Toby Ord
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tobyord.bsky.social
Toby Ord
@tobyord.bsky.social
Senior Researcher at Oxford University.
Author — The Precipice: Existential Risk and the Future of Humanity.
tobyord.com
What ideas are already out there, just waiting on someone to really feel their power and bring them down from the ivory tower?
October 13, 2025 at 5:11 PM
During questions someone asked what we can learn about how to write an influential paper. Equally important is what we can learn about reading such a paper. So many philosophers had read it in the intervening generation, but none had taken it seriously.
October 13, 2025 at 5:05 PM
It made me realise for the first time that I was essential in making it so — that one Australian in Oxford in 1971 had thrown the ball far far down the field, to be received by another Australian in Oxford in 2004.
October 13, 2025 at 5:01 PM
So it looks like most of the gains are coming from the ability to spend more compute on each answer rather than from better ability to reason for the same token budget.
This shift to inference-scaling has big implications for AI business, governance, and risk:
www.tobyord.com/writing/infe...
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Inference Scaling Reshapes AI Governance — Toby Ord
The shift from scaling up the pre-training compute of AI systems to scaling up their inference compute may have profound effects on AI governance. The nature of these effects depends crucially on whet...
www.tobyord.com
October 3, 2025 at 7:39 PM
And here are the relative boosts.
Overall the inference scaling produced 82%, 63%, and 92% of the total performance gains on the different benchmarks.
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October 3, 2025 at 7:38 PM
As you can see, most of the boost is coming from the inference-scaling that the RL training has enabled.
The same is true for the other benchmarks I examined. Here are the raw scatterplots:
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October 3, 2025 at 7:37 PM
We can draw the trend on the chart, then divide the performance boost in two:
• the RL boost taking the base model to the trend line
• the inference-scaling boost taking it to the top of the trend
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October 3, 2025 at 7:37 PM
Note how there is a clear trend line for the reasoning models, showing how their performance scales with more inference. The base model is slightly below this trend.
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October 3, 2025 at 7:36 PM
I worked out a nice clean way to separate this out. Here is data from the MATH level 5 benchmark, showing performance vs token-use for a base model (Sonnet 3.6 – orange square) and its reasoning model (Sonnet 3.7 – red circles).
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October 3, 2025 at 7:35 PM
But it turns out that even when reasoning is turned off, these models are using many more tokens to generate their answers, so even this boost is partly just from RL and partly from the inference-scaling.
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October 3, 2025 at 7:35 PM
Often people assume it is mostly about the training. One piece of evidence for this is that even without reasoning turned on, a reasoning model seems to perform substantially better than its base model (i.e. a model that differs only in not having the RL training)
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October 3, 2025 at 7:34 PM
But it is hard to tease out how much of the benefits of RL are coming directly from the training (1) and how much are coming from using far more tokens to run it (2).
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October 3, 2025 at 7:33 PM
But (2) is less rosy.
For the largest AI companies, most costs come from deploying models to customers. If you need to 10x or 100x those costs, that is very expensive. And unlike training, it can't be made up in volume.
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October 3, 2025 at 7:33 PM
Many people focus on (1).
This is the bull case for RL scaling — it started off small compared to internet-scale pre-training, so can be scaled 10x or 100x before doubling overall training compute.
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October 3, 2025 at 7:32 PM
Scaling up AI using next-token prediction was the most important trend in modern AI. It stalled out over the last couple of years and has been replaced by RL scaling.

This has two parts:
1. Scaling RL training
2. Scaling inference compute at deployment

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October 3, 2025 at 7:31 PM