4 ms·
Ridiculous parallelism. A POWER8 chip has 12 cores, and each core can handle 8 threads. As a result, these chips can keep the pipeline pretty much always full,
by Sanddancer 13y ago
Ridiculous parallelism. A POWER8 chip has 12 cores, and each core can handle 8 threads. As a result, these chips can keep the pipeline pretty much always full, and provide massive performance boosts to things like database servers.
- joosters 13y agoSun's Niagara line of processors had similar numbers of threads (64/128), but they often had lacklustre performance. With this amount of parallelism, it becomes very difficult to keep all the threads busy, even for highly scalable programs. You'd get hit by all kinds of problems, like blockages due to memory throughput, or shared resources (IIRC the Niagara threads shared FPUs and other processing blocks, so to get them all running 100% of the time you'd have to manage the workload of your tasks insanely carefully) On top of that, so much stuff just doesn't scale well. On the early Niagaras, even ssh-ing into the machine was noticeably slow. Oh? your crypto doesn't use all 64 threads? Hard luck!