> That is very interesting. So could I then conclude that Intel is selling their Sandy > Bridge chips at an artificially low clock rate because they don't have any > competition that would force them to sell them closer to their potential speed?
Well, I'll freely admit MAME is a special case here that makes SNB look better than it might in a more general sense. There are very few other workloads you can impose on a PC in which per-clock single-threaded performance is of paramount importance nowadays.
> Meaning that if AMD was more competitive, Intel could just as easily sell these chips > for the current price at higher clock rates as they can sell them now for the same > price at lower clock rates?
Yes. IMO they could easily sell SNB at a stock clock of 4+ GHz without blowing out the thermal envelope. And actually the current pricing on SNB is quite good historically - for ~$300 you can get a 2600K that can blow the doors off every $999 Extreme Edition Intel's ever produced.
> If so, it only underscores the value of AMD in the x86 marketplace. We can all just > pray that Bulldozer is competitive.
Bulldozer is reportedly optimized for multi-threaded workloads at the specific expense of single-threaded instructions per clock. That's totally viable for a lot of workloads now and it'll probably review and compete well (especially in servers), but it's not great for MAME.
> Or - is there another alternative - which is that in order to achieve these 'insane' > Sandy Bridge overclocks you have to use either a very expensive cooling solution, or > a very loud one, or both, which thus prevents Intel from selling these things at such > high clock rates?
I'm using a ~$50 air cooler to run 1 GHz over stock, and it's got 2 large slow fans in a push-pull configuration, so it's no louder than the stock Intel cooler. Remember, Intel was shipping the Prescott P4s about 6 years ago, and those things idled very hot, let alone under load. If they brought back that cooler they'd be all set for stock-rated 4+ GHz parts I think.