logoalt Hacker News

Gemini last models: temperature, top_p, and top_k are deprecated and ignored

75 pointsby greatgibyesterday at 9:27 PM24 commentsview on HN

Comments

bob1029today at 6:59 AM

> To improve determinism, define a system instruction with explicit rules for your specific use case.

What if I want to do the other thing? When performing research with many sub agents, having a lot of diversity in the hypotheses is a big deal. If my 5 parallel sub agents all produce the same conclusion I might as well have only ran one.

The latest OAI models have done the same thing. I'm currently adding random variation to prompts to compensate for the lack of higher temperature sampling.

salamotoday at 2:34 AM

Possible reasons:

- They might be dynamically adjusting these at inference time [1]. For example, start with a low temperature and generate samples with increasingly high temperatures until one of them passes some quality gate.

- They don't want you to fine-tune on high temperature completions (rejection fine-tuning). You could call this "rejection fine-tuning rejection".

[1] https://rlhfbook.com/c/09-rejection-sampling#related-best-of...

aesthesiayesterday at 11:40 PM

My guess is that RL training being done with particular generation parameters makes models much more brittle to changes in these parameters, and that's why we're seeing changes like this across model providers. But I don't really know.

show 3 replies
herpderperatortoday at 5:45 AM

I'm curious: If someone wanted to serve models off hardware/silicon directly (like Cerebras or Taalas, and soon Google I think) rather than GPUs, would these parameters still be adjustable at request time? Or would they have to decide that before the model can even start serving and it would be locked in until they reload it (which would make it briefly unavailable)?

franky47today at 6:27 AM

> To improve determinism, define a system instruction with explicit rules for your specific use case.

"Please be deterministic".

nichoheltoday at 4:15 AM

"Last" or "latest"? Those are rather different.

show 1 reply
kouteiheikatoday at 12:56 AM

Obligatory "The Conspiracy Against High Temperature Sampling":

https://gist.github.com/Hellisotherpeople/71ba712f9f899adcb0...

show 2 replies
tolugeniusyesterday at 11:13 PM

> To improve determinism, define a system instruction with explicit rules for your specific use case.

Is this guaranteed to work any better than top_k or top_p? This just sounds like making a smaller version of a Agent.md doc.

show 2 replies
toughyesterday at 11:24 PM

fwiw sonnet-5 also drops temperature (sonne-4 had it)

charcircuittoday at 2:59 AM

Along with everything else. These parameters can make speculative decoding less accurate increasing the inference cost.

gdiamostoday at 2:31 AM

thank god, these parameters are so confusing

greatgibyesterday at 9:27 PM

1. Sampling parameter deprecation (temperature, top_p, top_k)

temperature, top_p, and top_k are deprecated and ignored. In future model generations, supplying these parameters returns an HTTP 400 error. Remove these parameters from all requests.

impulser_yesterday at 11:53 PM

Good. These have been basically useless for the past few generations of models, and most of the time made the model perform worst.

double2025today at 6:44 AM

[flagged]