We found an approach to get Jev-like properties from standard LLMs like GLM-5.3-Flash. The core idea is to craft the input prompt so that the first output token answers the question. This makes it possible to get a…
The core idea is to craft the input prompt so that the first output token answers the question. This makes it possible to get a decision with a single forward pass.
In the blog post, we describe the approach in detail for GLM-5.3-Flash and vLLM. We benchmark this setup against Jev and Laya. We find that our setup is on-par with Jev in terms of accuracy and speed and that it substantially outperforms Laya.
Still, in terms of costs per decision, Jev is several x better than our setup. In turn, our setup supports vision inputs.
59 comments
I took a random book excerpt with 23,000 words (±30k input tokens) and used it as context. Jev still responds in 800ms, sometimes 500ms. That's in the neighbourhood of 20-50,000 tok/s prefill, which is obviously not possible with normal LLMs, not even Cerebras is this fast.
The Laya model compared in TFA shows one way Jev may be getting it's speed and low cost - by using a BERT-like bidirectional model rather than an auto-regressive one (LLM).
i have tested jev for my use cases and its horrendously wrong, but then the follow up from jev's team is "oh, you need to boil the question down further". it's a spiral of how much do you wanna dumb down the ask so that it answers it correctly. i'll pass for now.
also, 30k input tokens is a lot.
Off the top of my head, I would skip all the modern linear attention / state space stuff and use classical attention. But run prefill in a fully sliding-window mode so that “state” tokens simply don’t attend to far away tokens, or maybe also allow everything to attend to the first few tokens (and train like this). Now prefill is almost embarrassingly parallel, and you can make it fully parallel by duplicating work at block boundaries. (I’m not saying this is an awesome architecture if you want excellent results, but I’m also not convinced that Jev gives excellent results…)
The let queries attend to everything.
And architect the stack around this. Don’t try to cache the KV data — process the queries as you go so that the each input block and layer’s K and V data is computed, attended to, and discarded.
I’m curious whether Cerebras actually is a good device for this. Cerebras is kind of low on RAM, but if you don’t need to store KV data, maybe the entire computation fits on the die.
Getting competitive accuracy with Jev is fairly easy, if by accuracy you mean that the highest weighted answer is the right one. GLM 5.3 is complete overkill, much smaller llms will do
What Jev brings to the table, beyond speed, is that the reported probabilities match actual likelyhoods. If you present three options, with A and B equally likely and C impossible, jev will approximately answer with 0.5, 0.5, 0. Stock LLMs don't
You can even do it with small not particularly hard to host local LLMs like a variant of Qwen 3.6 35B A3B or 3.8 27B.
https://developers.openai.com/api/docs/guides/structured-out...
I should also add that the source comes from one of about 400 possible places and in a variety of messed up formats, it's the raw feed from a news scraper...
Because it's proprietary? By using an open weight model you're guaranteed that you can access it forever; if one provider bans you then you can go to another one (or you can self-host). With a proprietary, single-provider model locked behind an API if your access is revoked you're screwed.
Fyi, I haven't tested this yet.
When it comes to the high volume market of business automation, it seems that ultra-low cost, rather than expensive frontier intelligence, is exactly what you want, and low latency is also nice to have for customer-facing applications like customer service chatbots.
When I hear “architecture” I am thinking number of parameters and latency.
When I hear “accuracy” I think training recipe, data, and (later) number of parameters.
So when you say that Jev’s architecture may not be necessary, the evidence I expect to see is comparable quality at comparable latency. Not equal quality at 2x latency and 4x the cost.
But it is likely more than just a fine tune + novel training. At the very least the LM head is swapped out for a classifier one and then or also idk, bidirectional attention for the encoding pass I'm out of my depth at this point and will stop guessing. The training is probably where they have the biggest moat though, not that it's necessarily huge.
I have a project that fits jev as advertised almost comically well and I've been playing with it, and the various hacks and open versions. Jev doesn't necessarily perform better overall but it is quite different. It's sensitive to prompt phrasing in ways the others aren't, it's easy to generate questions where all the other models cluster in confidence but jev is an outlier. Not necessarily more correct, but it does feel like it's getting its answers in a different way.
I'm guessing just as much as anyone else but I've been spending a ton of time on this the last couple weeks, it landed right when I was most ready to dig into it.
Read the full thread on Hacker News →
Related stories
- The Verge · 0 points · 5 days ago
- The Verge · 0 points · 3 days ago
- Can John Ternus find Apple’s next big thing?theverge.comThe Verge · 0 points · 10 days ago
- Lobsters · 86 points · about 1 year ago
- The Verge · 0 points · 12 days ago
- Can you forget how you feel about Meta?theverge.comThe Verge · 0 points · 9 days ago