Yea, I am currently compililing a 64 version and a 64 duel core version to do just that... I was hoping someone had tried before.
Well like I said, its generally about a 5% increase in speed. But mame can vary a bunch from driver to driver, so for any particular game it could be better or worse.
Yeah, I've heard a few games do get a nice boost, but they're the exception usually. At least as of a few versions ago.
One thing I've been wondering about is
Intel's i7 & i5 "turbo" feature. If all cores are used, the chip runs at the stated speed, but as fewer cores are used, the chip is able to run at faster speeds automatically. For an app like mame, that can use multiple threads/cores, but only to a small boost, would it be better to force using less cores to great a higher turbo?