FP64 or FP32

marigonzes · 2017-02-10, 18:56

I have a question about the software. I was wondering if it makes more use of FP64 or FP32, i.e, double precision or single precision operations. I am thinking of acquiring a graphics card and I would like to take into account the needs of prime95.

Thank you.

Mark Rose · 2017-02-10, 20:22

Prime95 doesn't use a graphics card, but performs best with Intel CPUs supporting AVX2 and the all the memory channels populated with the fastest dual-rank memory supported by the CPU.

marigonzes · 2017-02-10, 20:28

Ok. And what about Trial Factoring on a GPU? Does it make a difference in that case?

VBCurtis · 2017-02-10, 21:02

The version of the software that does use a GPU, CUDALucas, uses DP operations for the lucas-lehmer test.

henryzz · 2017-02-10, 23:13

Quote:

Originally Posted by marigonzes

Ok. And what about Trial Factoring on a GPU? Does it make a difference in that case?

Trial factoring uses SP

TheJudger · 2017-02-11, 01:06

TF on GPU (mfakt[co]) is using 32bit (unsigned) integers most of the time.

2017-02-10, 18:56	#1
marigonzes Feb 2017 13 Posts	FP64 or FP32 I have a question about the software. I was wondering if it makes more use of FP64 or FP32, i.e, double precision or single precision operations. I am thinking of acquiring a graphics card and I would like to take into account the needs of prime95. Thank you.

2017-02-11, 01:06	#6
TheJudger "Oliver" Mar 2005 Germany 2³×139 Posts	TF on GPU (mfakt[co]) is using 32bit (unsigned) integers most of the time. Last fiddled with by TheJudger on 2017-02-11 at 01:06

2017-02-10, 20:22	#2
Mark Rose "/X\(‘-‘)/X\" Jan 2013 101110001001₂ Posts	Prime95 doesn't use a graphics card, but performs best with Intel CPUs supporting AVX2 and the all the memory channels populated with the fastest dual-rank memory supported by the CPU.

2017-02-10, 20:28	#3
marigonzes Feb 2017 13 Posts	Ok. And what about Trial Factoring on a GPU? Does it make a difference in that case?

2017-02-10, 21:02	#4
VBCurtis "Curtis" Feb 2005 Riverside, CA 3×1,777 Posts	The version of the software that does use a GPU, CUDALucas, uses DP operations for the lucas-lehmer test.