MP 1,1-5,1 1333 MHz or 1066 MHz ?!?!

[h9826790]

well recently I dropped my memory from 128gb to 96gb and got a 25% boost in benched performance. The AboutThisMac info was showing all 8 DIMM's as running at 1333mhz, but apparently...pulling out the DIMM's from slots 4 and 8, which are shared dual channel....increase benchmark score by 25%. Were they causing things to clock down, even though not displayed as clocked down in AboutThisMac? I don't know, but that is why I'm asking these questions just to understand and make sure I'm not missing any other significant opportunities for improvement.

That reported clock speed is correct. Use slot 4/8 or not won't affect that reported speed accuracy.

You get 25% boost in benchmark because benchmark intentionally disable cache to measure pure memory performance.

In real world, no software will do that, disable cache will only degrade performance. Therefore, in real world, use slot 4/8 to get more avail RAM usually help real world workflow performance more.

Benchmark aim at measure a specific part's performance. The overall computer performance is another issue.

Benchmark can't benefit from having that extra 32GB memory, but OS and real working software can.

Of course, it's still case by case. However, the real world performance difference usually within 3%. For most normal users, it isn't that significant.