Tell HN: GpuOwl/PRPLL, GPU software used to find the largest prime number • Hacker News Board

Re: Tell HN: GpuOwl/PRPLL, GPU software used to find the largest prime number

#41

Post by mpreda » Mon, Oct 28, 2024, 9:44 PM UTC

latchkey wrote: post #36

mpreda wrote: post #21

Earlier quoted context omitted.

Point taken. I need to improve the documentation and make it easier to start with. There is a lot of documentation and HowTos on the Mersenne Forums [1] where experienced users help newcomers, and that relieves effort from myself. [1] http://mersenneforum.org/

Thanks. Just some feedback. Ideally, I'd download something, compile it and then be able to just run the binary and have it start up and do something. Right now, it does nothing. Ideally, the app could even connect to some central server to get work, and just start chugging along doing whatever it needs to do. Heading to the forums, it is a mess of what looks like decades of information. Tons of it outdated. Much of…

No, you don't have to understand the algorithms in order to use the software.

But I understand your feedback. I put it on my list to make it really easy to see the software running once you have the executable.

There is one little complication though -- you do need a working OpenCL install in order to use GpuOwl. For example, for AMD GPUs, you'd need to install ROCm. On Nvidia GPUs you'd need a working install of CUDA.

Re: Tell HN: GpuOwl/PRPLL, GPU software used to find the largest prime number

#42

Post by mpreda » Mon, Oct 28, 2024, 9:52 PM UTC

Resolver wrote: post #27

mpreda wrote: post #18

Earlier quoted context omitted.

Indeed CUDA is nice due to the way it uses C++, integrates host and GPU code in a single file, and in the convenience of compilation. Basically I think CUDA is a bit easier to start with than OpenCL. OTOH CUDA only works on Nvidia, and that's a major limitation. GpuOwl uses heavily FP64 ("double" floating point), and FP64 is more readily available at consumer prices on AMD GPUs. We (the GIMPS project) use a lot of Ra…

Are there any potential benefits of using CUDA instead of OpenCL on Nvidia GPUs? Like, better driver support, ability to utilize Nvidia-specific features? Nvidia A100 GPU which was used to find a new Mersenne prime has specialized dedicated hardware like tensor cores, which on A100 can work not only for FP16 and FP32 but also for FP64. Are there any benefits of utilizing this capabilities?

Yes I expect there may be some micro-optimizations that are available on CUDA, such as using bits of PTX in places.

And if the GPU provides some sort of matrix-multiplication on FP64, that we're not currently making use of -- clearly that would be a big opportunity.

But somebody needs to implement it, profile, test.. on some HW.

Re: Tell HN: GpuOwl/PRPLL, GPU software used to find the largest prime number

#43

Post by mpreda » Mon, Oct 28, 2024, 9:57 PM UTC

Thank you all for the questions! This was basically my first submission on HN, I'm still learning how to do things around here, but the overall tone was gentle and encouraging. And my main take-away was that I need to make the software more user-friendly in order to help potential new users try it out -- I'll work on that.

Re: Tell HN: GpuOwl/PRPLL, GPU software used to find the largest prime number

#44

Post by latchkey » Mon, Oct 28, 2024, 10:10 PM UTC

mpreda wrote: post #41

latchkey wrote: post #36

Earlier quoted context omitted.

Thanks. Just some feedback. Ideally, I'd download something, compile it and then be able to just run the binary and have it start up and do something. Right now, it does nothing. Ideally, the app could even connect to some central server to get work, and just start chugging along doing whatever it needs to do. Heading to the forums, it is a mess of what looks like decades of information. Tons of it outdated. Much of…

No, you don't have to understand the algorithms in order to use the software. But I understand your feedback. I put it on my list to make it really easy to see the software running once you have the executable. There is one little complication though -- you do need a working OpenCL install in order to use GpuOwl. For example, for AMD GPUs, you'd need to install ROCm. On Nvidia GPUs you'd need a working install of CUD…

By default, we provision our machines for our customers, with Ubuntu and the latest version of ROCm.

The software compiled cleanly and easily, that part is very well done.

The flags on the software though are greek to me.