Has Cerebras solved the classic wafer-scale challenges?
Powering and cooling such a large device was also a big question mark. With the launch of its CS-1 system, a computer built around this extraordinary device, Cerebras has now revealed a few small practical details.
The CS-1 is 26” tall and occupies a third of a data centre rack (15 rack units). This system, says the company, can replace hundreds or thousands of GPUs, which would need dozens of racks. There is one WSE in each system and it is fed with 1.2 Tbps of data (twelve 100-Gigabit Ethernet lanes).
Documents released by Cerebras reveal that “powering and cooling the world’s largest and fastest processor chip is an exceptionally challenging undertaking,” and while they don’t say exactly how much power is required, they do give us a clue. Apparently, the system uses less than one-tenth of the power (per compute unit) that a GPU-based system would, and they also mention that a GPU-based system on the same scale would require hundreds of kilowatts. Perhaps it’s safe, then, to assume the CS-1 draws power in the tens of kilowatts range.