Show HN: Npunlock – Run custom C kernels for Intel NPUs

Show HN: Npunlock – Run custom C kernels for Intel NPUs github.com

Write and run custom C kernels for Intel Core Ultra NPUs - hsfzxjy/npunlock

67 points•hsfzxjy•9 days ago•16 comments•

#custom #intel #npunlock #kernels #npus #run custom #intel npus #write

16 comments

Author here. Feel free to ask any questions :)

Nice work! I have been messing with doing some radio DSP on the NPU in my laptop and found the Intel graph compiler to be rather unpredictable. Weird random mis-lowering to fp16 ops instead of int8, unpredictable throughput depending on tensor sizes, reshapes being sometimes extremely expensive and sometimes basically free etc.

Obviously I am mostly just driving the DPU, as the SHAVE cores are just not beefy enough, but maybe this will be useful at some point, at least to gain more insight into the architecture...

hsfzxjy8 days ago

Thanks! I can observe similar behaviors on my laptop. FP32 operations are sometimes siliently lowered to a sequence of (FP32->FP16)->(FP16 OP)->(FP16->FP32), causing precision loss. It further frustrated me during npunlock development. Changing custom SHAVE OP from FP16 -> FP32 also changes the blob structure, and I have to explore different binary patching strategy.

As for the interesting cost variance for reshape you've mentioned, I guess surrounding context is the cause. The NPU compiler might adjust the data layout to match successive OPs' requirements. But, yes, that's annoying~

Studying DPU is not my current priority, but I may dig it up in the future to understand its invocation descriptor, and hopefully to discover more interesting stuff. I hope this project ends up being useful to you!

alightsoul6 days ago

I failed a few days ago to use the npu with openvino and llama.cpp. I will try again with this and hopefully open source it. Thanks

Of course I will do everything on Linux. Might contribute back

hsfzxjy6 days ago

I have added a prober program which can run specific tests on linux and generate reports. This should be a nice start.

Bayard_ne8 days ago

Finally, bare-metal NPU programming! Immediately thought of those custom, weird inference tasks Intel won't ever officially support.

alightsoul6 days ago

Finally npus can be like cuda. Why did Intel limit themselves to openvino? Didn't want to take on the burden of something like cuda? Maybe they want to separate consumer and business NPUs from data center products which use oneapi which is more like cuda

hsfzxjy6 days ago

Seems that Intel prefer to provide a unified interface across different hardwares so hiding the low-level stuff is convenient. It was told by someone worked at Intel in another reddit thread.

https://www.reddit.com/r/ReverseEngineering/s/hv2N41pXO5

hsfzxjy8 days ago

Let's play Doom on NPU!

Gigachad8 days ago

What is this useful for?

hsfzxjy8 days ago

The main use is enabling developers to write their own NPU kernels according to their respective need, instead of picking workaround from what Intel provides in OpenVINO. I think the project would benefit three scenarios:

1. Implement uncommon NN operators.

2. Implement a high-precision (FP32, etc.) version of existing OpenVINO operators for numerically sensitive usage.

3. Implement a mega kernel that fuse several small kernels together to reduce SHAVE invocations, and potentially improve performance.

But most importantly, it gives you more control over the hardware you own. That control IMO should have been yours from day one you bought the machine.

alex7o8 days ago

Pls do hexagon next

Read the full thread on Hacker News →

16 comments

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