Zed for Windows: What's Taking So Long?

https://zed.dev/blog/windows-progress-report

by janjones • 11 months ago

88 79 11 months ago

As a Windows dev...

but we got reports from users that Zed didn't run on their machines due to the Vulkan dependency

This single sentence is abstracting a lot of detail. Vulkan runs on Windows, and quite well. Looking at the bug reports, especially the last one[1]...

Rejected for device extension "VK_KHR_dynamic_rendering" not supported

Aha, ambitious devs >:) The dynamic rendering extension is pretty new, released with Vulkan 1.3. I suspect targeting Vulkan 1.1 or 1.2 might've been a little more straightforward than... rewriting everything to target DX11. Large games with custom engines (RDR2, Doom, Doom Eternal) were shipped before this was main-lined into Vulkan.

But thinking about it a little more, I suspect switching out the back-end to a dynamic rendering-esque one (which is why D3D11 rather than D3D12) was easier than reverting their Rust code to pre-dynamic rendering Vulkan CPU calls; the Rust code changes are comparatively light and the biggest change is the shader.

That being said, it's a bit annoying to manually write render-passes and subpasses, but it's not the worst thing, and more importantly extremely high performance is less critical here, as Zed is rendering text, not shading billions of triangles. The singular shader is also not necessarily the most complex[2]; a lot of it is window-clipping which Windows does for free.

we had two implementations of our GPU shaders: one MSL implementation for macOS, and one WGSL implementation for Vulkan. To use DirectX 11, we had to create a third implementation in HLSL.

I wonder why HLSL wasn't adopted from the outset, given roughly 99.999% of shaders—which are mostly shipped with video games, which mostly target Windows—are written in HLSL, and then use dxc to target SPIR-V? HLSL is widely considered the best-specified, most feature-complete, and most documented shader language. I'm writing a Vulkan engine on Windows and Linux, and I only use HLSL. Additionally Vulkan runs on macOS with MoltenVK (and now 'KosmicKrisp'), but I suppose the Zed spirit is 'platform-native and nothing else'.

symbolicating stack traces requires a .pdb file that is too large to ship to users as part of the installer.

Perhaps publishing a symbol server[3] is a good idea here, rather than users shipping dump files which may contain personally-identifiable information; users can then use WinDbg or Visual Studio to debug the release-mode Zed at their leisure.

[1] https://github.com/zed-industries/zed/issues/35205

[2] https://github.com/zed-industries/zed/blob/c995dd2016a3d9f8b...

[3] https://randomascii.wordpress.com/2020/03/14/creating-a-publ...

andrewmcwatters• 11 months ago

Yeah, I maintain a Vulkan backend, and this immediately triggered my internal "what?" alarm.

Modern Direct3D is almost indistinguishable from Vulkan, on the other hand. So it shouldn't be difficult for them to add.

I also agree with your HLSL comment. It sounds like these guys don’t have much prior graphics or game development experience.

delta_p_delta_x10• 11 months ago

I'd been thinking about it, and I added another paragraph above. I get a feeling they've been targeting Vulkan 1.3 with dynamic rendering from the beginning, so porting to D3D12 would be roughly as complex as rewriting to target older Vulkan.

maxbrunsfeld• 11 months ago

The Zed spirit is definitely to prefer a platform native solution.

You're right that we may be able to get rid of our WGSL implementation, and instead use the HLSL one via SPIR-V. But also, at some point we plan to port Zed to run in a web browser, and will likely build on WebGPU, where WGSL is the native shading language. Honestly, we don't change our graphics primitives that frequently, so the cost of having the three implementations going forward isn't that terrible. We definitely would not use MoltenVK on macOS, vs just using Metal directly.

Good point that we should publish a symbol server.

jamienicol• 11 months ago

Did you consider using wgpu instead of writing a new dx11 renderer? It has metal, vulkan and dx12 backends so could have been used for a single renderer for macOS windows and Linux. (And webgpu in the future)

bsder• 11 months ago

But also, at some point we plan to port Zed to run in a web browser, and will likely build on WebGPU, where WGSL is the native shading language.

Except that everything has effectively converged to HLSL (via Slang which is effectively HLSL++) and SPIR-V (coming via Shader 7).

So, your pipelines, shader language, and IR code would all look mostly the same between Windows and Linux if you threw in with DX12 (which looks much more like Vulkan) rather than DX11. And you'd get the ability to multi-thread through the GPU subsystem via DX12/Vulkan.

And, to be fair, we've seen that MoltenVK gets you about 80-90% of native Metal performance on macOS, so you wouldn't have to maintain a Metal backend, anymore.

And you'd gain the ability to use all the standard GPU debugging tools from Microsoft, nVidia, and AMD rather than just RenderDoc.

You'd abandon this all for some mythical future compatibility with WebGPU--which has deployment counts you can measure with a thimble?

TiredOfLife• 11 months ago

Zed spirit is Mac first and only.

mrpippy• 11 months ago

Vulkan runs on Windows, and quite well.

Not everywhere. See the middle bug report, "Zed does not work in Remote Desktop session on windows" (https://github.com/zed-industries/zed/issues/26692).

Most Remote Desktop/Terminal Services environments won't have any Vulkan devices available, unless you ship your own software rendererer (like SwiftShader).

Also, NVIDIA only supports Vulkan on Kepler (GTX 600 series), AMD on GCN 1.0 (Radeon HD 7000 series), and most importantly, Intel on Skylake (6000 series). Especially on the Intel side, there are plenty of old but still-supported Windows 10 machines that lack Vulkan support. For many applications that's ok, but IMO not for a text editor.

shortrounddev22• 11 months ago

I wonder why HLSL wasn't adopted from the outset

I suspect because a huge amount of software engineers develop on Macbooks and consider Linux second and Windows third. Culturally, I think there's a difference in tooling between Graphics developers (who would go straight for HLSL, cross-platform Vulkan, or even SDL3) and mac users (who reach for Apple tools first)

RattlesnakeJake• 11 months ago

Entirely unrelated, but the sections, toolbars, and controls in that RenderDoc app are so cleanly separated compared to modern dev tools. I wish more apps still looked like this.

jbverschoor• 11 months ago

I have my macOS set up that all buttons have borders etc

If I switch no vanilla macOS, it’s basically unusable

Clean, but unusable

mxhwll• 11 months ago

This is why you don’t make your own cross platform toolkit.

andsoitis• 11 months ago

while I would agree in general, there could theoretically be SOME applications where the range of UI controls (and systems) is small enough where it could pay off. But things tend to expand in surface area...

So with that, this presents a HUGE opportunity for someone to build something akin to Zed, but not with the baggage that their technical strategy brings.

cosmic_cheese• 11 months ago

So with that, this presents a HUGE opportunity for someone to build something akin to Zed, but not with the baggage that their technical strategy brings.

Not sure it’s so clean-cut. More than avoiding baggage, you’re just shifting it elsewhere. The question is if you want to own (and can handle) the baggage and benefit from the control that brings.

WD-423• 11 months ago

You'd rather see another crappy, slow editor packaging an entire browser? Because that seems like what people are using for "cross platform toolkits" these days. I'm glad Zed is being ambitious, it's truly a joy to use because it feels native. And to be honest, it's Windows, who cares. If you are a developer you should have switched to Linux years ago anyway.

steve_adams_864• 11 months ago

No, there are good reasons developers are on Windows. Industrial and embedded systems are very often Windows-based, for better or worse. Heaps of games are developed on Windows. Windows-based software itself is developed on Windows.

pjmlp6• 11 months ago

I use computers since 1986, UNIX variants since 1992, and yet Windows is where I spend most of my time.

I find hilarious this FOSS concept that developers only use Linux, I wonder who writes software for all other operating systems in the world.

perching_aix2• 11 months ago

If you are a developer you should have switched to Linux years ago anyway.

This is so often repeated, but I genuinely don't understand why. Could you try selling me on it? I ended up going the sysadmin/devops route instead after college, but the more I learn about Linux, the less I understand why anyone would choose it for personal, active manual use.

I can understand server deployments, it works well enough. It's available at no cost, Windows Server is way out in the far other end in terms of current desired behavior, and whatever pains it has you get paid to make up for. None of which applies on a personal device level.

The most common selling points I see are more performance and less "spying". I find neither of these very persuasive, and I'm not interested in ideological rationales either (supporting free software). If you have anything else, I'm all ears.

vovavili• 11 months ago

If you are a developer you should have switched to Linux years ago anyway.

These days, WSL2 effectively eliminates a need for that for most developers.

wolvesechoes3• 11 months ago

You'd rather see another crappy, slow editor packaging an entire browser?

Windows still offers other options, even if MS itself tend to ignore them.

If you are a developer you should have switched to Linux years ago anyway.

Developers is much broader set than web developers, and even then advantages of Linux escape me.

jamwil• 11 months ago

Some people work for large corporations and can’t just use whatever computer they want.

Mountain_Skies• 11 months ago

The FOSS community has become full of ideological landmines, with projects now including clauses in their requirements, often vague and ill defined, about how those who build upon their projects must act and believe. As a result, some are now finding it less risky to roll their own base dependencies instead of using someone else's project that could at any time become problematic for non-technical reasons.

While I doubt this had anything to do with the decision by the Zed team to make their own toolkit, it is something becoming more common. Hopefully it doesn't start happening in the encryption space.

wwfn• 11 months ago

I can see "ill defined" causing problems. But isn't an explicit code of conduct more defined than none? (Assuming I'm reading that correctly from your comment.)

There aren't too many epithets floating around that offend me specifically. And I haven't heard anyone say I shouldn't/don't exist. So it's hard for me personally to feel the need for CoC and the like. But I'm all for policy that protects everyone against that kind of abuse -- which seems to be on the rise. Are there better alternatives?

pjmlp6• 11 months ago

Or why you don't insist in using Khronos stuff on Windows, when most OEMs only care about the native API, DirectX.

Lets recap that this lesson has been learned by Godot developers, regarding their backends as well.

The ICD mechanism is a kind of escape hatch leftover due to backwards compatibility, and even user mode drivers build on top of DirectX runtime infrastructure.

leecommamichael3• 11 months ago

Is it Khronos? The 3 issues they linked were: 1. ARM support missing for one of their Cargo crates. 2. An issue with RemoteDesktop 3. The team required dynamic_rendering, and it wasn't available for user with an old machine on Windows 10.

It really depends how you define scope, but I don't think I would've taken on another GPU backend for that.

kermatt2• 11 months ago

What should they have used instead?

delta_p_delta_x10• 11 months ago

As mentioned here... Probably Skia, which would've saved them the effort of writing any GPU backend, let alone three.

Thaxll• 11 months ago

Why dx11 and not 12? No one should care about win7 in 2025.

Analemma_• 11 months ago

Think about the customer base: the sorts of users who want a high-performance text editor are exactly the kind of people who will run Windows 7 until it's pried from their cold, dead fingers, and who will flood the support forums with complaints if you limit support to operating systems released in the last 15 years. Because of their target market, Zed probably has implicit support requirements which wouldn't apply to e.g. the last first-person shooter.

delta_p_delta_x10• 11 months ago

Zed probably has implicit support requirements which wouldn't apply to e.g. the last first-person shooter.

This is incongruous given Zed uses modern frameworks (which is why they moved to D3D11 from Vulkan in the first place).

If Zed really wanted to target 'old Windows' then they might have used Win32 and GDI+, not D3D11. In fact they could've stuck to D2D (which was released with Windows 7 and back-ported to Vista), and not used their own rendering at all, since D2D is already a GPU-accelerated text-rendering API, and then used Win32 windowing primitives for everything else.

Someone• 11 months ago

Similarly, the Mac version is for MacOS 10.15 (from 2019) or later, and has an x64 version.

zamadatix2• 11 months ago

DX12 isn't just "newer DX11" though, so it really comes down to what makes the most sense for building Zed with.

delta_p_delta_x10• 11 months ago

I've written a response below, but the summary is that mapping from Vulkan 1.3 with dynamic rendering to D3D11 is easier than targeting the lower-level D3D12. The latter does have some form of dynamic rendering too, but I suspect the authors woud've had to re-think their CPU code much more than what has currently been done. Getting Windows Vista and 7 support is a freebie.

shortrounddev22• 11 months ago

Dx11 is a far more ergonomic API than dx12. Dx12 is what you use when you need maximum control over memory allocation and such

pjmlp6• 11 months ago

If you aren't trying to write a games engine, DX 11 is good enough, and won't be going away any time soon.

dang• 11 months ago

Related ongoing threads:

Zedless: Zed fork focused on privacy and being local-first - https://news.ycombinator.com/item?id=44964916

Sequoia backs Zed - https://news.ycombinator.com/item?id=44961172

munchler2• 11 months ago

I’m sure this is a dumb question, but why does a code editor need to render on the GPU like a video game? Is it just for niceties like smooth scrolling?

delta_p_delta_x10• 11 months ago

but why does a code editor need to render on the GPU like a video game?

It isn't just text editors—nowadays, everything renders on your GPU, even your desktop and terminal (unless you're on a tty). For example, at the bottom of Chromium, Electron, and Avalonia's graphics stack is Skia, which is a cross-platform GPU-accelerated windowing and 2D graphics library.

GPU compositing is what allows transparency, glass effects, shadowing, and it makes actually writing these programs much easier, as everything is the same interface and uses the same rendering pipeline as everything else.

A window in front of another, or a window partially outside the display? No big deal, just set the 3D coordinates, width, and height correctly for each window, and the GPU will do hidden-surface removal and viewing frustum clipping automatically and for free, no need for any sorting. Want a 'preview' of the live contents of each window in a task bar or during Alt-Tab, like on Windows 7? No problem, render each window to a texture and sample it in the taskbar panels' smaller viewports. Want to scale or otherwise squeeze/manipulate the contents of each window during minimise/maximise, like macOS does? Easy, write a shader.

This was a big deal in the early 2000s when GPUs finally had enough raw compute to always run everything, and basically every single OS and compositor switched to GPU rendering roughly in the same timeline—Quartz Extreme on Mac OS X, DWM.exe on Windows, and Linux's variety of compositors, including KWin, Compiz, and more.

There's a reason OSs from that time frame had so many glassy, funky effects—this was primarily to show off just how advanced their GPU-powered compositors were, and this was also a big reason why Windows Vista fell so hard on its face—its compositor was especially hard on the scrawny integrated GPUs of the time, enough that two themes—Aero Basic, and Aero Glass—had to be released for different GPUs.

munchler2• 11 months ago

Thanks. That explains why OSs use the GPU for rendering windows and effects, but it's still not clear to me why a code editor would do the same. The features you list (transparency, glass effects, shadowing, window management, etc.) seem to be outside the purview of a text editor.

If you're saying that Zed is built on something like Skia, then it would already be cross-platform and not have to worry about Vulkan vs. DirectX, right?

leecommamichael3• 11 months ago

It doesn't need to. It's typical to do this these days, but they could still arrange all of the pixels on the CPU and then blit it onto the screen. There's an API to do so in every major OS.

Since it's more than quick enough to do this on the CPU, they're likely doing it for things like animations and very high quality font rendering. There's image-processing going on when you really care about quality; oversampling and filtering.

I suspect one could do most everything Zed does without a GPU, but about 10 to 20% uglier, depending on how discerning the user is on such things.

ben-schaaf3• 11 months ago

Since it's more than quick enough to do this on the CPU

This is true until it isn't. A modern-ish CPU at 1080p 60hz it'll be fine. At 4k 120hz even the fastest CPU on the market won't keep up. And then there's 8k.

they're likely doing it for things like animations and very high quality font renderin

Since they're using native render functions this probably isn't the case.

starkrights• 11 months ago

The zed blog has an early post[0] talking some about their decision. Mainly just decrying their experience of impossible-to-meet timing deadlines for something as basic as 60fps on electron.

It doesnt really do a tech breakdown of why it’d be impossible CPU side, but mentions a couple of things about their design process for it.

[0] https://zed.dev/blog/videogame

spapas82• 11 months ago

For people that use scoop and want to try Zed there's a precompiled binary they can install using scoop install zed.

I tried it and the experience (mainly visually, fonts colours etc) wasn't very good so I can understand why the Zed developers are reluctant to formally release windows binaries.

Zed for Windows: What's Taking So Long?

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