High-performance throughput computing

CMT processors offer a way to significantly improve the performance of computer systems. The return on investment for multithreading is among the highest in computer microarchitectural techniques. If you design a core from scratch to support multithreading, gains as high as 3/spl times/ are possible for just a 20 percent increase in area. Even with throughput performance as the main target, we have shown that the microarchitecture necessary to support threads on a CMT can also achieve high single-thread performance. Hardware scouting, which Sun is implementing on the Rock microprocessor, can increase the single-thread performance of applications by up to 40 percent. Alternatively, scouting is a technique that makes the on-chip caches appear much larger, performance robustness technique, making up for code tailored for different on-chip cache sizes or even a different number and levels of caches.