But some data is not end-to-end encrypted, so consent is a formal but a not technical requirement.
A developer has created a proof-of-concept data transfer system that shuns any dedicated app requirement and neatly sidesteps mandatory networking, pairing, or giving permissions beyond camera access. Instead, the method transmits information between devices by streaming data via rapidly updating QR codes at up to 60 FPS via the browser your smartphone already has. The test info shared by developer bashalarmistalt on GitHub backs claims that these transfers can run at up to 190 KB/s. This low-friction two-device screen-to-camera data transmission technique is dubbed Decimen Optical Transfer: fountain-coded QR file transfer.
The GitHub project is linked to by Redditor Alstroph, who seems to be the same person. We’ve chosen to embed the Reddit post about the Decimen Optical Transfer solution above, as it includes an illustrative video of a QR code-driven data transfer.
Bashalarmistalt/Alstroph says they used Claude Code to build this cached web app, which simply runs on both smartphones within the browser, with camera permissions given. They explain that they came up with the idea behind Decimen Optical Transfer to create “a phone-to-phone file transfer option without requiring the phones to be on the same network.” After a modicum of chin stroking, they settled upon the possibility of using “rapidly flashing QR codes” to brew up this proof-of-concept.
Far more detailed information about the project is available in the GitHub repository, linked above. There we also read that the use of ‘fountain codes’ was instrumental to the technique, ensuring missed frames and retransmission quirks don’t hinder the data transfer process. Also, it is explained that every streamed QR code frame is self-describing, as a “20-byte header carries the session ID, sequence number, block count/size, file length, and a hash.”
Hints are provided for tuning Decimen Optical Transfer performance with the PoC solution. The dev used an iPhone and the Apple ProMotion camera with stacked codes; they achieved ~128 KB/s handheld data transfers. The data rate could climb to ~186 KB/s speeds if both the sender and receiver devices were positioned absolutely stationary.
The Decimen Optical Transfer software is distributed under the generous MIT license. Bashalarmistalt is aware that there have been several prior projects but asserts the concept behind their Claude Code-aided solution was arrived at independently. We’ve also covered QR code-based data storage tech numerous times. For example, Cerabyte famously uses microscopic QR codes for its ultra-long-life ceramic storage.
Microsoft cloud and Azure services hosted on the West Coast of the US went down for hours on Thursday when network connectivity failed. Although services running entirely within Microsoft’s West US cloud region were unaffected, any traffic entering or leaving the facilities was affected.
Microsoft has now published a Preliminary Post Incident Review (PIR) of the incident, reporting that connectivity was lost for five hours between 14.44 UTC (7.44 a.m. Pacific Time) and 19.41 UTC on July 23. The problem was caused when a set of IP routes was removed in error while isolating a device for routine maintenance.
Before starting the maintenance work, Microsoft checked that at least one of the two redundant paths to the facility remained operational. When it came to starting the work, however, automated systems included some additional devices in the perimeter to be isolated, and removing some IP routes that had not been included in the initial assessment.
Customers discovered the problems very quickly, and engineers identified the issue within the first hour and started to reconnect services. Microsoft said the disruption had been caused by some “recent fiber maintenance activity”.
To minimize the risk of disruption from such errors in the future, Microsoft advised organizations handling mission-critical data to consider a multi-region approach.
AMD executives took to the stage at its Advancing AI 2026 event in San Francisco today to detail the company’s next generation of AI infrastructure solutions, from Instinct MI455X AI accelerator GPUs and 6th Gen EPYC “Venice” CPUs, to Pensando networking, ROCm.AI software and its Helios rack-scale platform that ties it all together.
AMD has been working towards rack-scale AI system solutions for years. Its ZT Systems acquisition last year added valuable engineering talent and intellectual property that is now finally bearing the real fruits. Its Helios AI platform is a major platform evolution for AMD, with shipments scheduled to begin in the second half of this year (which is here and now).
The announcements at Advancing AI show how the company has engineered its AI platform solutions for large reasoning models, sustained inference and agentic workflows. These workloads pressure memory capacity, data movement, networking and CPU orchestration. AMD’s approach is to keep as much data close to the compute engines as possible and move it more efficiently throughout the system, but there’s deeper nuance here that’s obvious versus AMD’s chief rival, NVIDIA.
AMD’s MI455X targets the AI memory wall
The Instinct MI455X GPU is the compute engine that fuels the Helios rack, and the first GPU based on AMD’s new CDNA 5 architecture. Built with a modular mix of 2nm and 3nm chiplets, it carries 432GB of HBM4 and 23.3TB/s of peak memory bandwidth.
Compared to AMD’s current MI355X, the MI455X offers 1.5 times the memory capacity, up to 2.9 times the peak memory bandwidth and up to four times the peak matrix performance with MXFP4 and MXFP8 data types, which are lower-precision numerical formats designed to accelerate AI processing while reducing memory demands. With MXFP6 (6-bit floating point), performance is rated at up to twice that of MI355X.
AMD also shared some actual, measured internal results using production silicon. The company claims MI455X delivers 3.8 times higher FP8 decode performance, 3.5 times more measured FP4 compute performance and between 2.5 and 3.5 times more networking bandwidth than MI355X, depending on the transfer path tested. Those figures provide more context than just numerical specifications, though they remain AMD-provided comparisons that will need independent validation.
AMD
The architectural choices behind the numbers are important. Reasoning models and long context windows require sizeable KV caches for maintaining AI attention states, while mixture-of-experts models frequently move large amounts of data across accelerators. MI455X should let more model data, activation states and cache remain local. New dedicated IP in hardware can transfer data while the GPU continues processing, and expanded cache and multicast capabilities are designed to reduce redundant data movement to further improve efficiency.
The aforementioned lower-precision formats can also raise throughput and reduce memory use, but model developers still have to determine where they can be applied without unacceptable accuracy loss.
AMD’s Helios rack takes aim at Vera Rubin
Dave Altavilla
Helios is AMD’s primary rack-scale competitor to NVIDIA’s Vera Rubin platform. Each liquid-cooled rack combines 72 MI455X GPUs, 18 single-socket Venice host CPUs and Pensando networking technologies.
In its most complete, premium configuration, AMD rates Helios for 2.9 exaflops of low-precision AI compute, with 31TB of aggregate HBM4 capacity, 1.7PB/s of memory bandwidth, 260TB/s of bidirectional scale-up bandwidth and 43TB/s of scale-out bandwidth.
These are formidable figures, but they are technical specifications rather than actual application benchmarks. The more consequential development is AMD’s move from collections of eight-GPU servers to a 72-GPU shared-memory domain. Models too large for one node can operate across the rack without treating every exchange as a scale-out networking transaction, which benefits large-model inference as well as training.
AMD uses UALink over Ethernet, or UALoE, for an open standard scale-up fabric. Each MI455X provides 3.6TB/s of bidirectional scale-up bandwidth, while the complete rack delivers all-to-all connectivity through a single switch layer. AMD also claims six times more scale-out bandwidth per GPU than MI355X when MI455X is configured with three Pensando Vulcano 800 AI NICs.
While open standards give cloud providers more control over suppliers and system design, AMD and its partners now have to prove those components can deliver the predictable performance, reliability and deployment experience customers expect from a tightly controlled, more vertically integrated platform.
Finally, AMD designed Helios with automatic rerouting around failed links, virtual rack partitions, tray-level serviceability and rack-wide power, cooling and health monitoring. Major hyperscalers and potentially large-scale enterprise customers will likely key in on these capabilities, which can affect the availability, total cost and consistency of the AI services they consume.
Kind of like cowbell, AMD Venice gives agentic AI more CPU
AMD
AMD’s agentic CPU messaging regarding its upcoming Venice-based EPYC processors is mostly marketing speak, but the underlying requirement is very real. An AI agent can invoke retrieval, databases, security checks, code execution and other tools before a GPU generates a response. Running many agents concurrently increases the amount of conventional compute requirements surrounding the accelerators.
Venice scales to 256 Zen 6 cores with support for 512 threads, 16 memory channels, up to 1GB of L3 cache per socket, along with PCIe 6.0 and CXL 3.1 connectivity. AMD is also offering several Venice configurations for other applications, including general-purpose servers, high-frequency workloads, GPU hosts and high-density CPU sandbox systems used to execute agent tools.
Treating the CPU solely as a GPU host understates its role. Gateways, tokenization, vector search, databases and short-lived code execution stress different mixes of per-core performance, thread count, memory bandwidth and I/O. Specifically, AMD’s internal testing shows Venice significantly outperforming its current EPYC 9965 Turin CPU across five parts of the agentic AI pipeline, including gateway processing, context assembly, vector search, enterprise applications and short-lived tool execution. Individual gains vary by workload, but AMD details the overall generational improvement at up to a 1.7 times lift. As with the MI455X figures though, these comparisons come from AMD and will require independent validation.
Pensando networking and ROCm software advance
Keeping GPUs fed with data and coordinating traffic across racks directly affects utilization and operating costs. In fact, GPU utilization is a pretty sad state of affairs currently for some of the major frontier model providers.
As such, Pensando networking has become central to AMD’s roadmap. Helios can connect each MI455X to as many as three 800Gbps Vulcano AI NICs, while Salina DPUs handle front-end networking and infrastructure services.
On the software side, which is an equally critical component, AMD also introduced ROCm.AI, an AI-assisted development layer due to arrive in August. It includes reusable skills for coding agents, simplified management and Hyperloom, which can profile workloads, tune serving configurations, modify kernels and validate results.
These tools address two persistent AMD challenges: developer efficiency and ease of use, and software tuning. Automated optimization still has to produce repeatable gains without creating hard-to-maintain code, however. And while ROCm has progressed significantly over the last few years, NVIDIA’s CUDA retains an advantage in maturity, tooling and developer familiarity.
AMD now has commitments that give its MI450 generation and Helios considerably more weight. Meta and OpenAI have announced multi-generation agreements composed of up to 6GW of AMD compute capacity, with initial 1GW deployments planned for the second half of 2026.
Oracle plans a 50,000-GPU public cloud cluster beginning in the third quarter, while Microsoft will deploy Helios for Azure AI inference. Finally, just before the AMD event, Anthropic announced a strategic partnership for up to 2 Gigawatts of AMD-fueled AI compute, with its first gigawatt expected online in the first half of 2027.
Commitments of this scale reflect confidence in more than just MI455X performance. These customers are evaluating the complete architecture, including Venice CPUs, Pensando networking, ROCm software, rack integration, serviceability and AMD’s ability to deliver and execute across multiple product generations.
There is some financial alignment behind the agreements as well. AMD issued OpenAI performance-based warrants and committed to investing up to $5 billion in Anthropic. That context matters when evaluating these deals as market validation, but these planned deployments are substantial nonetheless and put Helios on a much stronger foundation as it begins shipping.
AMD expands its robotics and embedded foundation
AMD also expanded its physical AI portfolio, building on credible traction from its Xilinx-derived Kria adaptive system-on-modules and embedded technologies that are already powering robotics, machine vision and industrial automation applications.
The new Ryzen AI Embedded X100 combines up to 16 Zen 5 CPU cores, integrated Radeon graphics, a second-generation NPU and as much as 128GB of unified LPDDR5X memory shared across its compute engines. To me this looks a lot like a repackaging and optimization of the company’s Strix Halo platform, but with specific optimizations for the embedded space. Regardless, AMD is pairing X100 with the Kria AI Robotics Developer Platform, which includes a System Module or SOM, and a new Robotics Partner Network spanning hardware, software and platform providers.
Samples began shipping in June, with full production expected in the fourth quarter. This broader objective is to give developers a path across AMD x86 CPUs, GPUs, NPUs and FPGAs for real-time autonomous systems, rather than requiring them to assemble those hardware engines and software components independently.
Execution for AMD is now the test
AMD has assembled a credible platform for the burgeoning agentic AI market that’s blowing up currently with no signs of stopping. MI455X addresses memory and data movement, Venice handles dense agentic CPU workloads, Pensando networking connects global system resources, and ROCm.AI addresses software complexity. Finally, Helios assembles these components into a true competitive threat for NVIDIA’s latest Vera Rubin platform.
AMD’s open architecture may appeal to customers seeking supplier choice, but openness must also translate into reliable deployments, competitive total cost and software that does not require a significant rip-up. NVIDIA enters this cycle with a stronger ecosystem and far more rack-scale deployment experience. The true test will be how easily and reliably customers can integrate, operate and maintain these AMD solutions at scale.
As it stands, AMD now has major customers and a clearly defined architecture with systems engineering expertise behind it. Delivering Helios on schedule and showing that its performance claims translate into a real production workload throughput advantage and total cost of ownership gains will determine how much the competitive gap narrows. And of course, this is in a market that is clamoring for ever-more compute resources with a seemingly insatiable demand for AI services and capacity. That’s an environment for big iron success. Now AMD just has to deliver optimized, turnkey AI platforms. This is far easier said than done, but time will soon tell as deployments take shape this year.
This article is published as part of the Foundry Expert Contributor Network. Want to join?
The open-plan floors make it hard to concentrate. The building is so large that getting from one meeting to the next eats real time out of the day. It’s common for people to run meetings with colleagues over Webex — colleagues on the same campus, sometimes no more than two hundred yards away.
Ironically, Apple Park replaced a campus that did far better on the same measure without ever trying to. Infinite Loop produced far more of the accidental, cross-team contact Apple Park was explicitly built to create. Working out why starts with what Infinite Loop got right by accident. It continues with what the research on office proximity says about why that kind of thing happens at all. And it ends with what Apple Park could become instead — including a version of the fix Apple already trusts enough to run for a hundred people a year.
[…]
There’s no obvious focal point for the whole site — most sections have their own sitting area and their own coffee bar, but nothing plays the role Caffè Macs and the IL1 coffee bar played together at Infinite Loop. Caffè Macs at Apple Park seats a thousand people and feels built for throughput, not conversation. Everything is organised per-segment rather than around a shared centre, which is convenient for the people in that segment and useless for the discovery-by-accident that made the old campus work.
[…]
By multiple accounts from people who were there during design and construction, the site was flagged as under-provisioned for meetings and conferences before it even opened.
Apple Park is a beautiful structure, but is not terribly conducive to focused or collaborative work. Even as an occasional visitor I found it overwhelming. Employees sit shoulder to shoulder, voices bounce off and bleed through glass walls, and privacy is a virtual impossibility. My friends and colleagues who worked there regularly found it difficult to be productive.
I worked in Infinite Loop (Building 3, 2nd floor) for thirteen years (right below Developer Publications, where Malcolm spent a good portion of his Apple career). I loved IL because its design made serendipitous encounters easy. Whether it was sitting outside Caffè Macs or in the IL 1 Atrium, I would inevitably bump into someone and have a conversation that furthered an in-flight project, sparked something new, or simply reinforced the social ties that bind colleagues.
It helped that at that time, Apple had perhaps 10,000 employees, most of whom were in or near IL. After iPhone came about and IL started getting locked down, much of the natural collaboration dissipated, disappearing behind badged doors and disclosures.
IL provided a place to focus on your work[1], as well as seating spaces that are out of the flow of traffic where you can have an informal meeting[2]. At AP, every collaborative space is effectively in the middle of a hallway. That turns out to be enormously distracting, both to you and to those people trying to work in the glass bullpen right next to it.
[1] before all cubicles and offices became multi-person shared spaces
[2] before all those spaces were filled in with more offices
“The IL1 atrium really was the crossroads of the company in those days” I really don’t think that this is true literally by any means. Assuming “those days” overlap with the time I’ve been there (pre Park). The XFs in IL have been extremely scarce.
IL was way too small and overloaded, I’d actually say it was very similar to Apple Park. No one really wanted to work there in those tiny offices with multiple people 🤷♀️
I loved the IL1 atrium. I’d sit there and hope that someone like MMalc would wander by, and they often did. It was a real destination for field people who didn’t get to visit the mothership very often. I miss that. AP had nothing like it.
I think of my days in college—most dorms residence halls were not air conditioned, so at the end of August, you had to open your window (often to place a box fan) and door to create some airflow. People walking through the building would meet by chance. Newer buildings tended to be less lively and more like a hotel—all the doors closed and rarely much activity. Through renovations, most of the buildings have had air conditioning added, dropping those interactions over the years.
As you may know, the Lumon Industries building that Mark, Helly, Irving, and Dylan work in is a former Bell Labs facility in Holmdel, New Jersey. I first learned about the building several years ago, when I read Jon Gertner’s excellent history of The Labs, The Idea Factory. It’s a distinctive place designed by Eero Saarinen in the early 60s.
Bell Labs was known for the fruitful collaboration of its researchers, often started through chance meetings in the hallways of other Bell Labs facilities. The new Holmdel building was supposed to further that sort of teamwork, but things didn’t work out as planned.
I worked in IL1 for over a decade. The day I saw the open-plan spaceship, I knew I would never set foot inside. There are more rewarding ways to work in a barn.
Tired of clunky email triage on your iPhone? Avec’s swipe-based interface lets you quickly sort important messages from noise, using AI to prioritize what matters. It’s Gmail-only and iPhone-only for now, but IMAP support is promised and a desktop version is coming.
I’ve had a Brother printer & liked it very much, but can’t get updated software compatible w my Mac mini OS 26.5. Can anyone recommend a model they really liked that didn’t have confusing set-up of air-print?
Apple’s built-in screen sharing support for Mac-to-Mac connections has always been a help for those of us with remote setups: headless Macs acting as servers, an office and home Mac, or the laziness of having Macs in different parts of your house you want to access without standing up.1
Under the hood, Apple relies on VNC (Virtual Network Computing), a fairly ancient standard at this point in time, and you probably get the sense of its creaking joints if you use the Screen Sharing app regularly.2 But it’s possible you didn’t know that, starting in Sonoma, Apple added a “super excellent” mode to Screen Sharing as an option when you connect two Macs with M-series chips. Called High Performance, it can deliver on its name.
Let’s shift into overdrive
When you initiate a connection, Screen Sharing asks you to pick between Standard and High Performance modes.
When you connect to another Mac using Screen Sharing, you’re given a choice of which mode to use. Let’s walk through the connection steps:
Either launch the Screen Sharing app and double-click the Mac’s name in a list, or, in the Finder, Control-click/right-click the Mac’s name and choose Screen Sharing. (There are still more ways to start, too.)
From the Select Screen Sharing Type options, you can select Standard, which is VNC-based, or High Performance, which adds Apple’s secret sauce on top.
Click Continue.
Enter your credentials.
The screen appears, and you may need to enter your macOS account password on the remote Mac to unlock it.
In that pathway, if you choose High Performance, you’re presented with different options. You can also click the info (i) button to the right of an existing connection in the Connections window in Screen Sharing, and choose High Performance from the Screen Sharing Type pop-up menu to save that option for the next connection.
A saved connection’s settings let you change the sharing type, display configuration, and port after the fact.
With a Standard connection, you get a pixel-for-pixel remote view of the other Mac’s display or displays. It’s just like you’re sitting in front of it. In fact, if you use the same account as the currently logged-in user, the remote Mac shows what you’re doing to anyone who looks at it. (You can log in as another user, and a session starts in the background that doesn’t appear on the remote display screen.)
High Performance takes a different approach. You can opt to create one or two virtual displays on the remote Mac, each with independent resolution, high-dynamic-range (HDR) support, and other features. It’s like being a remote user of the computer rather than sharing. (This mode doesn’t change the remote display resolution or other settings.)
With a High Performance connection between Apple silicon Macs, you gain these advantages:
You can choose one or two virtual displays, regardless of the number of displays connected to the shared computer.
The Dynamic Resolution option lets you resize a virtual display to the native resolution of your local screen, up to 4K (3840×2160 pixels) or, with HiDPI, up to 1920×1080. You can click the Dynamic button on the Screen Sharing toolbar or choose View: Dynamic Resolution during a live session.
Stereo audio passes over the connection, as does improved video. The connection supports HDR (for richer low-light and shadow tones), 4:4:4 chroma subsampling (uncompressed color data for improved fidelity), and high frame rates of 30 or 60 frames per second (for more stable video streaming, such as when watching a video or using video-editing software).
The downside of High Performance is that it imposes severe requirements for it to work well. You need 75 Mbps per 4K display and low network latency, which requires fast Wi-Fi with a gigabit-or-faster mesh or wired backbone if there are multiple network routers or base stations. However, that requirement also means that when you’re using High Performance, it feels very much like sitting in front of the other display rather than viewing it remotely.
The Screen Sharing toolbar with High Performance mode enabled offers controls unavailable in a Standard session; some options remain dimmed depending on the remote Mac’s capabilities.
If you want the depth of HDR Video, you have to enable it on the remote Mac via System Settings: Displays. The option for HDR Video appears in a Preset pop-up menu, but, of course, only if the display supports the right HDR signal. HDR can be enabled or disabled from the View menu and Screen Sharing toolbar, if it’s available.
Because the remote display is blacked out when using High Performance (even when connecting as the currently logged-in user), this can be seen as a privacy advantage if you have concerns about anyone else viewing the remote Mac’s screen. However, High Performance mode’s utility really lies in treating Screen Sharing like a high-speed display tunnel instead of a jerky remote view.
For further reading
If you’re looking for more detailed information about High Performance mode or any aspect of Mac-based file and screen sharing, you might consult my book, Take Control of Apple Screen and File Sharing.
[Got a question for the column? You can email glenn@sixcolors.com or use/glennin our subscriber-only Discord community.]
I don’t have a couch Mac and a kitchen Mac and a bedroom Mac and a… you get it. But I do have a downstairs office Mac and a laptop. ↩
Screen Sharing is found in /System/Applications/Utilities, just an oddity of how Apple locates certain apps on the immutable System volume. ↩
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