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Maxim Saplin
Maxim Saplin

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Running Local LLMs, CPU vs. GPU - a Quick Speed Test

Updated on March 14, more configs tested

Today, tools like LM Studio make it easy to find, download, and run large language models on consumer-grade hardware. A typical quantized 7B model (a model with 7 billion parameters which are squeezed into 8 bits each or even smaller) would require 4-7GB of RAM/VRAM which is something an average laptop has.

LM Studio allows you to pick whether to run the model using CPU and RAM or using GPU and VRAM. It also shows the tok/s metric at the bottom of the chat dialog

LM Studio, perf metric

I have used this 5.94GB version of fine-tuned Mistral 7B and did a quick test of both options (CPU vs GPU) and here're the results.

Tokens/second

Spec Result
Apple M1 Pro CPU 14.8 tok/s
Apple M1 Pro GPU 19.4 tok/s
AMD Ryzen 7 7840U CPU 7.3 tok/s
AMD Radeon 780M iGPU 5.0 tok/s
AMD Ryzen 5 7535HS CPU 7.4 tok/s
GeForce RTX 4060 Mobile GPU 37.9 tok/s
AMD Ryzen 7 7800x3d CPU 9.7 tok/s
GeForce RTX 4080 GPU 78.1 tok/s

Hardware Specs

  1. 2021 M1 Mac Book Pro, 10-core CPU(8 performance and 2 efficiency), 16-core iGPU, 16GB of RAM

  2. 2023 AOKZEO A1 Pro gaming handheld, AMD Ryzen 7 7840U CPU (8 cores, 16 threads), 32 GB LPDDR5X RAM, Radeon 780M iGPU (using system RAM as VRAM), TDP at 30W

    • 3D Mark TimeSpy GPU Score 3000
    • 3D Mark TimeSpy CPU Score 7300
  3. 2023 MSI Bravo C7VF-039XRU laptop, AMD Ryzen 5 7535HS CPU (6 cores, 12 threads, 54W), 16GB DDR RAM, GeForce RTX 4060 (8GB VRAM, 105W)

    • GPU was slightly undervalued/overlocked, 3D Mark TimeSpy GPU Score 11300
    • 3D Mark TimeSpy CPU Score 7600
  4. Desktop PC, AMD Ryzen 7 7800x3d (8 cores 16 threads, 78w during test), 6200 DDR5, GeForce RTX 4080 16GB VRAM (slightly overclocked, 228w during test)

Screenshots

Mac

M1 CPU

M1 GPU

AOKZOE

7840U

780M

MSI

7535HS
RTX 4060

Desktop PC

7800x3d

RTX 4080

P.S>

Typing Test

It just hit me that while an average persons types 30~40 words per minute, RTX 4060 at 38 tokens/second (roughly 30 words per second) achieves 1800 WPM.

P.P.S>

Thanks to Sergey Zinchenko added the 4th config (
7800x3d + GeForce RTX 4080)

Top comments (20)

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adderek profile image
Maciej Wakuła

This depends much on the settings. I tried the same model and example query "tell me about Mars". Having Ryzen 3900 PRO CPU (12 cores, 24 threads, I got it for less than half price of 3900x), AMD RX 6700 (without x) which I also got cheap. RAM is pretty cheap as well so 128GB is in range of most. Using kobald-cpp rocm. With (14 layers on gpu, 14 cpu threads) it gave 6 tokens per second. (28,14) gave 15 T/s. (30,24) gave 4.43 T/s. Finally 35 layers, 24 CPU threads consumed total 7.3GB on GPU giving 34.61 T/s.

I'm writing to show that results depends very much on the settings.

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maximsaplin profile image
Maxim Saplin

JIC, I tested pure cases, 100% CPU and 100% offloading to GPU

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orlando_arroyo_1 profile image
Orlando Arroyo

How did you get to use 100% of the CPU?, which config or settings did you have?

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adderek profile image
Maciej Wakuła • Edited

You can offload all layers to GPU (CUDA, ROCm) or use CPU implementation (ex. HIPS). Just run LM Studio for your first steps. Run kobaldcpp or kobapldcpp-ROCm as second. Then try to use python and transformers. From there you should know enough about the basics to choose your directions. And remember that offloading all to GPU still consumes CPU

Image description

This is a peak when using full ROCm (GPU) offloading. See CPU usage on the left (initial CPU load is to start the tools, LLM was used on the peak at the end - there is GPU usage but also CPU used)
Image description

And this is windows - ROCm still is very limited on other operating systems :/

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orlando_arroyo_1 profile image
Orlando Arroyo

Adding some info here:

Running on a Razer Blade 2021 with a Ryzen 5900HX, a GF 3070Ti and 16GB RAM, I got 41.75tok/s. I used the same test as you, asking about Mars on the same model.

Hope that adds information to this very interesting topic.

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maximsaplin profile image
Maxim Saplin

Thanks for the contribution! I assume you used 100% GPU off-loading , right? Just checking:)

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orlando_arroyo_1 profile image
Orlando Arroyo

Indeed, 100%GPU off-loading.

I also tested an Ryzen 7950X with 0% off loading, but there’s something odd. I set 32 threads but CPU use is not going beyond 60% and only gets 7tok/s. Any thoughts how about possible cause?

Just for fun, I’ll check with an Asus ROG Ally later (Z1 Extreme version).

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maximsaplin profile image
Maxim Saplin

Seems the threads param is ignored, I saw same behaviour when testing CPU inference

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orlando_arroyo_1 profile image
Orlando Arroyo • Edited

Just for fun, here are some additional results:

iPad Pro M1 256GB, using LLM Farm to load the model: 12.05tok/s
Asus ROG Ally Z1 Extreme (CPU): 5.25 tok/s using the 25W preset, 5.05tok/s using the 15W preset

Update:
Asked a friend with a M3 Pro 12core CPU 18GB. Running from CPU: 17.93tok/s, GPU: 21.1tok/s

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maximsaplin profile image
Maxim Saplin

The CPU result for ROG is close to the one from 7840U, after all they almost identical CPUs

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clegger profile image
clegger

The ROG Ally has a Ryzen Z1 Extreme which appears to be nearly identical to the 7840U, but from what I can discern, the NPU is disabled. So if / when LM Studio gets around to implementing support for that AI accelerator the 7840U should be faster at inferencing workloads.

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maximsaplin profile image
Maxim Saplin

AMD GPU seems to be an underdog in the ML world, when compared to Nvidia... I doubt that AMD's NPU will see better compatibility with ML stack than it's GPUs

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bharath063 profile image
Bharath B

Intel i7 14700k - 9.82 token/s with no GPU offloading(peaked at 35% CPU usage in LMStudio. Guessing issue with multithreading)
Zotac Trinity non-OC 4080 Super - 71.61 tokens/s max GPU offloading

All numbers measured on non-overclocked factory default setup

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maximsaplin profile image
Maxim Saplin

Thanks for sharing the numbers!

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orlando_arroyo_1 profile image
Orlando Arroyo

Indeed there’s something odd with the multithreading of the CPUs

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orlando_arroyo_1 profile image
Orlando Arroyo

Just a quick update: using a RTX 4070 Super gets 58.2tok/s

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clegger profile image
clegger

In these tests is the 7840U utilizing the integrated NPU to accelerate the workload?

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maximsaplin profile image
Maxim Saplin

The result for "780M iGPU" is indeed the result coming from the GPU integrated into 7840U APU

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clegger profile image
clegger • Edited

@maximsaplin GPU != NPU
They are distinct accelerators.

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maximsaplin profile image
Maxim Saplin

NPU is not mentioned anywhere