Amazon’s James Hamilton is all in on ARM servers in the data center

Amazon’s data center efficiency expert James Hamilton weighs in on AMD’s announcement that it will be building ARM processors, and he is decidedly positive and likely already testing ARM processors in Amazon’s cloud services.

Hamilton writes:

Invariably what we see happening about once a decade is a high-volume, lower-priced technology takes over the low end of the market. When this happens many engineers correctly point out that these systems can’t hold a candle to the previous generation server technology and then incorrectly believe they won’t get replaced. The new generation is almost never better in absolute terms but they are better price/performers so they first are adopted for the less performance critical applications.  Once this happens, the die is cast and the outcome is just about assured. The high-volume parts move up market and eventually take over even the most performance critical workloads of the previous generation. We see this same scenario play out roughly once a decade.


I’ve never seen Hamilton so explicitly pro-ARM in the data center, particularly in terms of his surety that ARM will slowly gobble up more server workload. His fundamental analysis is correct and includes the fact that the bottleneck in a lot of data center workloads isn’t the CPU but other constraints like networking, storage or memory. Which is one more reason why cloud data centers would be willing to sacrifice some performance. Because they don’t necessarily need it. (Incidentally, many of the companies working so hard on ARM servers are also trying to solve a lot of the associated memory control and networking problems with parallel processing.)

Hamilton looks back at how UNIX replaced IBM mainframes, and x86 replaced UNIX, noting that high volume economics always trump performance. Which is why he loves ARM. We’ve never seen processor volumes at this level before. There were 7.6 million server units sold in 2010, but 6.1 billion ARM processors shipped last year. At that sort of volume, innovation moves quickly and Hamilton believes that the innovation will infect the data center very quickly.