Guys,Yet another question about the optimum choice I am trying to make for a new rig. I've been browsing this forum and lots of others, reading with lots of interests posters, googling, asking advises to my retailer prior to my order etc, and found lots of informations but I still cant figure. Especially because many posts know deals with rigs for FSX.I am an fs9 user and dont plan on FSX anytime soon. I'm aiming at an Q9550 which FSB is 1333. I run WinXP Home 32bit SP2.I came to the conclusion that some DDR2 667 PC5300 would make it for 1:1 ratio (no OC for me), especially for a non 64bit OS, yet I still doubt. I know XP32 wont make a full use of all 2*2Gb I want to install,and I want to be sure that with 4Gb I wont fall in memory problems with WinXP32.The motherboard I picked is an Asus P5Q-C which support also the DDR3. I was told the Q9550 and the iP45 mb chip turns around DDR2 better than DDR3. What'd happen if I choose some DDR3 PC10600 or some DDR2 PC8500? :( Thanks in advance.

Those hybrid mobos aren't the best solution due to the limitations they impose. Namely, you can't use DDR2 and DDR3 simultaneously so you can only use 2 DIMMs at a time, basically limiting you to 4GB RAM. Perhaps not a limitation for now, but who knows how much RAM you'll want in a year or two. Also, the upper bound on the memory speed is usually lower with these boards, meaning you can't use RAM that's as fast as you might be able to on a board that only supports one memory technology. Given the recent trends in memory pricing, I'd say go for a DDR3 board. DDR2 is still pretty cheap but the higher performance stuff has actually increased in price as of late. May as well get the faster stuff and perhaps be able to re-use it in a future build or at least have the ability to purchase more RAM sometime later if desired.

Thanks MaxC,Of course I didnt plan to mix DDR2 and DDR3, but the fact that those hybrids mobos could induce limitations makes sense, although I've always thought that what dealt with the RAM was nothing but the onboard chipset, namely the Intel P45. And the DDR3 only mobo I found (Asus P5Q3) with only DDR3 supported, has got the same iP45 chip mounted.Now how about the choice between all the different DDR3 available? PC3 8500? PC3 10600? PC3 12800? for a CPU (iQ9550) which FSB is 1333.I see on your spec maxC that you're an FSX user, but about fs9, are you still positive that a [email protected] would run fs9 better (better=smoothness, graphics sharpness and stutterless-wise, not only FPS) than a [email protected]?

FS9 is not multi-thread aware. It will run better on a higher clocked dual core than a lower clocked quad core.

If you want future proof, and the ability to look into FSX in the future as well (even though you mention not wishing to change...) you want to go for the fastest processor you can afford. I would look at the current i7 series and pair it with DDR3, 6Gb for a 64bit OS... Get adequate cooling for the processor and chipset/mosfets and you can overclock the i7s nicely, and FS9 will run faster than you have seen...I wouldn't ever have believed myself saying this, but I can get a visual smoothness on my current setup (see sig line) in FSX that matches FS9's with a better overall visual appeal of the ground, thanks to GEX... major built up areas are a little heavy under FSX mind, though I am not running the most optimised system for FSX...I currently use FSX for GA and the JS41, and FS9 for my ATPL type simulation... and am a generally happy puppy in both worlds...Andrew

Okay thank you guys, I must admit I am still so unsure about what to choose as a CPU. Might well be the duo [email protected] rather then the quad [email protected], what about the choice for the RAM? I will follow MaxC adise about the no-hybrid mobo, and get some DDR2 only. Shall I go for some PC-8500 or PC-5300, for an 1333 FSB ?