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The inefficiency of RL, and implications for RLVR progress

dwarkesh.com

21–30 of 50 posts

Re: The inefficiency of RL, and implications for RLVR progress

#21

Earlier quoted context omitted.

Thank god. Was driving me mad.

[flagged]

This is the first time I read that someone uses an acronym for ragebait purposes. The acronym "RL" is very well known. Dwarkesh's podcast is mostly AI related, so it's not a surprise that he will freely use acronyms. I think your take is very cynical.

Re: The inefficiency of RL, and implications for RLVR progress

#22
There's some insights there about the base rate of correct responses and pretraining to boost that. Basically searching a suboptimal versus optimal area of the model space at a suboptimal versus optimal rate.

I think the framing of the discussion in general is kind of misleading though, because it kind of avoids the question of "information inefficient about what?"

In RL, the model is becoming more informative about a stimulus-action-feedback space; in SL the model is becoming more informative about a stimulus-feedback space. RL is effectively "built for" searching a larger space.

In situations like the essay where you are directly comparing SL and RL, you're kind of saying for RL "the action space is restricted to dictionary X and the feedback space is binary yes or no" and for SL "the feedback space is restricted to dictionary X". So in a certain sense you're equating the RL action space to the SL feedback space.

In that case, maybe searching over suboptimal regions of the RL-action-SL-feedback space is inefficient. But the reason why, I think RL exists is because it generalizes to situations where the feedback and action space is bigger. Maybe you want to differentially associate different responses with different rewards, or sample a response space that is so large that you can't define it a priori. Then SL breaks down?

Maybe this is obvious but I guess I get a little uneasy about talking about information efficiency of RL and SL without a broader framework of equivalence and what information is being represented by the model in both cases. It seems to me RL is a kind of superset of SL in terms of what it is capable of representing, which maybe leads to inefficiencies when it's not being used to its fullest.

Re: The inefficiency of RL, and implications for RLVR progress

#23
post #10

The premise of this post and the one cited near the start ( https://www.tobyord.com/writing/inefficiency-of-reinforcemen... ) is that RL involves just 1 bit of learning for a rollout, rewarding success/failure. However, the way I'm seeing this is that a RL rollout may involve, say, 100 small decisions out of a pool of 1,000 possible decisions. Each training step, will slightly upregulate/downregulate a given training…

Dwarkesh's blogging confuses me, because I am not sure if the message is free-associating, or, relaying information gathered.

ex. how this reads if it is free-associating: "shower thought: RL on LLMs is kinda just 'did it work or not?' and the answer is just 'yes or no', yes or no is a boolean, a boolean is 1 bit, then bring in information theory interpretation of that, therefore RL doesn't give nearly as much info as, like, a bunch of words in pretraining"

or

ex. how this reads if it is relaying information gathered: "A common problem across people at companies who speak honestly with me about the engineering side off the air is figuring out how to get more out of RL. The biggest wall currently is the cross product of RL training being slowww and lack of GPUs. More than one of them has shared with me that if you can crack the part where the model gets very little info out of one run, then the GPU problem goes away. You can't GPU your way out of how little info they get"

I am continuing to assume it is much more A than B, given your thorough sounding explanation and my prior that he's not shooting the shit about specific technical problems off-air with multiple grunts.

Re: The inefficiency of RL, and implications for RLVR progress

#24
post #10

The premise of this post and the one cited near the start ( https://www.tobyord.com/writing/inefficiency-of-reinforcemen... ) is that RL involves just 1 bit of learning for a rollout, rewarding success/failure. However, the way I'm seeing this is that a RL rollout may involve, say, 100 small decisions out of a pool of 1,000 possible decisions. Each training step, will slightly upregulate/downregulate a given training…

Dwarkesh's blogging confuses me, because I am not sure if the message is free-associating, or, relaying information gathered. ex. how this reads if it is free-associating: "shower thought: RL on LLMs is kinda just 'did it work or not?' and the answer is just 'yes or no', yes or no is a boolean, a boolean is 1 bit, then bring in information theory interpretation of that, therefore RL doesn't give nearly as much info a…

He is essentially expanding upon an idea made by Andrej Karpathy on his podcast about a month prior.

Karpathy says that basically "RL sucks" and that it's like "sucking bits of supervision through a straw".

https://x.com/dwarkesh_sp/status/1979259041013731752/mediaVi...

Re: The inefficiency of RL, and implications for RLVR progress

#25

Earlier quoted context omitted.

Thank god. Was driving me mad.

[flagged]

RLVR is the more particular term of art in this domain.

VR stands for verified rewards and is the single bit per rollout that is the heart of the post. Maybe we can convince dang to update the title.

Re: The inefficiency of RL, and implications for RLVR progress

#26
recent results like PEFT-Bench (arxiv.org/abs/2511.21285) found that while SFT is efficient for formatting, it actually degraded Llama-3-8B's reasoning on math and code tasks compared to the base model.

So is RL required to preserve those logic circuits?

There seems to be a trade-off in compute-efficiency and format vs intelligence

Re: The inefficiency of RL, and implications for RLVR progress

#27
post #17

Earlier quoted context omitted.

[flagged]

[flagged]

Ok so now it's stupid or malicious to use RL as reinforcement learning on a blog about AI where everyone in the field has been referring to it as RL forever? Even wikipedia puts (RL) after reinforcement learning.

Re: The inefficiency of RL, and implications for RLVR progress

#28
post #5

Bit of a nitpick, but I think his terminology is wrong. Like RL, pretraining is also a form of *un*supervised learning

Usual terminology for the three main learning paradigms: - Supervised learning (e.g. matching labels to pictures) - unsupervised learning / self-supervised learning (pretraining) - reinforcement learning Now the confusing thing is that Dwarkesh Patel instead calls pretraining "supervised learning" and you call reinforcement learning a form of unsupervised learning.

A “pretrained” ResNet could easily have been trained through a supervised signal like ImageNet labels.

“Pretraining” is not a correlate of the learning paradigms, it is a correlate of the “fine-tuning” process.

Also LLM pretraining is unsupervised. Dwarkesh is wrong.

Re: The inefficiency of RL, and implications for RLVR progress

#29
i think in order to make this kind of argument you would need to be able to show all of the trajectories that are effectively reachable as a result of pre-training, and then how much effective pruning takes place as a result of total adjustment of the weights in response to one RL sample.

Re: The inefficiency of RL, and implications for RLVR progress

#30

Earlier quoted context omitted.

[flagged]

This is the first time I read that someone uses an acronym for ragebait purposes. The acronym "RL" is very well known. Dwarkesh's podcast is mostly AI related, so it's not a surprise that he will freely use acronyms. I think your take is very cynical.

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