This is fantastic. Really appreciate both the detailed deep-dive in the document, and the summary here. This is also timely, given that teams working on superscale models with concerning capabilities haven't generally been too forthcoming with compute estimates. (There are exceptions.)
As you and Alex point out in the sibling thread, the biggest remaining fudge factors seem to be:
Nonetheless, my flying guess would be that your method is pretty much guaranteed to be right within an OOM, and probably within a factor of 2 or less. That seems pretty good! It's certainly an improvement over anything I've seen previously along these lines. Congrats!
This seems pretty well done! Some thoughts on future research in this direction:
Thank you Alex! You make some great points.
It seems like you probably could have gotten certainty about compute for at least a handful of the models studied in question
We thought so too - but in practice it has been surprisingly hard. Profilers are surprisingly buggy. Our colleague Marious looked into this more in depth here.
Maybe we are just going the wrong way about it. If someone here figures out how to directly measure compute in eg a pytorch or TF model it would be a huge boon to us.
I think two more contemporary techniques are worth considering here: structured sparsity in weights ('blocksparse'), and mixture-of-experts gating ('switch transformer')
Great suggestions! I think those would be a great future caveats to look into.
I'd be curious to hear the authors' expectations of how this research changes in the face of more custom ML hardware.
My naive impression is that our conclusions do not change much. You would just need to plug into the effective performance () in the second formula.
Probably the trickiest part might be figuring out the utilization rate for the custom hardware - though this is a general problem with the second method.
In general I think it'd be good to integrate a bunch of the performance benchmarks that are publicly available (since hardware providers are usually pretty eager to show off stats that make their hardware look good) into calibrations for this method.
I think that would be nice! We started a public spreadsheet with some info on different hardware. This might be of help to someone who wants to dig deeper into the topic!
Comparing custom ML hardware (e.g. Google's TPUs or Baidu's Kunlun, etc) is tricky to put on these sorts of comparisons. For those I think the MLPerf Benchmarks are super useful. I'd be curious to hear the authors' expectations of how this research changes in the face of more custom ML hardware.
I'd be pretty excited to see more work on this. Jaime already shared our hardware sheet where we collect information on GPUs but as you outline that's the peak performance and sometimes misleading.
Indeed, the MLPerf benchmarks are useful. I've already gathered their data in this sheet and would love to see someone playing around with it. Next to MLPerf, Lambda Labs also shares some standardized benchmarks.
by Jaime Sevilla, Lennart Heim, Marius Hobbhahn, Tamay Besiroglu, and Anson Ho
You can find the complete article here. We provide a short summary below.
In short: To estimate the compute used to train a Deep Learning model we can either: 1) directly count the number of operations needed or 2) estimate it from GPU time.
Method 1: Counting operations in the model
2×# of connectionsOperations per forward pass×3Backward-forward adjustment×# training examples×# epochsNumber of passes
Method 2: GPU time
training time×# cores×peak FLOP/s×utilization rate
We are uncertain about what utilization rate is best, but our recommendation is 30% for Large Language Models and 40% for other models.
You can read more about method 1 here and about method 2 here.
Other parts of interest of this article include:
Complete Article
You can find the article here.