New giant chip from Cerebras Systems
The new Deep Learning chip from Cerebras Systems is as big as your keyboard and the greatest ever.
No, you will not see that on your PC. But it's a striking example of what CPU designers think when they develop deep learning chips to accelerate server workloads.
When you've got used to thinking of CPUs and GPUs that fit in the palm of your hand, think again - Cerebras Systems says it's the biggest chip ever, one the size of your computer's keyboard .
Cerebras will unveil this Whopper of a Chip tonight at the Hot Chips conference at Stanford University. While the largest GPU includes 21,1 billion transistors and 815 square millimeter space required, the Cerebras Systems chip includes 1,2 trillion transistors and requires 46.225 square millimeter silicon. These are 71,64 square inches or a rectangular chip that would measure about 8 inches x 9 inches. It's so big that Cerebras has released photos that compare it to a PC keyboard!
No, the Cerebras chip is not designed for your PC. But is it real? Cerebras says they already have customer workloads running. But important details such as the number of cores and the amount of memory and the cost of manufacturing retained the company back. Interestingly, it is manufactured in a relatively old 16nm process technology by TSMC.
The specifications of the Cerebras system chips.
Cerebras developed its chip for deep learning, as a large and growing part of the workloads in the data center are called. Cerebras characterized his chip as a "wafer-scale" implementation of a neural network that essentially bundles the logic, the connection and the memory on a single piece of silicon. Although it can be costly to manufacture, the company believes that on-chip interconnects are both faster and less expensive than building and connecting discrete cores.
It is the eye-catching size of the chip, which, however, can not help but lift the eyebrows. Remember: Intel's original Itanium processor, code-named McKinley, was considered massive when it debuted 2002 with 221 million transistors. But the Cerebras chip has more transistors than McKinley over 5.000, in 56 times larger form! Even IBM's upcoming Power9 iteration, announced here at Hot Chips, has only 8 billion transistors.
Here is the Cerebras chip, pictured against a baseball as an additional scale.
Manufacturing such a huge chip poses a number of major challenges, including just manufacturing and cooling. Even making such a huge chip without manufacturing defects is simply impossible, Cerebras admits - every chip manufacturer suffers from manufacturing defects, and a certain number of “bad” chips on each wafer are simply discarded. In the case of Cerebras, the company designs redundant processing cores and believes that mistakes will render some of them unusable. (How many, however, the company didn't say. There are over 400.000 cores in total.) An I / O fabric that connects one core to the next can route around faulty cores.
The counterintuitive design of a single monolithic chip actually saves manufacturing costs. "Because it's just one chip, you get it all with much less power and less space," said Sean Lie, former chief hardware architect at SeaMicro, later acquired by AMD, and AMD's data center server solutions business .
Cooling such a massive chip requires more than just a heat sink and fan. Cerebras says there is a "cold plate" placed over the silicon that uses multiple vertically mounted water pipes to directly cool the chip. Since the chip is too big to fit in a conventional package, Cerebras developed its own design, combining a circuit board, the wafer, a custom connector that connects the two, and the cooling plate.
Numerous chips make their debut at the Hot Chips conference and will never be seen again. Cerebras will almost certainly fall into the same category - you will never see anything like this in a PC, and they may not even survive long-term in the server room. But the allure of hot chips is that you never really know what you're going to see - and the Cerebras processor is certainly amazing.
Test and picture: Cerebras Systems Translation and editing: Institute for Rare Earths and Metals
