Clément Grégoire
@lectem.bsky.social
French C++ developer, consultant & co-founder @ siliceum.
Performance optimization, multithreading, rendering APIs and game engines.
I know too much about Webkit and JS for my own good.
I do reverse engineering for fun!
Performance optimization, multithreading, rendering APIs and game engines.
I know too much about Webkit and JS for my own good.
I do reverse engineering for fun!
Ever wrote spin-locks or had to debug them?
I have, and I got tired of seeing (and writing) crappy ones, so I did a real investigation this time.
Spoiler: trust your OS.
siliceum.com/en/blog/post...
I have, and I got tired of seeing (and writing) crappy ones, so I did a real investigation this time.
Spoiler: trust your OS.
siliceum.com/en/blog/post...
Spinning around: Please don't! - siliceum
Embark on a journey about why you should sometimes trust your OS more than yourself.
siliceum.com
January 27, 2026 at 10:40 AM
Ever wrote spin-locks or had to debug them?
I have, and I got tired of seeing (and writing) crappy ones, so I did a real investigation this time.
Spoiler: trust your OS.
siliceum.com/en/blog/post...
I have, and I got tired of seeing (and writing) crappy ones, so I did a real investigation this time.
Spoiler: trust your OS.
siliceum.com/en/blog/post...
Can we all agree that OpenSSL sucks by requiring perl to build in 2026?
I'm not even asking for CMake support, just no stupid dependencies!
I'm not even asking for CMake support, just no stupid dependencies!
January 4, 2026 at 1:29 PM
Can we all agree that OpenSSL sucks by requiring perl to build in 2026?
I'm not even asking for CMake support, just no stupid dependencies!
I'm not even asking for CMake support, just no stupid dependencies!
Cup arrived right before Christmas, thanks @matt.godbolt.org
December 23, 2025 at 10:38 PM
Cup arrived right before Christmas, thanks @matt.godbolt.org
Reposted by Clément Grégoire
My "No Graphics API" blog post is live! Please repost :)
www.sebastianaaltonen.com/blog/no-grap...
I spend 1.5 years doing this. Full rewrite last summer and another partial rewrite last month. As Hemingway said: "First draft of everything is always shit".
www.sebastianaaltonen.com/blog/no-grap...
I spend 1.5 years doing this. Full rewrite last summer and another partial rewrite last month. As Hemingway said: "First draft of everything is always shit".
No Graphics API — Sebastian Aaltonen
Graphics APIs and shader languages have significantly increased in complexity over the past decade. It’s time to start discussing how to strip down the abstractions to simplify development, improve pe...
www.sebastianaaltonen.com
December 16, 2025 at 6:52 PM
My "No Graphics API" blog post is live! Please repost :)
www.sebastianaaltonen.com/blog/no-grap...
I spend 1.5 years doing this. Full rewrite last summer and another partial rewrite last month. As Hemingway said: "First draft of everything is always shit".
www.sebastianaaltonen.com/blog/no-grap...
I spend 1.5 years doing this. Full rewrite last summer and another partial rewrite last month. As Hemingway said: "First draft of everything is always shit".
Did I mention I hate the webdev ecosystem ?
December 10, 2025 at 3:13 PM
Did I mention I hate the webdev ecosystem ?
Today a new episode of "Web sucks"!
When handling import of an external library, ESBuild generates some kind of import table for the whole library.
But since it needs to mimick ESM modules, it creates the "exports" object using Getters instead of properties.
When handling import of an external library, ESBuild generates some kind of import table for the whole library.
But since it needs to mimick ESM modules, it creates the "exports" object using Getters instead of properties.
December 9, 2025 at 10:44 AM
Today a new episode of "Web sucks"!
When handling import of an external library, ESBuild generates some kind of import table for the whole library.
But since it needs to mimick ESM modules, it creates the "exports" object using Getters instead of properties.
When handling import of an external library, ESBuild generates some kind of import table for the whole library.
But since it needs to mimick ESM modules, it creates the "exports" object using Getters instead of properties.
Movie you’ve watched more than six times with a gif. Hard mode: no Stars (Wars nor Trek), LOTR, or Marvel, Disney Animated or Pixar.
December 8, 2025 at 8:44 AM
Movie you’ve watched more than six times with a gif. Hard mode: no Stars (Wars nor Trek), LOTR, or Marvel, Disney Animated or Pixar.
So UE5 has a tool that generates perf reports, with a whole Metadata generation thing (in XML) that allows to customize reports.
But it still displays averages for timings everywhere.
Oh, and their perf bench tool is implemented using 3layers of different technologies.
But it still displays averages for timings everywhere.
Oh, and their perf bench tool is implemented using 3layers of different technologies.
October 13, 2025 at 12:03 PM
So UE5 has a tool that generates perf reports, with a whole Metadata generation thing (in XML) that allows to customize reports.
But it still displays averages for timings everywhere.
Oh, and their perf bench tool is implemented using 3layers of different technologies.
But it still displays averages for timings everywhere.
Oh, and their perf bench tool is implemented using 3layers of different technologies.
Finally took the time to buy a licence for Fork. Truly the best UI for git, as it's the only one that never disappointed me. It's only missing Linux support but otherwise well worth its price.
@fork_dev@mastodon.social
@fork_dev@mastodon.social
September 23, 2025 at 8:42 AM
Finally took the time to buy a licence for Fork. Truly the best UI for git, as it's the only one that never disappointed me. It's only missing Linux support but otherwise well worth its price.
@fork_dev@mastodon.social
@fork_dev@mastodon.social
New blog post about my journey into the ETW depths, I had long wanted to look into it, now I'm starting to regret it (just a bit).
But this is great if you want to write your own tools for profiling!
www.siliceum.com/en/blog/post...
But this is great if you want to write your own tools for profiling!
www.siliceum.com/en/blog/post...
ETW Events and thread names - siliceum
Thread names are one of the most crucial information one can get system activity. However Windows ETW does not make it easy to retrieve!
www.siliceum.com
August 7, 2025 at 8:10 AM
New blog post about my journey into the ETW depths, I had long wanted to look into it, now I'm starting to regret it (just a bit).
But this is great if you want to write your own tools for profiling!
www.siliceum.com/en/blog/post...
But this is great if you want to write your own tools for profiling!
www.siliceum.com/en/blog/post...
@openvibe.social the app is really great except for one thing killing the experience for me on android:
No way to copy a link or open it on your browser because you hide the webview toolbar!
No way to copy a link or open it on your browser because you hide the webview toolbar!
July 11, 2025 at 5:29 PM
@openvibe.social the app is really great except for one thing killing the experience for me on android:
No way to copy a link or open it on your browser because you hide the webview toolbar!
No way to copy a link or open it on your browser because you hide the webview toolbar!
While writing test code for an article on sampling profilers, I ended up in analyzing methods for high resolution sleeps on Windows.
Follow me into the rabbit-hole of high resolution timers!
www.siliceum.com/en/blog/post...
Follow me into the rabbit-hole of high resolution timers!
www.siliceum.com/en/blog/post...
Windows and high resolution timers - siliceum
While writing test code for an article on sampling profilers, I ended up in analyzing methods for high resolution sleeps on Windows. Follow me into the rabbit-hole of high resolution thread sleeps and...
www.siliceum.com
June 26, 2025 at 8:26 AM
While writing test code for an article on sampling profilers, I ended up in analyzing methods for high resolution sleeps on Windows.
Follow me into the rabbit-hole of high resolution timers!
www.siliceum.com/en/blog/post...
Follow me into the rabbit-hole of high resolution timers!
www.siliceum.com/en/blog/post...
Tracy 0.12 was just released with thread wake-up visualization, added by yours truly!
Check it out github.com/wolfpld/trac...
Check it out github.com/wolfpld/trac...
Release Tracy Profiler 0.12 · wolfpld/tracy
For a more detailed change list, see https://github.com/wolfpld/tracy/blob/v0.12.0/NEWS.
CPU topology includes die
To enable better insight into potential performance pitfalls the profiler will now...
github.com
June 3, 2025 at 5:33 AM
Tracy 0.12 was just released with thread wake-up visualization, added by yours truly!
Check it out github.com/wolfpld/trac...
Check it out github.com/wolfpld/trac...
Just discovered @ap.brid.gy that let's you interact with Mastodon users!
But it requires people from there to enable it too so... A bit limited?
But it requires people from there to enable it too so... A bit limited?
May 27, 2025 at 11:06 AM
Just discovered @ap.brid.gy that let's you interact with Mastodon users!
But it requires people from there to enable it too so... A bit limited?
But it requires people from there to enable it too so... A bit limited?
Implemented a simple String Interning class for a client last week.
Physical memory usage:
Before: 1.9GB
After: 1.5GB
Using a preloaded cache: 1.3GB
I might be on to something here...
Physical memory usage:
Before: 1.9GB
After: 1.5GB
Using a preloaded cache: 1.3GB
I might be on to something here...
May 13, 2025 at 4:08 PM
Implemented a simple String Interning class for a client last week.
Physical memory usage:
Before: 1.9GB
After: 1.5GB
Using a preloaded cache: 1.3GB
I might be on to something here...
Physical memory usage:
Before: 1.9GB
After: 1.5GB
Using a preloaded cache: 1.3GB
I might be on to something here...
Reposted by Clément Grégoire
New blog post! "Load store conflicts", in which we look at some performance sensitive code that has surprisingly dramatic performance swings based on the compiler and the microarchitecture used. Reposts appreciated!
zeux.io/2025/05/03/l...
zeux.io/2025/05/03/l...
Load-store conflicts
meshoptimizer implements several geometry compression algorithms that are designed to take advantage of redundancies common in mesh data and decompress quickly - targeting many gigabytes per second in...
zeux.io
May 4, 2025 at 2:37 PM
New blog post! "Load store conflicts", in which we look at some performance sensitive code that has surprisingly dramatic performance swings based on the compiler and the microarchitecture used. Reposts appreciated!
zeux.io/2025/05/03/l...
zeux.io/2025/05/03/l...
This is the third time I find issues due to codebases using rpmalloc this year...
Spinlocking without any kind of pause/yield is such a bad idea.
One of my threads got stuck for 4.5s !!!!
At this point, I can only advise to stop using rpmalloc.
Spinlocking without any kind of pause/yield is such a bad idea.
One of my threads got stuck for 4.5s !!!!
At this point, I can only advise to stop using rpmalloc.
April 22, 2025 at 8:41 AM
This is the third time I find issues due to codebases using rpmalloc this year...
Spinlocking without any kind of pause/yield is such a bad idea.
One of my threads got stuck for 4.5s !!!!
At this point, I can only advise to stop using rpmalloc.
Spinlocking without any kind of pause/yield is such a bad idea.
One of my threads got stuck for 4.5s !!!!
At this point, I can only advise to stop using rpmalloc.
Really @microsoft.com ?
850MB for a godamn photo viewer that is slower and has a worse UX than the one shipped with Windows XP ?!
850MB for a godamn photo viewer that is slower and has a worse UX than the one shipped with Windows XP ?!
April 8, 2025 at 12:52 PM
Really @microsoft.com ?
850MB for a godamn photo viewer that is slower and has a worse UX than the one shipped with Windows XP ?!
850MB for a godamn photo viewer that is slower and has a worse UX than the one shipped with Windows XP ?!
Reposted by Clément Grégoire
One thing people really like about Superluminal is that it Just Works, and we’re trying hard to get that same experience on Linux.
But this platform sometimes really feels like it’s actively fighting against anything “just working” and it would really prefer you Do The Work tyvm.
But this platform sometimes really feels like it’s actively fighting against anything “just working” and it would really prefer you Do The Work tyvm.
April 4, 2025 at 1:29 PM
One thing people really like about Superluminal is that it Just Works, and we’re trying hard to get that same experience on Linux.
But this platform sometimes really feels like it’s actively fighting against anything “just working” and it would really prefer you Do The Work tyvm.
But this platform sometimes really feels like it’s actively fighting against anything “just working” and it would really prefer you Do The Work tyvm.
Reposted by Clément Grégoire
Graphics Programming weekly - Issue 385 - March 30th, 2025 www.jendrikillner.com/post/graphic...
April 1, 2025 at 2:22 PM
Graphics Programming weekly - Issue 385 - March 30th, 2025 www.jendrikillner.com/post/graphic...
Following my article from yesterday, this link was shared on the DirectX discord. It's a community ran database of information about GPUs and their features.
Pretty awesome and very useful to check compatibility!
Pretty awesome and very useful to check compatibility!
D3d12infoDB
d3d12infodb.boolka.dev
March 28, 2025 at 12:54 PM
Following my article from yesterday, this link was shared on the DirectX discord. It's a community ran database of information about GPUs and their features.
Pretty awesome and very useful to check compatibility!
Pretty awesome and very useful to check compatibility!
Finally published an article I wrote eons ago about D3D12 descriptors and easy optimisations that you can do.
This can save you both CPU time and memory!
www.siliceum.com/en/blog/post...
This can save you both CPU time and memory!
www.siliceum.com/en/blog/post...
Optimizing copy of null descriptors in D3D12 - siliceum
Discover how a few simple tweaks can help save CPU time and memory when using Direct3D12 desciptors.
www.siliceum.com
March 27, 2025 at 9:35 AM
Finally published an article I wrote eons ago about D3D12 descriptors and easy optimisations that you can do.
This can save you both CPU time and memory!
www.siliceum.com/en/blog/post...
This can save you both CPU time and memory!
www.siliceum.com/en/blog/post...
I'm always surprised by the fact that the first answer to "we have perf problems" is to change the language.
I mean, going native is obvious. But why didn't they start by using a proper profiler with instrumentation is beyond me.
I mean, going native is obvious. But why didn't they start by using a proper profiler with instrumentation is beyond me.
Today we're thrilled to announce our effort to port the TypeScript compiler and language service to native code, gaining a 10x speed boost in build times and editor responsiveness!
devblogs.microsoft.com/typescript/t...
devblogs.microsoft.com/typescript/t...
A 10x Faster TypeScript - TypeScript
Embarking on a native port of the existing TypeScript compiler and toolset to achieve a 10x performance speed-up.
devblogs.microsoft.com
March 12, 2025 at 5:16 AM
I'm always surprised by the fact that the first answer to "we have perf problems" is to change the language.
I mean, going native is obvious. But why didn't they start by using a proper profiler with instrumentation is beyond me.
I mean, going native is obvious. But why didn't they start by using a proper profiler with instrumentation is beyond me.
Lost almost a day due to newer DbgHelp versions suddenly failing to load my .pdb files...
Turns out they changed a small check that now requires all sizes to be 8bytes aligned.
The intent was clearly to check that alignment of array entries was correct, but it ended up checking the size too...
Turns out they changed a small check that now requires all sizes to be 8bytes aligned.
The intent was clearly to check that alignment of array entries was correct, but it ended up checking the size too...
February 17, 2025 at 10:25 PM
Lost almost a day due to newer DbgHelp versions suddenly failing to load my .pdb files...
Turns out they changed a small check that now requires all sizes to be 8bytes aligned.
The intent was clearly to check that alignment of array entries was correct, but it ended up checking the size too...
Turns out they changed a small check that now requires all sizes to be 8bytes aligned.
The intent was clearly to check that alignment of array entries was correct, but it ended up checking the size too...