Folding Forum

I have a spare GPU sitting around (an RTX 2070 Super), but unfortunately I can't fit a 2nd GPU in my main rig. I have an old 1st-gen Core i3-530 and a Dell motherboard sitting around that I could put the GPU into, and was wondering if a CPU that old (no AVX, etc.) can still support GPU folding. Thanks!

TiO2 wrote: ↑Sat Nov 15, 2025 5:43 am I have a spare GPU sitting around (an RTX 2070 Super), but unfortunately I can't fit a 2nd GPU in my main rig. I have an old 1st-gen Core i3-530 and a Dell motherboard sitting around that I could put the GPU into, and was wondering if a CPU that old (no AVX, etc.) can still support GPU folding. Thanks!

Never hurts to try. Install 64bit OS, and see what happens.
I am not aware of fahclient's requirement for CPU to have AVX. Just 64bit. As long as you do not try to fold on that CPU, you should be fine

Yes, first generation iX is the minimum requirement for GPU folding. I'm running an i7 920 and an i7 860 without issues.

Older CPUs (Core 2 Duo / Quad) won't be able to run GPU cores. They lacks SSE 4.2 support that is required.

I believe the current cpu cores are for
sse4.1, avx-256, or avx2-256

avx128?

No. ARM NEON is 128, I believe.

calxalot wrote: ↑Sun Nov 16, 2025 12:26 am No. ARM NEON is 128, I believe.

I thought x86 AVX was 128, AVX2 bumped it to 256

I’m looking at the buildbot settings. It is what I said, albeit the cores were previously built by someone else. Probably with github actions. So they could be different.

muziqaz wrote: ↑Sun Nov 16, 2025 11:37 amI thought x86 AVX was 128, AVX2 bumped it to 256

That was Intel SSE with the 128-bit registers; MMX was 64-bit and AVX introduced 256-bit registers. AVX is also when x86 picked up dedicated FMA instructions.

As for the original question, keep in mind you'll lose a measurable chunk of performance due to the lack of Resizable BAR on old chipsets. I have a thread posted in this same subforum (look down about five or six posts from this one) where I inadvertently stumbled into this performance issue on some of my home folding rigs. Suffice it to say, ReBAR can cost you somewhere between 5-15% of your GPU performance depending on WU.

If you've got a system board which is new enough to support PCIe 3, then it's at least possible there's a firmware modification out there on Github which could allow you to insert the ReBAR code into your (albeit, very old) motherboard. I have an ancient Z77 motherboard which now supports ReBAR thanks to a firmware module injection tool. Obviously do this at your own risk; I wasn't too worried about a decade-old board

Albuquerquefx wrote: ↑Mon Nov 24, 2025 7:07 pm

muziqaz wrote: ↑Sun Nov 16, 2025 11:37 amI thought x86 AVX was 128, AVX2 bumped it to 256

That was Intel SSE with the 128-bit registers; MMX was 64-bit and AVX introduced 256-bit registers. AVX is also when x86 picked up dedicated FMA instructions.

Alternative reality strikes again

You may be confusing the existence of AVX supporting 128-bit SIMD as well as 256-bit SIMD. As initially implemented by AMD the 128-bit SIMD instructions were often faster, some unofficially called that "AVX 128".

AVX2 then made most of the vector integer instructions 256-bit, before many were just 128-bit.

Joe_H wrote: ↑Mon Nov 24, 2025 7:31 pm You may be confusing the existence of AVX supporting 128-bit SIMD as well as 256-bit SIMD. As initially implemented by AMD the 128-bit SIMD instructions were often faster, some unofficially called that "AVX 128".

AVX2 then made most of the vector integer instructions 256-bit, before many were just 128-bit.

Yeah, I probably am misremembering it

I think you can be forgiven for not remembering the minutae from an instruction set that came out like 20+ years ago

Albuquerquefx wrote: ↑Mon Nov 24, 2025 7:53 pm I think you can be forgiven for not remembering the minutae from an instruction set that came out like 20+ years ago

Yeah, can't believe it has been 14 years since it showed up in Sandy bridge