> Hyperthread may not make as much difference as i remember, newer cpu may have > lessoned any penalties for non multithreaded apps.
My original question was why a Haswell Pentium with 2 cores and 3M of cache was occasionally slightly faster than a Haswell i7 with 4 cores and 6M of cache. Running on otherwise identical hardware. I literally pulled the Pentium CPU out of the machine and replaced it with the i7 so everything else is identical. I expected the i7 would be equal or faster in every case but that's not what happened.
It was suggested that the difference might have been caused by hyperthreading on the i7 so I disabled hyperthreading and ran some new benchmarks.
Here's the Pentium G3258 compared to the i7-4790K with hyperthreading disabled. The games in pink are the ones that are still slower on the i7 for whatever reason. The games in green are ones that take advantage of the extra cores on the i7...
Also for reference, here's the i7-4790K compared against itself with and without hyperthreading. Games in pink are slower with hyperthreading off. Games in green are faster with hyperthreading off. Out of the 33 games tested, 14 were slightly slower and 19 were slightly faster. So it's basically slightly worse with hyperthreading off but it really doesn't make much difference either way.