If the memory controller is having a problem getting the correct voltage or there are conflicts in the sticks, all kinds of crazy things can happen. You should be able to run 4 gigs at 1066 but i am unsure about the reapers. For the reapers to run at full specs they need 2.1v applied. most of the time the board can provide this but due to the not tuning capabilities of the bios any other ram tweeks are out of the question.
You can try other mfrs of ram if you are looking for the 1066 speed.
Well, I'm starting to wonder if I really need the 1066 speed. The motherboard's FSB is 800, so no matter how fast the memory responds, the motherboard sets the limit, doesn't it? However, Dell shipped this system with memory at 1066MHz, so there should be some advantage to this. Of course, if I only jeopardize my system integrity by using EPP, then I’ll better stay away from it. Somebody in another thread said that 1066 will only be of advantage if you overclock the FSB of the motherboard. If that’s true, then I don’t understand why Dell configured their systems that way. Another one even claimed that a 720 system would perform better at 800MHz vs 1066.
Anyway, do you think I should get the Dominator sticks rather than the Reapers?
The key to running at 1066 on these systems you need ram that is EPP/SLI ready, and the max voltage is 2.1v when in EPP/SLI mode. Any more and the memory will not work at 1066.
What really happens is the memory becomes over clocked when in EPP/SLI mode so an 800mhz base memory with epp/sli will over clock to 1066. And the acutal FSB of the board is 1066mhz
Dell did overclock systems with certain cpu's in them so the ram had to be capable of being overclock with just a voltage change setting as there are noibios settingss
So when I turn on EPP in the BIOS, I'm overclocking the FSB of the MOTHERBOARD to 1066MHz? I didn't realize that. The memory (both PC2-8500 Dominators and Reapers) are designed to work at 1066MHz, so no overclocking needed here.
You have a 720 yourself and you are using 4 x 1GB, Why didn't you want to go with the 1066MHz FSB speed? Any particular reason?