3 ms·
A64fx have on board HMB -> that means no dram. If you look at the fugaku mother board their is no Dimm slots. All the memory is on the same package as the CPU.
by blopeur 6y ago
A64fx have on board HMB -> that means no dram. If you look at the fugaku mother board their is no Dimm slots. All the memory is on the same package as the CPU.
This delivers a huge boost in bandwith.
HMB stand for high memory bandwidth. It offers up to 900 GB/s.
Now if you add the tofu interconnect on top you have a systems finely tuned for maximising data movement.
Remember : compute is cheap, communication is expensive.
You can have load of gpu and processors but if you can't feed them data fast enough they are useless.
- ViralBShah 6y agoThat is a pretty fun architecture. I hope that opens the door to higher performance for more workloads than top500. At least with the top500 benchmark, the bandwidth is not a problem, so long as you can do a large enough problem. Since it is a linear solve that spends all its time doing matmul (n^3 operations on n^2 data), so long as the problem is big enough, you can saturate the cores.
- lukevp 6y agoThat's fascinating. I know that AMD has been touting HBM as a faster memory subsystem for their GPUs, is that the same as HMB where it's stacked? Or are they just calling it something similar?
- blopeur 6y agoFor a more in depth dive : "Report on the Fujitsu Fugaku (富岳) System", Jack Dongarra, Jun 22, 2020 https://www.dropbox.com/s/aqntdb43p6so0z5/fugaku-report.pdf?dl=0 https://www.dropbox.com/s/aqntdb43p6so0z5/fugaku-report.pdf?...