Fern @fernbear.bsky.social · 03/02/2025Having cross-entropy as a default is great, and is really nice for unlabeled data since it all tenda to fall out pretty nicely w.r.t. the learning process, but it is inherently (and necessarily) a much more expensive way to learn a target distribution of values. 020
Fern @fernbear.bsky.social · 03/02/2025Having (a good set of) crowdsourced values for a KL divergence would reduce this variance a bit, and also would give a better value to measure against, due to not being as noisy (in both bias _and_ variance -- a bit of a messy combo to deal with). 120
Fern @fernbear.bsky.social · 03/02/2025When aiming for a 94% accuracy (~6% error rate), this means that that 9% of the remaining labels are "bad", from a cross-entropy perspective. This is quite a lot! And partially one thing that made testing speedrun results more difficult. 110
Fern @fernbear.bsky.social · 03/02/2025Variance can be a problem in testing models, which extends iterative research cycle length due to needing to run more experiments. One paper that covered this, arxiv.org/abs/2103.14749, estimated the CIFAR-10 error rate to be at about .54% or so.arxiv.orgPervasive Label Errors in Test Sets Destabilize Machine Learning BenchmarksWe identify label errors in the test sets of 10 of the most commonly-used computer vision, natural language, and audio datasets, and subsequently study the potential for these label errors to affect b... 110
Fern @fernbear.bsky.social · 03/02/2025This is a classic example of _why_ choose-one-of-n datasets need to have large-scale, crowd-sourced statistics and should use the KL-divergence instead of cross-entropy. Reviewers will be more biased than a crowd, it's a high variance+bias estimator, it can harm research. 120
Reposted by FernTed Underwood @tedunderwood.com · 01/12/2024Did you know that attention across the whole input span was inspired by the time-negating alien language in Arrival? Crazy anecdote from the latest Hard Fork podcast (by @kevinroose.com and @caseynewton.bsky.social). HT nwbrownboi on Threads for the lead. 1924653
Fern @fernbear.bsky.social · 30/11/2024Okay, that is definitely way too aggressive. Hopefully it's not the case that it's like that long-term -- my hope is that with pushback against overzealous moderation that they change their stance on things like this. Should not be an auto-ban. 140
Fern @fernbear.bsky.social · 28/11/2024Yeah that's why he checks it twice, gotta be something like an approximate Radix sort followed by an insertion sort, I'd guess. P efficient maybe? 000
Reposted by FernEthan @ethansmith2000.com · 28/11/2024it's crazy to me that RoPE's issue with BF16 wasn't noticed earlier. For a reasonable N of 2048, these are the computed frequencies prior to cos(x) & sin(x) for fp32 above and bf16 below. Given how short the period is of simple trig functions, this difference is catastrophic for large values. 181
Fern @fernbear.bsky.social · 27/11/2024Having flexattention w/ DDP is really nice Also the foreach norm bug is apparently a bother to a few people 120
Reposted by FernEthan @ethansmith2000.com · 25/11/2024Just added FSDP2 support for MARS and Muon! 182
Fern @fernbear.bsky.social · 25/11/2024Thanks for 100 followers, y'all! Happened so fast and can't wait to put out more research on here! 😊❤️ 170
Fern @fernbear.bsky.social · 25/11/2024(And one more thing -- if this was the other site, I'd place a note saying to come and follow me on here. But we're already here, woo! Congratulations us. ❤️ Feel free to drop me a message and say hi, I'd love to chat! ❤️👍) 010
Fern @fernbear.bsky.social · 25/11/2024My time is funded by a combination of personal consulting/contracting work I take, as well as the financial support of others to enable this kind of open source work. If you'd like to help sponsor my time, check out at github.com/sponsors/tys... (or feel free to drop me a DM, would love to chat!)github.comSponsor @tysam-code on GitHub SponsorsSupport open-source research and human-accessible neural network speedrunning benchmarks 110
Fern @fernbear.bsky.social · 25/11/2024Finally, if you'd like to help see more open-source research work like this, consider sponsoring my time! 100
Fern @fernbear.bsky.social · 25/11/2024Funding for time as well as Colab compute for this work was generously supported by my supporters on Patreon (@jamorton_, @go2carter.bsky.social, @sroeker, @baberb.bsky.social, @chhillee.bsky.social, and @haitchai), as well as the generous support of @algomancer.bsky.social as well. 140
Fern @fernbear.bsky.social · 25/11/2024And this is not all from the research from compute provided from them, I've got more in the pipeline to come! Keep an eye out. ;) 100
Fern @fernbear.bsky.social · 25/11/2024First, my sincerest thanks to @leonardoai.bsky.social with the help of @ethansmith2000.com for generously providing H100s to support this research to enable this release. Y'all rock, thanks so much! <3 121
Fern @fernbear.bsky.social · 25/11/2024Thanks to FlexAttention (thanks @chhillee.bsky.social and folks), this was very straightforward to implement via attention masking. Great to be able to port some of that work to this speedrun and see it fly! <3 :) 100
Fern @fernbear.bsky.social · 25/11/2024Fun fact! This is actually a spiritual port of the sequence_length warmup originally implemented in hlb_gpt earlier last year. However, this was extremely hard to do until now due to the nature of how torch.compile worked. 110
Fern @fernbear.bsky.social · 25/11/2024Lowering Adam betas 0.9->0.8 to be a bit more nimble, as well as shortening the momentum warmup in a requisite manner, as well as increasing the number of cooldown steps for the network. 110
Fern @fernbear.bsky.social · 25/11/2024Some of the other changes include some hyperparameter changes to accommodate the increasingly-shortening learning schedules (1750 now vs 3000 two records ago!). 120
Fern @fernbear.bsky.social · 25/11/2024...This means we need an extra step for traditional comparisons, but also shortens the dev loop and biases us towards favoring longer-context learning) 120
Fern @fernbear.bsky.social · 25/11/2024(Now, a note on scoring -- this is because the modded-nanoGPT speedrun scores the model by the lowest possible validation loss as long as it is causal, vs a fixed attention context length... 120
Fern @fernbear.bsky.social · 25/11/2024As a result of the better match between context length during training and the network's learning dynamics, we can train a bit faster! With the increased context length, we are able to remove 125 steps, making this network 6.7% more data efficient than before. 120
Fern @fernbear.bsky.social · 25/11/2024(This also means that for this record, not only is the number of steps is lower -- the average stepsize is faster as well!) 120
Fern @fernbear.bsky.social · 25/11/2024The previous record used a sliding window size of 1024, whereas this record starts at a window size of 64 and linearly anneals it to 1792 over the course of training. This means we can spend more time learning longer context lengths where it matters -- at the end of training! 120
Fern @fernbear.bsky.social · 25/11/2024This record modifies the previous FlexAttention record by adding a warmup to the sliding window size over the course of training. Since our network can't necessarily utilize long-term connections at the start of training, this yields a pretty good boost to training speed! 130
Fern @fernbear.bsky.social · 25/11/2024New NanoGPT training speed record: 3.28 FineWeb val loss in 4.66 minutes Previous record: 5.03 minutes Changelog: - FlexAttention blocksize warmup - hyperparameter tweaks 2333
Reposted by FernBirchlabs @birchlabs.co.uk · 19/11/2024NATTEN just added fused support for self-cross attention! so you can attend to local neighbourhood and registers or text condition. it lets you reduce partial attention results (e.g. logsumexp provided by xformers APIs) into its LSE. github.com/SHI-Labs/NAT...github.comSupport for fused cross-NA by alihassanijr · Pull Request #182 · SHI-Labs/NATTENAdds experimental support for additional context tokens to Fused NA. Any number of partial attention results can be reduced into a final one as if their contexts were merged, which is just the same... 091
Fern @fernbear.bsky.social · 24/11/2024Here! (You followed originally on cifar10/LLM speedrunning IIRC) 100
Reposted by FernPeyman Milanfar @docmilanfar.bsky.social · 24/11/2024Radon Transform (RT) was formulated in 1917 but remained useless in practice until CT scanners were invented in the 60s But RT isn't just for CTs. It's a sort of generalization of marginals in probability RT g(p,θ): Shoot rays at θ+90 & offset p, measure line integrals of f(x,y) along the ray 1/n 28512
Reposted by FernEthan @ethansmith2000.com · 23/11/2024Here, have PSGD-Kron and SOAP with FSDP2 support. Please go wild with it, let's see something finally replace ADAM. github.com/ethansmith20... 3135
Reposted by FernEthan @ethansmith2000.com · 23/11/2024probably the best in-depth explanation i've seen on FSDP at the most granular levels, props to the authors dev-discuss.pytorch.org/t/fsdp-cudac... 193
Fern @fernbear.bsky.social · 24/11/2024Same. Looks like it's finally happening tho, I think! (Maybe!?) My Twitter feed is slowly turning into a ghost town. 110
Fern @fernbear.bsky.social · 22/11/2024Welcome, @gabrielpeyre.bsky.social ! Great to have you here. 000
Fern @fernbear.bsky.social · 22/11/2024(Minor caveat, this seems to apply less to approximate second-order optimizers better than Adam, but still seems to be a problem) 000
Fern @fernbear.bsky.social · 22/11/2024One example: Trying to warn people beforehand: x.com/hi_tysam/sta... "I told you so" afterwards: x.com/hi_tysam/sta...x.comx.com 110
Fern @fernbear.bsky.social · 22/11/2024I am an extremely grumpy ML person, give me an add! I dedicate nearly half an hour every day to shaking a stick at the energetic younguns to keep 'em in shape. 100