I want to upgrade my RAM.But can't identify speed is running

[webdesignsguru]

Hello,

I am posting the first time, in Digit forum, though I am a regular reader of the magazine. The problem that I am having is that I want to upgrade my RAM. At present I have 1GB DDR2 RAM, but dont know the frequency or the speed of it. I want to include another 2GB RAM module in my system, so that I have a total RAM of 3GB. But I am stuck with the so called speed. I have installed the CPU-Z and ran it, but can't understand it. I went to my local dealer and showed him the 1GB RAM module, and he told its 667Mhz, but I have some doubt on him. Also my motherboard is Asus P5GC-MX, so if I keep my older DDR2 1GB module in 1 slot and insert a new 2GB DDR2 module in another, will it run alright or there will be any problem? I saw in some site that if you insert 1GB in 1 slot, you must use 1GB module in another slot for stable performance, is it true? Anyways, I know Digit forum, has got some real good hardware champs, who can help me in this issue. I have posted the screenshots of the CPU-Z below for your information, so that you can tell me the accurate answers.
Oh my processor is Core 2 Duo E4500@2.20 Ghz (Codename: Conroe), Socket LGA 775.

Motherboard Information
*img52.imageshack.us/img52/5862/motherboardinfo.th.jpg

Memory Information 1st Page
*img718.imageshack.us/img718/196/memoryinfo1.th.jpg

Memory Information 2nd Page
*img804.imageshack.us/img804/8862/memoryinfo2.th.jpg

Waiting for your answers guys.

Bye.

 

[coderunknown]

speed is 533Mhz. though 667Mhz is supported but maybe you need to manually set ram at that speed. grab DDR2 800Mhz ram as lower clocked DDR2 ram are hard to find and will cost you same. though the new ram will clock down to 533Mhz once you install it along with old ram. check flipkart for pricing.