Original URL: http://www.theregister.co.uk/2005/11/04/sun_rock_scout/
Sun employs scout to do dirty work on Rock chips
Niagara gets TCP/IP speed up
As part of a painfully slow and vague striptease, Sun Microsystems has started to describe a couple of techniques it will use to improve processor performance in its soon to be released Niagara chip and future Rock processor line.
Despite hinting a couple of years back that Niagara would have special technology for handling TCP/IP and SSL loads, Sun has stayed largely quiet on the subject. Recently, however, Sun confirmed to The Register that its Niagara processors and Solaris 10 operating system have been tweaked to handle these specialized tasks.
"It's a hardware and software combination," said Marc Tremblay, a Sun fellow and general chip guru. "It is kind of spreading the load through cores. You can interrupt the cores, and each one has a little oomph out there to accelerate things."
A number of companies have created TOE (TCP/IP Offload Engines) cards to handle the burden of TCP/IP requests. Such products, however, didn't promise to work well with Sun's Solaris operating system or simplified Niagara chips. So, Sun decided to tune Solaris for the Niagara parts and do some of the TOE work in software. Sun will also be able to have cores work on SSL requests and encryption.
In the Rock chips due out in 2008, Sun will employ a technique called a "hardware scout" to boost performance.
"We launch a hardware thread that has its own register file and that runs hundreds of cycles ahead of the main thread," Tremblay said. "It looks for land mines as a scout does and brings in all the interesting data."
The scout works while a main software thread is stalled and, via pre-fetching, helps bring data to the cache. Then when the main thread catches up much of the data it needs is already in memory.
Sun hopes that Niagara and Rock will revitalize its SPARC-based servers. The systems have fallen behind IBM's Power-based systems in raw performance.
The company has been most shy about providing more specifics on the Rock chips. Tremblay said the product will tape out next year and arrive on schedule in 2008. ®