RAM compatibility ???

[Vivek.28]

HI !
I have a Mercury PI945GZD mobo with C2D E4400 & 512 MB 533mhz ram installed on it. I want to upgrade my RAM by 1gb by adding another stick of 667mhz. When I viewed the online manual of the mobo (http://www.mercury-pc.com/product-de...productid=718#) at the mercury website then it shows that my mobo supports on ram upto 533 mhz.....

now the prob is that when I open the BIOS settings of my sys & look at the manual frequency settings than it shows support for 400, 533 & 667 as well (surprisingly !!).....

should I go wid the mfg manual or wid the BIOS....?? I m very confused....
even if the mobo doesn't support 667 even then can I run 1gb 667 wid 512mb 533 RAM....??

Please help me....also give other possible alt soln....

[Xccentricity]

If the mobo doesn't support 667MHz then the speed of the RAM will automatically be reduced to 533MHz, I'm not very sure about this, lets see if anyone backs this up,

And did you update your BIOS?

[dheeraj_kumar]

Why dont you use CPU-Z to check the speed of the memory? then you can know what speed its running in.