62 pointsby surprisetalk4 hours ago27 comments
  • jawon42 minutes ago
    I was thinking about inhouse model inference speeds at frontier labs like Anthropic and OpenAI after reading the "Claude built a C compiler" article.

    Having higher inference speed would be an advantage, especially if you're trying to eat all the software and services.

    Anthropic offering 2.5x makes me assume they have 5x or 10x themselves.

    In the predicted nightmare future where everything happens via agents negotiating with agents, the side with the most compute, and the fastest compute, is going to steamroll everyone.

    • Aurornis3 minutes ago
      > Anthropic offering 2.5x makes me assume they have 5x or 10x themselves.

      They said the 2.5X offering is what they've been using internally. Now they're offering via the API: https://x.com/claudeai/status/2020207322124132504

      It's very unlikely that there's a 10X faster version anywhere. LLM APIs are tuned to handle a lot of parallel requests. In short, the overall token throughput is higher, but the individual requests are processed more slowly.

      This likely comes from having some servers tuned for higher individual request throughput, at the expense of overall token throughput. It's possible that it's on some newer generation serving hardware, too.

    • stavros11 minutes ago
      This makes no sense. It's not like they have a "slow it down" knob, they're probably parallelizing your request so you get a 2.5x speedup at 10x the price.
    • crowbahr15 minutes ago
      Where on earth are you getting these numbers? Why would a SaaS company that is fighting for market dominance withhold 10x performance if they had it? Where are you getting 2.5x?

      This is such bizarre magical thinking, borderline conspiratorial.

      There is no reason to believe any of the big AI players are serving anything less than the best trade off of stability and speed that they can possibly muster, especially when their cost ratios are so bad.

      • jawon5 minutes ago
        Not magical thinking, not conspiratorial, just hypothetical.

        Just because you can't afford to 10x all your customers' inference doesn't mean you can't afford to 10x your inhouse inference.

        And 2.5x is from Anthropic's latest offering. But it costs you 6x normal API pricing.

    • falloutx13 minutes ago
      Thats also called slowing down default experience so users have to pay more for the fast mode. I think its the first time we are seeing blatant speed ransoms in the LLMs.
      • Aurornis2 minutes ago
        That's not how this works. LLM serving at scale processes multiple requests in parallel for efficiency. Reduce the parallelism and you can process individual requests faster, but the overall number of tokens processed is lower.
      • throw31082210 minutes ago
        Slowing down respect to what?
        • falloutx7 minutes ago
          Slowing down with respect to original speed of response. Basically what we used to get few months back and what is the best possible experience.
          • throw3108222 minutes ago
            There is no "original speed of response". The more resources you pour in, the faster it goes.
  • paxys2 hours ago
    Looking at the "Decide when to use fast mode", it seems the future they want is:

    - Long running autonomous agents and background tasks use regular processing.

    - "Human in the loop" scenarios use fast mode.

    Which makes perfect sense, but the question is - does the billing also make sense?

  • Nition3 hours ago
    Note that you can't use this mode to get the most out of a subscription - they say it's always charged as extra usage:

    > Fast mode usage is billed directly to extra usage, even if you have remaining usage on your plan. This means fast mode tokens do not count against your plan’s included usage and are charged at the fast mode rate from the first token.

    Although if you visit the Usage screen right now, there's a deal you can claim for $50 free extra usage this month.

  • dmix16 minutes ago
    I really like Anthropic's web design. This doc site looks like it's using gitbook (or a clone of gitbook) but they make it look so nice.
  • niobean hour ago
    So fast mode uses more tokens, in direct opposition to Gemini where fast 'mode' means less. One more piece of useless knowledge to remember.
    • Sol-42 minutes ago
      I don't think this is the case, according to the docs, right? The effort level will use fewer tokens, but the independent fast mode just somehow seems to use some higher priority infrastructure to serve your requests.
  • clbrmbr3 hours ago
    I’d love to hear from engineers who find that faster speed is a big unlock for them.

    The deadline piece is really interesting. I suppose there’s a lot of people now who are basically limited by how fast their agents can run and on very aggressive timelines with funders breathing down their necks?

    • throw3108224 minutes ago
      The idea of development teams bottlenecked by agent speed rather than people, ideas, strategy, etc. gives me some strange vibes.
    • sothatsit2 hours ago
      If it could help avoid you needing to context switch between multiple agents, that could be a big mental load win.
      • an hour ago
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  • IMTDb3 hours ago
    I’m curious what’s behind the speed improvements. It seems unlikely it’s just prioritization, so what else is changing? Is it new hardware (à la Groq or Cerebras)? That seems plausible, especially since it isn’t available on some cloud providers.

    Also wondering whether we’ll soon see separate “speed” vs “cleverness” pricing on other LLM providers too.

    • kingstnap2 hours ago
      It comes from batching and multiple streams on a GPU. More people sharing 1 GPU makes everyone run slower but increases overall token throughput.

      Mathematically it comes from the fact that this transformer block is this parallel algorithm. If you batch harder, increase parallelism, you can get higher tokens/s. But you get less throughput. Simultaneously there is also this dial that you can speculatively decode harder with fewer users.

      Its true for basically all hardware and most models. You can draw this Pareto curve of how much throughput per GPU vs how many tokens per second per stream. More tokens/s less total throughput.

      See this graph for actual numbers:

      Token Throughput per GPU vs. Interactivity gpt-oss 120B • FP4 • 1K / 8K • Source: SemiAnalysis InferenceMAX™

      https://inferencemax.semianalysis.com/

    • sothatsit3 hours ago
      There are a lot of knobs they could tweak. Newer hardware and traffic prioritisation would both make a lot of sense. But they could also lower batching windows to decrease queueing time at the cost of lower throughput, or keep the KV cache in GPU memory at the expense of reducing the number of users they can serve from each GPU node.
    • Nition3 hours ago
      I wonder if they might have mostly implemented this for themselves to use internally, and it is just prioritization but they don't expect too many others to pay the high cost.
    • jstummbillig3 hours ago
      > It seems unlikely it’s just prioritization

      Why does this seem unlikely? I have no doubt they are optimizing all the time, including inference speed, but why could this particular lever not entirely be driven by skipping the queue? It's an easy way to generate more money.

      • singpolyma33 hours ago
        Until everyone buys it. Like fast pass at an amusement park where the fast line is still two hours long
        • sothatsit2 hours ago
          At 6x the cost, and it requiring you to pay full API pricing, I don’t think this is going to be a concern.
        • servercobra2 hours ago
          It's a good way to squeeze extra out of a bunch of people without actually raising prices.
    • re-thc21 minutes ago
      Nvidia GB300 i.e. Blackwell.
    • pshirshov3 hours ago
      > so what else is changing?

      Let me guess. Quantization?

  • pronik3 hours ago
    While it's an excellent way to make more money in the moment, I think this might become a standard no-extra-cost feature in several months (see Opus becoming way cheaper and a default model within months). Mental load management while using agents will become even more important it seems.
    • falloutx2 minutes ago
      Why would they cut a money making feature? In fact I am already imagining them asking for speed ransom every time you are in a pinch, some extra context space will also become buyable. Anthropic is in a penny pincher phase right now and they will try to milk everything. Watch them add micro transactions too.
    • giancarlostoro3 hours ago
      Yeah especially once they make an even faster fast mode.
  • simonw3 hours ago
    The one question I have that isn't answered by the page is how much faster?

    Obviously they can't make promises but I'd still like a rough indication of how much this might improve the speed of responses.

  • l5870uoo9y2 hours ago
    It doesn’t say how much faster it is but from my experience with OpenAI’s “service_tier=priority” option on SQLAI.ai is that it’s twice as fast.
  • rustyhancockan hour ago
    At this point why don't we just CNAME HN to the Claude marketing blog?
  • jonplackett16 minutes ago
    Is this is the beginning of the ‘Speedy boarding’ / ‘Fastest delivery’ enshitification?

    Where everyone is forced to pay for a speed up because the ‘normal’ service just gets slower and slower.

    I hope not. But I fear.

  • 11235813213 hours ago
    Could be a use for the $50 extra usage credit. It requires extra usage to be enabled.

    > Fast mode usage is billed directly to extra usage, even if you have remaining usage on your plan. This means fast mode tokens do not count against your plan’s included usage and are charged at the fast mode rate from the first token.

    • minimaxir3 hours ago
      After exceeding the increasingly shrinking session limit with Opus 4.6, I continued with the extra usage only for a few minutes and it consumed about $10 of the credit.

      I can't imagine how quickly this Fast Mode goes through credit.

    • arcanemachiner2 hours ago
      It has to be. The timing is just too close.
  • maz1b2 hours ago
    AFAIK, they don't have any deals or partnerships with Groq or Cerebras or any of those kinds of companies.. so how did they do this?
    • tcdent2 hours ago
      Inference is run on shared hardware already, so they're not giving you the full bandwidth of the system by default. This most likely just allocates more resources to your request.
      • AnotherGoodName10 minutes ago
        More specifically it just goes the to front of every queue. AI datacenters don't run your query on a specific GPU or server (or even a specific set of GPU's). They break every query you send them down into chunks, send it off into processing queues and put it back together at the end. Everything is architectured as pipelines of data aiming for constant 100% utilization at every stage on that expensive hardware. The way you achieve this is with constantly full queues of jobs ready to go at, ensuring there's no stalls in that pipeline at each stage.

        The queues add latency but are necessary to avoid under-utilization in any HPC environment. It's straighfoward to have priorities of jobs. Eg. you might want internal training to be low pri, inference from regular customers mid and then this, the top tier high pri. Keep every GPU/TPU fully utilized, anything less is an expensive waste of hardware.

    • hendersoon2 hours ago
      Could well be running on Google TPUs.
  • simianwords2 hours ago
    Whatever optimisation is going on is at the hardware level since the fast option persists in a session.
  • esafak2 hours ago
    It's a good way to address the price insensitive segment. As long as they don't slow down the rest, good move.
  • pedropaulovc3 hours ago
    Where is this perf gain coming from? Running on TPUs?
    • AnotherGoodName28 minutes ago
      AI data centers are a whole lot of pipelines pumping data around utilizing queues. They want those expensive power hungry cards near 100% utilized at all times. So they have a queue of jobs on each system ready to run, feeding into the GPU memory as fast as completed jobs are read out of memory (and passed into the next stage) and they aim to have enough backlog in these queues to keep the pipeline full. You see responses in seconds but at the data center you're request was broken into jobs, passed around into queues, processed in an orderly manner and pieced back together.

      With fast mode you're literally skipping the queue. An outcome of all of this is that for the rest of us the responses will become slower the more people use this 'fast' option.

      I do suspect they'll also soon have a slow option for those that have Claude doing things overnight with no real care for latency of the responses. The ultimate goal is pipelines of data hitting 100% hardware utilization at all times.

  • krm013 hours ago
    Will this mean that when cost is more important than latency that replies will now take longer?

    I’m not in favor of the ad model chatgpt proposes. But business models like these suffer from similar traps.

    If it works for them, then the logical next step is to convert more to use fast mode. Which naturally means to slow things down for those that didn’t pick/pay for fast mode.

    We’ve seen it with iPhones being slowed down to make the newer model seem faster.

    Not saying it’ll happen. I love Claude. But these business models almost always invite dark patterns in order to move the bottom line.

  • thisisauseridan hour ago
    Instead of better/cheaper/faster you just the the last one?

    Back to Gemini.

  • AnotherGoodNamean hour ago
    But waiting for the agent to finish is my 2026 equivalent of "compiling!"

    https://xkcd.com/303/

  • jhack3 hours ago
    The pricing on this is absolutely nuts.
    • nick494881712 hours ago
      For us mere mortals, how fast does a normal developer for through a MTok. How about a good power user?
      • snowfieldan hour ago
        A developer can blast millions of tokens in minutes. When you have a context size of 250k that’s just 4 queries. But with tool usage and subsequent calls etc it can easily just do many millions in one request

        But if you just ask a question or something it’ll take a while to spend a million tokens…

        • nick4948817129 minutes ago
          Seems like an opportunity to condense the context into 'documentation' level and only load the full text/code for files that expect to be edited?
  • henning9 minutes ago
    LLM programming is very easy. First you have to prompt it to not mistakes. Then you have to tell it to go fast. Software engineering is over bro, all humans will be replaced in 6 days bro
  • hmokiguess3 hours ago
    Give me a slow mode that’s cheaper instead lol
  • thehamkercat4 hours ago
    Interesting, output price is insane/Mtok
  • solidasparagus3 hours ago
    I pay $200 a month and don't get any included access to this? Ridiculous
    • pedropaulovc3 hours ago
      Well, you can burn your $50 bonus on it
    • bakugo3 hours ago
      The API price is 6x that of normal Opus, so look forward to a new $1200/mo subscription that gives you the same amount of usage if you need the extra speed.
      • MuffinFlavored3 hours ago
        I always wondered this, is this true/does the math come out to be really that bad? 6x?

        Is the writing on the wall for $100-$200/mo users that, it's basically known-subsidized for now and $400/mo+ is coming sooner than we think?

        Are they getting us all hooked and then going to raise it in the future, or will inference prices go down to offset?

    • kingforaday3 hours ago
      ..But it says "Available to all Claude Code users on subscription plans (Pro/Max/Team/Enterprise) and Claude Console."

      Is this wrong?

      • behindsight2 hours ago
        It's explicitly called out as excluded in the blue info bubble they have there.

        > Fast mode usage is billed directly to extra usage, even if you have remaining usage on your plan. This means fast mode tokens do not count against your plan’s included usage and are charged at the fast mode rate from the first token.

        https://code.claude.com/docs/en/fast-mode#requirements

      • sothatsit2 hours ago
        I think this is just worded in a misleading way. It’s available to all users, but it’s not included as part of the plan.
  • speedping3 hours ago
    > $30/150 MTok Umm no thank you
  • aabhayan hour ago
    What is “$30/150MTok”? Claude Opus 4.6 is normally priced at “$25/MTok”. Am I just reading it wrong or is this a typo?

    EDIT: I understand now. $30 for input, $150 for output. Very confusing wording. That’s insanely expensive!

    • stavrosan hour ago
      Yeah I don't understand. Is it actually saying that fast mode is ten times more expensive than normal mode? I cannot be reading this right.