i bought my tower about 3years ago now and im not well up on pc specsso ill tell you all i knowintell pentium 4 2.9gig(ish)nvidia fx 5500(yep i know)1 gig rami was reading a thread about using one core if you have a duel core machine,im assuming due to ignorence that dou core i quite newmy question is how do i know if my system is single core or notthe reason i ask is when i went into my task maneger and set affinity(i think) it had cpu 0 and cpu 1 both checked,does this mean i have two cores it cant be true,surelyyes im quite thickregards paul

If you bought your system three years ago then you most definately do not have a true dual core processor. Judging by the fact that your task manager shows two cores in operation makes it highly likely that your P4 is of a variety known as hyperthreading (HT). I'm sure many others here can explain HT versus dual core much better than I, but the essence is that HT trys to make a single core perform as efficently as two by utilising otherwise idle circuitry on the processor whereas dual core actually is two separate, fully functional cores. A simple analogy that I can think of is two mechanics in a workshop working separately changing tires on vehicle. With HT, they would both be sharing the same tools, which works fine when they happen to be using different tools, but one of them has to stop what they are doing when they both need the same tool. Dual core means that both mechanics have their own tool sets, so there is never a problem of one having to wait for the other.So, in short you have what is known as the "poor mans dual core" in that sometimes it will be lucky and process more than what a single core could do, but not nearly as much as a true dual core processor.Gary

garythanksfor your replypaul

Hyperthreading works pretty well IF the application is written to take advantage of it. Trouble is not many are.Don't know about MS FS.

Sounds as if you have hyperthreading...Dual core (and they can both allow hyperthreading) means that twoseparate chips are present and can do two things. Theoretically youcan get up to 200% over a single core, though not usually likely.FS9 is not explicitly multi-core but does scenery as a separate thread from the flying, so you can get up to about 180% in someunique situations, though generally 130% is typical over a singlecore. FSX pre patch - Aces took out the separate thread for scenery tosolve the bluries, but this meant that fps took a bad hit. FSX did notutilise multi-core well, and with the demo I could not get muchabove 110%FSX + SP1 has been specifically threaded to allows any number (currentlimit is 32 in windows), of core to run. Much of this is scenery which results in bluries when users don't match parameters properlywith FSB speeds and memory speeds and GPU memory etc. FSX canutilise a large proportion of multi-core machines - though I havenot done explicit timings on this like FS9hyperthreading allows a single process to work on multiple things(it has to work on one thing at once, but is "time sliced"so you think it does lots of things). How does this help with FS9/X.Well, IO to memory/disk/GPU can block the processor - so you get astutter. Also, latest processor micro-code can have "look-ahead"within the instructions to work out what to do next and hyperthreadedCPU can help with this. Anyway, hyperthreaded CPU can help withthis IO blocking and the processor can work past the IO blockwith the "other" thread. Hyperthreaded CPU can therefore NOT giveyou more than 100% of 1 CPU, but can prevent drops in % CPU dueto IO blocking.Hope this helps...Tom

thanks for the replys guysis there anything i should do with this hyperthreading to increace performance or will it be taking care of its self?paul