Comment by gghh | Hacker News Reader

Comment by gghh | Hacker News Reader

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I'm sorry I don't understand. From the way you frame it, and the sentiment of the replies, seems like this is some scary big number. MacBook M3 Max is a beefy machine and doing inference means it's going at full send. 50W is... what tiny appliances consume. Sure it's more than reading emails but... it's still not a number to be shocked at. An on-the-go laptop has a TDP (max rated power) of 45W. Regular work laptop is 70W. Gaming laptop 230W. The servers I have in the lab on which I run benchmarks counting syscalls per seconds for days on end (you know, performance engineering!) are now going north of 1kW.

Washing machine 900W. Hair dryer 1500W. Pizza oven 2000W. So yeah, you say 50W, yeah sure same as video rendering or gaming I guess, yet not really an OMG-level number.

And frankly I'm not quite sure there's anything like economy of scale where it gets more efficient if you serve more users (like some sibling comments seem to imply).

Last thing, and I know many know but also many others don't or have forgotten: Watts is a rate of consumption, not an absolute amount. That is Joule, energy. So you say 50W, but what you pay for (or the planet pays, whatever) generally is the amount of energy, hence you need to say for how long that consumption was sustained. 50W over 2 hours, that's 100 Joules, the actual resource you consumed and paid for.

Power (watts) is like speed (m/s). You say 50 miles an hour, need to say how long was the drive, so we know how far you got.

50 watts over 2 hours is 100 watt hours (Wh) which is 360 kJ. A joule is a watt second. For reference, battery capacity is often measured in Wh and household electric power use in kWh.

Also, datacenter scale devices are almost certainly designed to minimize energy use per operation given comparable latency. You can still compete as an on prem consumer by (1) repurposing your existing hardware, which saves on high CapEx costs, (2) increasing latency, getting your answer computed in a longer time, which probably saves at least some power by design if you can leverage e.g. NPUs, or (3) running smaller or more bespoke models that aren't worthwhile for the bigger players to serve at scale.

There's also a likely gain in serving more requests in parallel, but it may have more to do with successfully amortizing memory access for model weights than any inherent increase in efficiency. Anyway, I've argued in sibling comments that you perhaps can also leverage this on consumer hardware for the special case of DeepSeek V4.

> _50 watts over 2 hours is 100 watt hours (Wh) which is 360 kJ._

Yes of course that was a brain fart of mine. Watt is Joule per second not certainly Joule per hour. I made the point of "lecturing" readers on power v. energy since Antirez (OP) wrote _"50W of energy usage..."_ (instead of power consumption) and it's a mistake people often make. So my side point was: ok 50W but for how long.

The other thing I'm arguing is 50W is nothing to be shocked by. I would like to see an argument for the opposite. I'd like to know what's the power consumption of playing eg. Baldur's Gate for a couple hours on a gaming rig and I wager we surpass that by a margin.

Now, the data center economy of scales. You're saying they almost certainly exists. Okay whatever I don't know. Requests served in parallel. Amortizing memory access for model weights. Likely. I'm writing this with some thinly veiled dismissive attitude because I believe that it would be very useful to have hard data on whether or not serving many users v. just one user makes LLMs more efficient. It's an important point with wide ranging implications.

If there is scale, like you claim, and one day a wealthy patron gifts me a 40k USD rig where I can run a frontier LLM locally, then I'd still be making selfish use of the commons (energy, which belong to the planet, all of us, that kinda stuff) because the efficient/responsible choice is to pool and use a cloud vendor (or pool your rig with neighbors etc).

But saying a machine can be more efficient if it serves many users sounds to me a bit like nine women making a baby in a month.

Keep in mind, I said serving many requests in parallel, not just many users. In fact it's even more efficient if you can batch the requests of a large subagent swarm in parallel since this allows for sharing a big chunk of context/KV cache not just the model weights. That's why I raised the possibility of leveraging this same efficiency with DeepSeek V4. If as a user I can get into the habit of just firing off a request to be cranked on in the background and be completed whenever, and I reach a compute-limited performance workload (just like the big inference labs that serve many users concurrently, only on a smaller scale since the overall compute bottleneck hits sooner) that's quite new wrt. local models. It used to be that we could only do that by spending huge amounts of money on very fast RAM and/or scaling out to multiple nodes.

A big cloud vendor does not face the same opportunity, they cannot leverage the repurposing of your own existing hardware. And they'll definitely want to minimize latency in order to get maximum throughput/utilization from the hardware they did buy, even at an emergy cost. That's why I was careful to note latency as a possible factor before.

Ah ok, sharing context/KV cache, I can see that helping. I need to learn more about DS V4, you seem to hint it has some advantages over previous generations in this respect. I haven't followed that closely to quite catch this argument, I'll check it out.

The basic argument is that its KV cache is roughly an order of magnitude more compact than previous Chinese models, which were already very compact compared to the likes of Gemma 4 (though that example is a bit of an extreme). If you pair this with the basic facts of how to maximize LLM inference performance at scale (this was recently talked about in a video lecture on the Dwarkesh Patel YouTube podcast) the case for doing slow batched inference on prem with DeepSeek V4, perhaps even with memory offload, becomes, as I see it, quite obvious. Of course, I'd like to be proven wrong!

Right, Dwarkesh's episode with Reiner Pope. Didn't watch the full video but as soon I saw both going to an old school blackboard with an actual chalk in hand I could tell they meant business hehe :) Thanks for recommending the vid and for the info about DS V4.

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