Re:eGPU: A 750 MHz Class Soft GPGPU for FPGA
by gsmecher on Tuesday August 01, 2023 @08:10PM
(#36965110)
> everything comes down to datapath.
Ain't that the truth.
However: Xilinx's DSP58 blocks (Versal devices), and older Intel DSPs, do integrate floating point into the DSP tiles - which does narrow the gap between the datasheet's DSP count and the number of floating-point operations achievable per clock.
Re:eGPU: A 750 MHz Class Soft GPGPU for FPGA
by mathisfun123 on Tuesday August 01, 2023 @09:28PM
(#36965790)
> Xilinx's DSP58 blocks (Versal devices)
this is correct (i am currently working on designs that target these parts) but those things are more expensive than comparably sized/equipped nvidia gpus so (in the context of this discussion) it's moot.
Re:eGPU: A 750 MHz Class Soft GPGPU for FPGA
by rzzzt on Wednesday August 02, 2023 @02:21AM
(#36967625)
Ballas mentions in a neighboring reply that the eGPU from the paper is using an Agilex 7: https://ark.intel.com/content/www/us/en/ark/products/217645/...
Re:eGPU: A 750 MHz Class Soft GPGPU for FPGA
by mathisfun123 on Wednesday August 02, 2023 @09:45AM
(#36970818)
Yes but as you can see by reading, this comment chain starts with someone linking to a xilinx product
You're giving completely the wrong impression about dsp slices - it is absolutely not 1 dsp slice per FP operator at any precision that you would want to do floating point arithmetic. It's definitely at least 2 plus a whole bunch of LUTs (~500) for FP16 with 4 stages or something like that. And if you want faster (fewer stages) then you need more slices. On alveo u280, which is an ultrascale part, I have never been able to effectively utilize more than ~4000 dsp slices (out of 9024) for 5,4 mults and that cost basically 99% of clbs in SLR1 and SLR2.
And even then, disconnected FPUs are completely meaningless without a datapath implementing eg matmul and boy oh boy do you have no clue what you're in for there.
Takeaway: it's pointless to compare raw specsheet numbers when everything comes down to datapath.