Groups > sci.physics.relativity > #671502

GPU Cache Hierarchy: Understanding L1, L2, and VRAM (Re: L1,..,Ln caches are located on the CPU AND on the GPU)

From	Mild Shock <janburse@fastmail.fm>
Newsgroups	sci.physics.relativity, sci.math
Subject	GPU Cache Hierarchy: Understanding L1, L2, and VRAM (Re: L1,..,Ln caches are located on the CPU AND on the GPU)
Date	2026-07-20 19:42 +0200
Message-ID	<113lmlu$4s3m$2@solani.org> (permalink)
References	(4 earlier) <113kfb6$3b4e$1@solani.org> <113ks1o$23ub3$1@news.nntp4.net> <113l24o$3oqg$1@solani.org> <113lhp8$2521l$2@news.nntp4.net> <113lm4v$4rml$1@solani.org>

Cross-posted to 2 groups.

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Hi,

Just read something for once you alcoholic:

GPU Cache Hierarchy: Understanding L1, L2, and VRAM
https://charlesgrassi.dev/blog/gpu-cache-hierarchy/

Measuring Cache Efficiency

GPU profilers like NVIDIA Nsight, AMD Radeon
GPU Profiler, and RenderDoc expose cache hit
rates and memory throughput. Key metrics to watch:

- L1 Hit Rate: Should be >80% for well-optimized
     shaders. Below 60% indicates access pattern problems.
- L2 Hit Rate: Measures working set fit.
     Below 70% suggests texture thrashing or too many unique textures.
- Texture Memory Throughput: Compare to theoretical
     max. Low throughput with high latency = cache misses.
- Memory-bound vs Compute-bound: If memory is the
     bottleneck, cache optimization has highest impact.

If the GPU is a discrete GPU, it has VRAM,
If the GPU is an accelerator processing unit (APU),
it shares the system memory with the CPU.

In the APU scenrio often advanced unified memory
is used, which can be multi channel for example.
The high L1 and L2 hit rate for shaders, translates

also to pi-WAM. Which shows, in the example I used,
a quite good GPU saturation, less memory bound and
more compute bound. I have compute these figures already.

Bye

Mild Shock schrieb:
> Hi,
> 
> You are a moron right? Modern GPU has its
> own L1,..,Ln caches. RTFM ASAP you brain
> amputated vodka alcoholic.
> 
> Russian Hardbass - Crazy Dance
> https://www.youtube.com/watch?v=6OoglRuT0jY
> 
> Bye
> 
> Jeiker Makulov schrieb:
>> Mild Shock wrote:
>>
>>> Yes of course, Micro Penis will know. Nothing, LoL But here we find how
>>> village idiot Micro Penis is.
>>> The Cache Identity Crisis by Micro Penis:
>>>
>>> Claiming that L1/L2/L3 caches and core topology are "embedded cpu
>>> registers area,
>>> it has nothing to do with the ram." That is a brilliant piece of
>>> hardware fiction.
>>>
>>> Caches are SRAM acting as a hierarchical
>>
>> imbecile, formatting code like that puts you in prison in normal
>> countries. You are using entire lines for single chars, ie  "}" etc,
>> imbecile.
>>
>> also, fucking lying illiterate imbecile
>>
>> L1, L2, and L3 caches are located on the CPU, not in the system RAM. They
>> form a high-speed memory hierarchy embedded directly within or 
>> immediately
>> adjacent to the processor cores to minimize data access latency.
>>
>

Thread

I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) Mild Shock <janburse@fastmail.fm> - 2026-07-19 11:53 +0200
  Corr.: Re: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) Mild Shock <janburse@fastmail.fm> - 2026-07-19 11:55 +0200
  Re: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-19 14:04 -0700
    Re: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-19 14:07 -0700
      Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov (Was: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM]) Mild Shock <janburse@fastmail.fm> - 2026-07-20 08:31 +0200
        Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov (Was: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM]) Romelio Balakhonsky <lrel@lao.ru> - 2026-07-20 10:07 +0000
          The Cache Identity Crisis by Micro Penis (Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) Mild Shock <janburse@fastmail.fm> - 2026-07-20 13:51 +0200
            Just RTFM the RDNA 3.5 specs! [GPU Cache Lines] (Was: The Cache Identity Crisis by Micro Penis) Mild Shock <janburse@fastmail.fm> - 2026-07-20 14:09 +0200
              The large memory tax: ECC RAM (Was: Just RTFM the RDNA 3.5 specs! [GPU Cache Lines]) Mild Shock <janburse@fastmail.fm> - 2026-07-20 14:22 +0200
              Friendly Reminder: GPU 10x more performant than CPU (Re: Just RTFM the RDNA 3.5 specs! [GPU Cache Lines]) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:40 +0200
                Breaking the CUDA edge in AI by WebGPU (Re: Friendly Reminder: GPU 10x more performant than CPU) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:57 +0200
                Like WebAssembly before it, WebGPU has "escaped" the browser. (Re: Breaking the CUDA edge in AI by WebGPU (Re: Friendly Reminder: GPU 10x more performant than CPU) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:07 +0200
                Re: Breaking the CUDA edge in AI by WebGPU (Re: Friendly Reminder: GPU 10x more performant than CPU) Will Bakshandaev <bev@lwesi.ru> - 2026-07-21 14:33 +0000
                http://localhost:567921/ is a private REST endpoint [Teaching Micro Penis Vilage Idiot] (Was: Breaking the CUDA edge in AI by WebGPU) Mild Shock <janburse@fastmail.fm> - 2026-07-21 22:41 +0200
                If you are paranoid you can use Falco [Agentic AI] (Re: http://localhost:567921/ is a private REST endpoint) Mild Shock <janburse@fastmail.fm> - 2026-07-21 22:57 +0200
                What would an EMACs guru say [Windows Recall] (Was: If you are paranoid you can use Falco [Agentic AI]) Mild Shock <janburse@fastmail.fm> - 2026-07-21 23:33 +0200
                Re: http://localhost:567921/ is a private REST endpoint [Teaching Micro Penis Vilage Idiot] (Was: Breaking the CUDA edge in AI by WebGPU) Hants Baibikov <vi@bi.ru> - 2026-07-21 21:51 +0000
                Re: http://localhost:567921/ is a private REST endpoint [Teaching Micro Penis Vilage Idiot] (Was: Breaking the CUDA edge in AI by WebGPU) Pascual Talbaev <ps@laalapa.ru> - 2026-07-21 22:02 +0000
                Decide what you critique tiny winy penis (Was: http://localhost:567921/ is a private REST endpoint) Mild Shock <janburse@fastmail.fm> - 2026-07-22 08:13 +0200
                How confused is tiny winy penis? (Re: Decide what you critique tiny winy penis) Mild Shock <janburse@fastmail.fm> - 2026-07-22 08:29 +0200
                Maybe change your hobby, become a dog owner? (Re: How confused is tiny winy penis?) Mild Shock <janburse@fastmail.fm> - 2026-07-22 09:38 +0200
                Re: Decide what you critique tiny winy penis (Was: http://localhost:567921/ is a private REST endpoint) Audie Balaban <aie@ndabl.ru> - 2026-07-22 08:02 +0000
            Re: The Cache Identity Crisis by Micro Penis (Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) Jeiker Makulov <rmkru@eeeamu.ru> - 2026-07-20 16:18 +0000
              L1,..,Ln caches are located on the CPU AND on the GPU (Was: The Cache Identity Crisis by Micro Penis) Mild Shock <janburse@fastmail.fm> - 2026-07-20 19:33 +0200
                GPU Cache Hierarchy: Understanding L1, L2, and VRAM (Re: L1,..,Ln caches are located on the CPU AND on the GPU) Mild Shock <janburse@fastmail.fm> - 2026-07-20 19:42 +0200
                Re: GPU Cache Hierarchy: Understanding L1, L2, and VRAM (Re: L1,..,Ln caches are located on the CPU AND on the GPU) Zackee Mulatov <azauv@omtla.ru> - 2026-07-20 19:09 +0000
                Well thats good, co-location, onto the same processor die (Was: GPU Cache Hierarchy: Understanding L1, L2, and VRAM) Mild Shock <janburse@fastmail.fm> - 2026-07-20 22:02 +0200
                Where is micro penis mental error? (Re: Well thats good, co-location, onto the same processor die) Mild Shock <janburse@fastmail.fm> - 2026-07-20 22:07 +0200
                Re: Well thats good, co-location, onto the same processor die (Was: GPU Cache Hierarchy: Understanding L1, L2, and VRAM) Hermis Molochkov <me@olech.ru> - 2026-07-20 22:27 +0000
        Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov (Was: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM]) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 13:40 -0700
          I didn't find Futex in WebGPU / WGSL (Was: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) Mild Shock <janburse@fastmail.fm> - 2026-07-20 23:25 +0200
            Re: I didn't find Futex in WebGPU / WGSL (Was: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 14:32 -0700
              Re: I didn't find Futex in WebGPU / WGSL (Was: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 14:35 -0700
                There is no imageAtomicAdd in WGSL (Was: I didn't find Futex in WebGPU / WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:12 +0200
                OpenGL is dead. Apple said bye bye / Wayland Compositor (Was: There is no imageAtomicAdd in WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:24 +0200
                Re: There is no imageAtomicAdd in WGSL (Was: I didn't find Futex in WebGPU / WGSL) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 16:15 -0700
                Flogging a Dead Horse, OpenGL is EOL (Was: There is no imageAtomicAdd in WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:24 +0200
                imageAtomicAdd trivial, Dmitry Vyukov requires capacity (Re: Flogging a Dead Horse, OpenGL is EOL (Was: There is no imageAtomicAdd in WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:32 +0200
                capacity = 2^n for some n / systolic system (Was: imageAtomicAdd trivial, Dmitry Vyukov requires capacity) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:37 +0200
                Source of the benchmark for DmitryVyukov (Re: capacity = 2^n for some n / systolic system) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:45 +0200
                Re: imageAtomicAdd trivial, Dmitry Vyukov requires capacity (Re: Flogging a Dead Horse, OpenGL is EOL (Was: There is no imageAtomicAdd in WGSL) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 17:00 -0700
                I never used OpenGL Version 4.2 and later (Re: imageAtomicAdd trivial, Dmitry Vyukov requires capacity) Mild Shock <janburse@fastmail.fm> - 2026-07-21 08:49 +0200
                Because of MIMD you have to reassess algorithms (Was: I never used OpenGL Version 4.2 and later) Mild Shock <janburse@fastmail.fm> - 2026-07-21 08:59 +0200
                Why MIMD is interesting for pi-WAM? Mild Shock <janburse@fastmail.fm> - 2026-07-21 09:16 +0200
                Re: Why MIMD is interesting for pi-WAM? Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 00:32 -0700
                Re: Because of MIMD you have to reassess algorithms (Was: I never used OpenGL Version 4.2 and later) Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 00:42 -0700
                You still don't understand "budget" [Rossy Boy slower than Micro Penis] (Was: Because of MIMD you have to reassess algorithms) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:13 +0200
                Go on Rossy Boy, ask more stupid questions (Was: You still don't understand "budget" [Rossy Boy slower than Micro Penis]) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:17 +0200
                Need to be Einstein to understand Giga Lips (Was: Go on Rossy Boy, ask more stupid questions) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:22 +0200
                Marketing invents Gucci Bag AI Laptops (Was: Need to be Einstein to understand Giga Lips) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:43 +0200
                Re: Go on Rossy Boy, ask more stupid questions (Was: You still don't understand "budget" [Rossy Boy slower than Micro Penis]) Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 08:59 -0700
                Rossy Boy says I am a crazy frothing lunatic (Was: Go on Rossy Boy, ask more stupid questions) Mild Shock <janburse@fastmail.fm> - 2026-07-21 22:27 +0200
                Re: Rossy Boy says I am a crazy frothing lunatic (Was: Go on Rossy Boy, ask more stupid questions) Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 13:52 -0700

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