I have a happy A8R32 MVP mobo with 2 x 1GB GSkill DDR SDRAM installed. I'm considering adding more SDRAM into the empty 2 RAM slots, but I know the manual says when you fully populate the slots with double-sided SDRAM modules, the bus speed is cut from 400 MHz to 333 MHz. Considering that I often am NOT using enough RAM to force me into the disk SWAP file, any slowing down of the RAM makes such a move worse that useless! I understand this automatic adjustment of the BIOS has to do with ability to manage signal levels in the address and data bus lines for the SDRAM.
Anyone know if there is a way to run the RAM at the full 400 MHz speed when all four slots are filled? Again, it's an Asus A8R32 MVP mobo, and the CPU is a Athlon 64 x2 4400+ (the low-wattage 89 W version). Maybe an improvement included in a BIOS update? Or, using manual overclocking settings to force the bus speed?
Dealt with this before. The limitation is not the motherboard or RAM, its the memory controller in the cpu. There was no way for me to go past the 333mhz mark either - I tried upping the bus and hoping the ram divider would compensate, but it didn't.
Athlon 64 x2 4400+ 89 W version was able to run 4 x 1GB Samsung K4H510838D-UCCC at 400 MHz on Asus A8R32 MVP with BIOS "Memclock Value" manually set at 200 MHz (400 MHz for DDR is 200 MHz clock) without further adjusting. Memory 333 MHz will not be slower if working at lower latency (CAS=2), what may be possible at lower clock (333). Lower clock for 4 modules seems to be BIOS default auto setting preventing transmission errors and instability. Irrespective of the number of modules and their clock, SATA 3 or 4 in A8R32 MVP probably will not always work concurrently with secondary IDE master or slave.