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Cerebras’ new monster AI chip adds 1.4T transistors

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Re: Cerebras’ new monster AI chip adds 1.4T transistors

#51

Post by philjohn »

xhrpost wrote: post #35

How can the chip itself consume that kind of power? Or is the 15kw value for the entire unit? That's like 10 residential space heaters all turned to max. I'm surprised that much heat could be dissipated over such a small surface area. Does it use refrigerant for cooling? If my math is correct, if you had a 6500BTU window air conditioner, you'd need 8 of them to move the heat from this chip.

Well, a single 7nm CPU (AMD Ryzen) can pull down 95 odd watts at peak, granted, the IO die is a fair bit of that as it's on an older process, but if you extrapolate that out across a giant wafer it's "only" 157 Ryzen 7's.

Re: Cerebras’ new monster AI chip adds 1.4T transistors

#53

Post by 01100011 »

This thing is awesome and, as someone working for a competitor, kind of scary. I applaud their approach though. I think we're a couple years off from it, but we'll probably see wider adoption of larger silicon, with more specialized functional units, which are used with a lower duty cycle to manage heat. If nothing else, they're probably developing some good IP and techniques to handle other sorts of ultra-mega-insane-scale-integration.

I wonder what their software stack looks like. Can they support the sort of virtualization and sharing you'd want to keep this expensive beast fully utilized 24/7?

Re: Cerebras’ new monster AI chip adds 1.4T transistors

#54

Post by YetAnotherNick »

xhrpost wrote: post #35

How can the chip itself consume that kind of power? Or is the 15kw value for the entire unit? That's like 10 residential space heaters all turned to max. I'm surprised that much heat could be dissipated over such a small surface area. Does it use refrigerant for cooling? If my math is correct, if you had a 6500BTU window air conditioner, you'd need 8 of them to move the heat from this chip.

It would melt if you just do air cooling. I did some math for liquid nitrogen which has heat of vaporization as 200 kJ / kg. It would boil 3600*15/200 = 270 kg of nitrogen every hour. Just insane.

Re: Cerebras’ new monster AI chip adds 1.4T transistors

#55

Post by robocat »

pradn wrote: post #22
systemvoltage wrote: post #3

Most interesting aspect of wafer-scale manufacturing is yield. Even if we have 95% chip yield, as the chip size approaches the wafer-level dimensions, I don't know off top of my head what the math would be but it is going to plummet drastically. My guess is that they're handling this in the chip logic. Building resiliency by turning off cells in the wafer that didn't yield. That begs the question, how are they probin…

The first Cerebras Wafer Scale Engine used "... breakthrough techniques in cross-reticle patterning, but with the level of redundancy built into the design, ensured a yield of 100%, every time." I'm unsure what to think of this. "When we spoke to Cerebras last year, the company stated that they already had orders in the ‘strong double digits’." And they cost 2- 2.5 million each! https://www.anandtech.com/show/15838/c…

"the price has risen from ~$2-3 million to ‘several’ million".

"The CEO Andrew Feldman tells me that as a company they are already profitable, with dozens of customers already with CS-1 deployed and a number more already trialling CS-2 remotely as they bring up the commercial systems".

Quotes from https://www.anandtech.com/show/16626/cerebras-unveils-wafer-...

Re: Cerebras’ new monster AI chip adds 1.4T transistors

#56

Post by mvanaltvorst »

kllrnohj wrote: post #41
teruakohatu wrote: post #30

Earlier quoted context omitted.

I did a double that when I realised that was Kilowatts not Watts. This chip uses more energy in an hour than the average household (in my country at least) does in a day. It may be a very large wafer but dissipating that heat is still very impressive.

It sounds like a lot but it almost isn't? Like this is ~50x bigger than an Nvidia A100, and the A100 pulls up to 400w. 50 * 400 ~= 20kW. So in terms of thermal density it's in-line with existing GPUs. That said, I'd be fascinated to see the cooling solution. Is it just a massive copper heatsink & a boatload of airflow? Typical approaches of using heatpipes to expand the heatsink won't really work with something this…

There's an image on their website[1], pretty huge water pumps.

"To solve the 70-year-old problem of wafer-scale, we needed not only to yield a big chip, but to invent new mechanisms for powering, packaging, and cooling it.

The traditional method of powering a chip from its edges creates too much dissipation at a large chip’s center. To prevent this, CS-2’s innovative design delivers power perpendicularly to each core.

To uniformly cool the entire wafer, pumps inside CS-2 move water across the back of the WSE-2, then into a heat exchanger where the internal water is cooled by either cold datacenter water or air."

[1]: https://cerebras.net/product/

Re: Cerebras’ new monster AI chip adds 1.4T transistors

#57

Post by mattkrause »

arisAlexis wrote: post #42
KETpXDDzR wrote: post #38

I think I once saw one of the founders with a wafer in an In n' out with a potential investor. Looking at what Apple achieved with their M1A and the demand for "AI" - or training neutral networks, what it really is - they have a lot of potential. At least as long as the AI bubble doesn't burst.

How can the future burst? It's like saying medicine will burst or physics

Same way as the last time: rampant over-promising and under-delivering, maybe catalyzed by some high profile mishaps.

Bubbles popping aren’t always evaluations of the objective quality of something; it could just be about its assumed value relative to other plausible options. Homes mostly don’t become uninhabitable when a real estate bubble pops.

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