RAM Question

[Not Bman]

I have a EVGA 780i SLI motherboard.

I currently have according to Everest DDR2-667 ram in my system, which is PC2-5400, I know my ram is running at 1066MHz, my mobo according to everest says it supports up to DDR2-800 which is PC2-6400, I believe PC2-6400 is what I actually have in my system, I am getting PC2-8500 ram at 1066Mhz, will I be able to run it?

I have seen many articles about other issues, but they mention they are running pc28500 ram (8gb at that) on the 780i motherboard.

I dont know how to confirm or not confirm this, so I am asking here. And if I can run it (i hope) why would a motherboard state less then what it does.


And here

http://www.evga.com/products/moreInfo.asp?pn=132-CK-NF78-A1

Says up to 1200MHz ram, I am getting confused.

 

[LordOfLA]

Ah the source of the many msn dings is revealed

 

[dreamliner77]

Your ram is actually running at 533 but it comes 1066 (DUAL data rate).

 

[LeeJend]

Limitations on actual RAM speed:

1) The chipset may not be officially rated to handle faster RAM but in some cases it will and the BIOS may allow you to set a speed higher than officially rated for the chipset.

2) The chipset may be one that does not allow you to set the CPU clock and the RAM clock independently. In this case the RAM speed will be some fixed multiple of the CPU clock speed regardless of how fast the RAM is rated.

If your MB forces your RAM to run slower than it can there is not much you can do (new MB or a new CPU who's clock matches faster RAM clock speed). Or you can improve the RAM timings to squeeze a little (very little) more performance out of the memory. The improvement is usually not worth the effort and risk of crashes and data loss.