AMD mulls custom ARM 64-bit server chips

Advanced Micro Devices may be willing to make custom ARM server chips for customers, much like it made custom chips for the Xbox One and PlayStation 4 game consoles.

The chip maker will consider customising its 64-bit ARM server processor to meet specific customer needs as a market for the new type of servers evolves, and the company gets better visibility of usage models, said Sean White, an engineer at Advanced Micro Devices, during a presentation at the Hot Chips conference in Cupertino, California.

ARM chips are used mostly in mobile devices and are yet unproven in servers. But there is growing interest in using the low-power processors for Web-hosting and cloud applications. AMD’s ARM server chips could go into dense servers and process such applications while saving power, White said.

“There are more and more of those applications that are showing up in big data centres,” White said. “They don’t want traditional high-end… database type workloads.”

No 64-bit ARM servers have shipped yet, but AMD said its chips will be in servers by year end. As ARM server use grows, the usage model will become clearer, and AMD has the architectural flexibility to tweak chips to meet the specific needs of customers, much like it did for Microsoft and Sony on their latest game consoles, White said.

“If you want to customise an SOC to exactly what you want, or to put on a piece of your [intellectual property]… you can do that in here,” White said.

He provided the example of possibly customizing I/O and ports for specific customers.

AMD also shared the technical details of its first 64-bit ARM processor called Opteron A1100, code-named Seattle, at Hot Chips. The company has already started shipping the chips to server makers for testing. The first Seattle servers are expected to ship by the end of this year or early next year. One of the first servers with the new chip could be AMD’s own SeaMicro server.

The company also makes x86 server chips, but is placing a big bet on ARM chips. Some of AMD’s ARM server competitors include AppliedMicro, and it will continue to contend with Intel on x86 servers, which dominates data centers. Intel is already making custom processors based on its Xeon chips for large data center customers like eBay.

AMD last year also started putting more emphasis on the custom chip business after the PC market declined. The company is already recording strong custom chip revenue thanks to the game consoles, which are shipping in the millions.

The Seattle server chip has two DDR3 and DDR4 memory channels, which is half that of the typical four memory channels in its x86 server chips. The ARM chip will have up to 4MB L2 cache, with two cores sharing 1MB. A total of 8MB of L3 cache is accessible to all eight cores.

New to ARM processors is ECC memory, which is important in servers to correct data errors. The 32-bit ARM processors did not have ECC memory, which is a common in x86 server chips.

Each Seattle CPU will support up to 128GB of memory, totaling up to 1TB for the eight CPU cores on Opteron-A1100. The 32-bit ARM chips supported only up to 4GB of memory.

Other features on the chip include engines to encrypt and decrypt data and to compress and decompress data. A TrustZone security engine establishes trusted execution zones to safely execute code without hurting system integrity.

Seattle supports a “Swiss army knife” of common interfaces such as 10-gigabit Ethernet, PCI-Express and SATA storage, White said.

AMD has already started shipping a reference board with the Seattle processor to select customers that want to write and test applications