3 ms·
If you're doing lots of reads, the L1 and L2 caches help things a lot. They are an order of magnitude faster than main memory access, so as you add more cores,
by karterk 14y ago
If you're doing lots of reads, the L1 and L2 caches help things a lot. They are an order of magnitude faster than main memory access, so as you add more cores, this helps in the overall performance.
- merijnv 14y agoThe grandparent is right, the problem with multi-core is the L1 and L2 bottlenecking operations. The cache consistency protocols used to keep memory consistent between cores introduce more and more overhead as you introduce more cores. This is one of the reasons Intel's experimental SCC had no cache consistency. Eliminating cache consistency in multi core chips is the simplest way to eliminate the cache bottleneck.
- marshray 14y agoI believe Larrabee was promising full coherency across all core caches. Of course, many of us could have told them that that wasn't going to work, but they didn't ask us now did they? :-)