Facebook likes wimpy cores, CPU subscriptions
6/21/2012 2:17 PM EDT
CPUs by subscription
In Facebook’s ideal future, it will be able to upgrade the CPUs in its systems every 18 months or even sooner, letting server DRAMs and network controllers remain in place for longer cycles. Today all three of those elements as well as power supplies are upgraded at once every three hyears because they are part of the same motherboard.
A new OpenRack specification the OpenCompute group launched recently would move at least the power supply from the board and into the rack. Facebook expects to get its first production OpenRack design into its data centers in July.
By the first half of next year, Facebook hopes to have a proof-of-concept system ready for test that will put on separate upgradable “sleds” the boot hard drives and network controllers. “The hardest thing to segregate is the CPU from the DRAM, but there are some technologies on the horizon to do that,” Frankovsky said.
In the medium term, Facebook foresees pulling CPUs in sockets on similar sleds with DRAM. The Web company expects to replace the CPUs where socket-compatible upgrades are available.
“The next phase is to use an edge connector that will not introduce incremental latency outside our timing boundaries,” said Frankovsky. “That could use a high-speed, low-latency optical interconnect, but no one knows what it would look like,” he said.
At that point, Facebook has proposed using a subscription model of buying processors “by clocks and cores per year.” The company would reuse as many old CPUs as it could but would sell or ask the processor vendor to re-sell the extra chips to another end user.
“This notion is one we just recently started sharing so we have had no real reaction to it yet,” said Frankovsky. “This is a thought that hasn’t graduated to an idea yet, but it could be win-win scenario,” he said.
Meanwhile, Frankovsky said he would like to see today’s network switches move from modules proprietary to the blade servers of various vendors to an open approach based on an interconnect such as PCI Express. I would love to see PCI Express switching and management get more mature,” he added.