After making sure you're using the correct basic algorithms, cache optimization is probably the one major thing that's really worth thinking about. Even with h

After making sure you're using the correct basic algorithms, cache optimization is probably the one major thing that's really worth thinking about. Even with hyperthreading and all the other fancy tricks that modern CPUs have, it's still a huge deal. I learned about all this stuff in general terms at university years ago, but it didn't really click until recently that even when the CPU is at 100%, it's very very often stuck waiting for a memory read to complete.