Step 5 Preview: Advancing the Pareto Frontier

(stepfun.com)

59 points | by nateb2022 5 hours ago ago

16 comments

  • nh43215rgb 4 hours ago

      > Built on a sparse Mixture-of-Experts architecture, Step 5 Preview has 600B total parameters, with 27B active per token, and supports a 1M-token context window and vision input.
    
      > Step 5 Preview scores 44 on the Artificial Analysis Intelligence Index.
    
      > The model will be released with open weights on October 15.
    
    I guess being Chinese company they decided to skip version 4, while also giving impression to be on the similar iteration with leading companies (claude opus 5). I wonder if other Chinese labs like Kimi/Moonshot will follow suit.
    • JohnsonZou an hour ago

      Another possible reason is that the number 4 is considered unlucky in traditional Chinese culture.

    • Bolwin 2 hours ago

      Moonshot has already teased K3.1 so not likely

      • dannyw 2 hours ago

        K3.1 would likely be a deeper/longer post-train from K3, so that’d make sense.

        It’s all marketing anyways, but that’s at least how a lot of labs have been naming things (sometimes).

  • bethekind 4 hours ago

    > Without any Pokémon-specific optimization, Step 5 Preview has so far sustained progress for more than 3,000 turns and 6 million tokens of interaction. By turn 3,082, it had unlocked Cut, earned three Gym Badges, and defeated Lt. Surge. The run is now roughly one-third of the way through the main story.

    Finally FireRed is being used as a benchmark again! I believe Astra can beat it in 18 hours. Not sure how that compares.

  • garo-pro an hour ago

    IT's Artificial Analysis Index is the same as Kimi K3, which is about 4.6x bigger, and GLM 5.3, which is about 1.25x bigger. Pricing is $1/$2.70 i/o. Openweights on October 15.

  • ghoshbishakh 3 hours ago

    Their posisitoning is nice. Instead of saying they are cheaper and a bit less performant (in terms of intelligence), they say they are best among the cheaper and a bit less performant ones.

  • Jacques2Marais 4 hours ago
    • sieve 4 hours ago

      I regularly hit 200-300M cached reads every day on some of the models I use. It has exceeded 7-800M on a couple of occasions. At $0.04/M, that is $8-12 per day only for cached reads.

      • ignoramous 3 hours ago

        > At $0.04/M

        Unless you meant step-3.7-flash, the input cache hits are $0.05 per mil for step-5-preview.

        > $8-12 per day only for cached reads

        Pretty decent "API" rates for ~500M+ tokens on Step Fun 5, a Kimi K3 / GLM 5.3 level model?

        Their "Step Plan" is ridiculous, by comparison: ~$60 usage on $6.99/mo; ~$220 on $9.99/mo. https://platform.stepfun.ai/docs/en/step-plan/overview

        • sieve an hour ago

          Yes, I meant the Flash version.

          I have used Kimi 2.5 and GLM 5.3 (& 5.3 Flash). Do not need them for what I do outside of spec hardening (basically, a lot of chatting).

          I tend to know exactly what I want and most of the weaker models are enough to get me there. I have mainly been using MiMo, DeepSeek V4 Flash and MuseSpark Contributor over the last month or so.

  • conception 4 hours ago

    Huh wonder why they skipped 4?

    • Alpha3031 4 hours ago

      Sometimes 4 is skipped due to being considered unlucky.

      • adrian_b 3 hours ago

        In China and in places influenced by Chinese culture, due to homonymy between "4" and death.

    • cynerx 2 hours ago

      Sounds like death in Chinese.

  • derliebej an hour ago

    How about adding a contested historical facts benchmark?