PC800 RDRAM in a PC600 System

[Guest]

I am confused. I own a P4 system (an HP 7960) that shipped with 128MB of PC600 RDRAM. It claims to be expandable to 2GB RDRAM. I do want more RAM, although perhaps not 2GB yet. I was advised by the seller that I must find PC600 RAM, and not the faster PC800 RDRAM. Yet, other posts indicate this is not true. So, let me be specific.

1) If I remove the existing PC600 RDRAM, can I replace it with PC800 RDRAM? Will it perform at PC600 or PC800 speeds?

2) If I keep the existing PC600 RDRAM, can I put PC800 RDRAM in the remaining two slots? If so, will it slow down the new RDRAM?

Thank you.

 

[wapaaga]

yes you should be able to becuase i'm pretty sure the only chipset out at that time was the intel which does support pc 800.

you now that you have to buy 2 rdarm moudles to upgrade, both the same size to get it to work. so if you wanted 256 you wqould have to buy 2 128s

<font color=red>Gasoline + Fire</font color=red><font color=green> Can be a lot of fun</font color=green>

 

[Raystonn]

Ok, here is the scoop. Your motherboard/BIOS control how fast the system attempts to access your RDRAM. The RDRAM must be able to support the speed at which you clock it. You can place PC800 modules in your system (2 at a time of equal size, 1 per channel) and they will be backward compatible to PC600 if your system runs the memory at those speeds. If you want to run your system at full PC800 speeds (highly recommended) then you will have to ensure that your motherboard/BIOS supports this. It most likely does. You just need to find the BIOS option that controls the speed of the RDRAM. If you have the ability to switch it to PC800 speeds (400MHz RDRAM bus instead of 300MHz) then this is great. You should then ditch/sell/giveaway your PC600 sticks (you likely have two 64MB sticks, 1 per channel) and grab two 128MB PC800 sticks.

-Raystonn


= The views stated herein are my personal views, and not necessarily the views of my employer. =

 

[Guest]

Thank you. This reply was perfect, timely, and complete.

FYI -- The documentation says that the system supports PC600 or PC800 chips. (I would like to add emphasis on the "or".) And, the BIOS says RAM speed is AUTO. So, I will get the new chips!

Thank you.