Any quick thoughts from you who did a LOT of research

[kriesel]

Originally Posted by axn

Until such time as the 30.8 enhanced stage 2 is implemented in gpuowl, P-1 on GPU should not be considered. It would be great, however, if gpuowl could be modified to do stage 1 save files compatible with P95. Or if someone could write a converter script ...

That pronouncement seems to be a bit premature, as gpuowl has been released for a year, while prime95 v30.8 as I understand it is still beta at best, not the current prime95 release for production, 30.7b9 is. As I understand it, the advances for P-1 are most advantageous at exponent considerably below the wavefront. A 16GB GPU can perform P-1 in gpuowl all the way up to 1G exponent, while that would require AVX512 CPU, which might not be present in the system.
I look forward to George's possible eventual guidance on what makes sense, as he is a very well informed owner of both CPUs and fast GPUs.

[Mark Rose]

Originally Posted by Trilo

I'm almost wondering if getting an older threadripper model for a similar price for quad channel instead of dual channel would be viable. For example, I'm seeing the 2970wx 24 core system on Amazon right now for ~$800. I'll let someone with more experience chime in.

I don't think it would work out well. That's 6 cores per memory channel, usually at 2933 or 3200, so very memory starved. The 12 core 2920X would be a better fit. But I still wouldn't buy one these days as they're based on Zen+. Zen 3 is vastly superior. The 2970WX is easily matched by a 5950X for CPU performance, on a much cheaper platform, though the 5950X does lack memory bandwidth. Where the old Threadripper chips are still great is when you need a boatload of IO from the 48 PCIe gen 3 lanes.

I'd probably buy a 5800X3D for PRP/LL work. The cache is interesting. Or multiple ~65 watt quad cores with 128 MB memory for P-1.

[petrw1]

Originally Posted by Mark Rose

Or multiple ~65 watt quad cores with 128 MB memory for P-1.

Thanks ... and being new to AMD which are these?

[DrobinsonPE]

Originally Posted by petrw1

Thanks ... and being new to AMD which are these?

They are all still Zen 2
Ryzen 3-3100
Ryzen 3-3300X
Ryzen 3-4100

[Mark Rose]

Originally Posted by petrw1

Thanks ... and being new to AMD which are these?

I'd probably go Intel for power efficiency, performance, and price, as far as 4 core goes.

If going AMD, you definitely want Zen 3, and outside of mobile, it's 6+ cores. There is the 5300G, but it's OEM-only.

[petrw1]

Originally Posted by Mark Rose

I'd probably go Intel for power efficiency, performance, and price, as far as 4 core goes.

If going AMD, you definitely want Zen 3, and outside of mobile, it's 6+ cores. There is the 5300G, but it's OEM-only.

I'm thinking I want at least 8 cores and probably 64GB 3200 RAM

[Mark Rose]

Originally Posted by petrw1

I'm thinking I want at least 8 cores and probably 64GB 3200 RAM

If you're going with Zen 3, I'd suggest going with 3600 RAM, especially with 8 cores. That's an extra 12.5% memory bandwidth, and 8 cores will definitely use it.

Thinking of getting the 5800X3D? I'm really curious how it will perform.