Comment by saagarjha
18 hours ago
Modern CUDA programs that hit roofline look absolutely nothing like those from 10 or even 5 years ago. Or even 2 if you’re on Blackwell.
18 hours ago
Modern CUDA programs that hit roofline look absolutely nothing like those from 10 or even 5 years ago. Or even 2 if you’re on Blackwell.
But for research you often don't have to max out the hardware right away.
And the question is what do programs that max out Ironwood look like vs TPU programs written 5 years ago?
Sure, but you do have to do it pretty quick. Let’s pick a H100. You’ve probably heard that just writing scalar code is leaving 90+% of the flops idle. But even past that, if you’re using the tensor core but using the wrong instructions you’re basically capped at 300-400 TFLOPS of the 1000 the hardware supports. If using the new instructions but poorly you’re probably not going to hit even 500 TFLOPS. That’s just barely better than the previous generation you paid a bunch of money to replace.
They don't have to, CUDA is a high-level API in this respect. The hardware will conform to the demands of the market and the software will support whatever the compute capability defines, Nvidia is clearer than most about this.