During some Problem determination tasks with Microsoft to sort out an issue with FSX I started thinking deeply about how efficient dual processors were.

It started when i noticed FSX was using 98% of CPU0, and only about 6% of CPU1. MS suggested playing wit the affinity settings in taskmanager. This prompted me to try a similar test with games that DO use both cpu;s - like QUAKE4.

Even under the heaviest stress, quake4 never gets either cpu above 65%. thet is - both cpus are showing 65% usage simultaneously.

I tried lots of other games, and none of them got the combined cpus above 65%.

My question then, is, is there a high watermark that dual processors cannoy get above? is there some kind of performance drain on dual processors as they share out the workload, syncing and choreographing themselves?

I have a AMD x2 5000+
65% of 5000 is 3250 - so is my 5000 x2 equivalent to a 3300 single core?

Try encoding some video tops my CPU out at %100 and %100 no problem. Games are the worst programs for dual cpus. Untill they gets coded right it won't max them out. The longer you have that CPU the better it will get.

hmm

ok - thanks for that

in fact i heard someone that video rendering is one of the few things the lower ghz quad cores got over the higher ghz dual cores 

Games aren't nearly as multi threaded as workstation based uses. Video editing, 3d modeling, photoshop, encoding, etc...Are all multithreaded and take advantage of the extra cores. But games unfortunately aren't multithreaded...It's taking a turn for it though, but it'll take a bit of time before they can fully utilize multipler cores effectively.