ASUS P7P55D EVO memory recommendation

[FP]

I am having a helluva time figuring out what kind of memory to buy for this board. I am not going to O/C at all but almost none of the memory listed in their QVL doc makes sense. They list a whole bunch of 3 and 6GB 3-stick sets but this is a 1156 board... wtf? There are only 9 4GB 2-stick options out of about 40 options @ 1600MHz.

According to the memory QVL:

"Due to Intel spec definition, X.M.P. DIMMs and DDR3-1600 are supported for one DIMM per channel only."

Ummm... So does this mean if I buy DDR3-1600 sticks I can only use 1 in each channel? If so, can I simply down-clock the sticks to 1333 and run 4 sticks in dual channel?

and

"According to Intel CPU spec, CPUs with a core frequency of 2.66G support the maximum DIMM frequency of up to DDR3-1333. To use DIMMs of a higher frequency with a 2.66G CPU, enable the DRAM O.C. Profile feature in BIOS."

Again, does this mean DDR3-1600 sticks down-clocked to 1333 won't need the OC profile turned on?

Thanks for any info...

 

[cmdrdredd]

I am having a helluva time figuring out what kind of memory to buy for this board. I am not going to O/C at all but almost none of the memory listed in their QVL doc makes sense. They list a whole bunch of 3 and 6GB 3-stick sets but this is a 1156 board... wtf? There are only 9 4GB 2-stick options out of about 40 options @ 1600MHz.

According to the memory QVL:

"Due to Intel spec definition, X.M.P. DIMMs and DDR3-1600 are supported for one DIMM per channel only."

Ummm... So does this mean if I buy DDR3-1600 sticks I can only use 1 in each channel? If so, can I simply down-clock the sticks to 1333 and run 4 sticks in dual channel?

and

"According to Intel CPU spec, CPUs with a core frequency of 2.66G support the maximum DIMM frequency of up to DDR3-1333. To use DIMMs of a higher frequency with a 2.66G CPU, enable the DRAM O.C. Profile feature in BIOS."

Again, does this mean DDR3-1600 sticks down-clocked to 1333 won't need the OC profile turned on?

Thanks for any info...

Supported does not mean "it doesn't work". You will probably have to fidget with voltages etc.

 

[n7]

Unless you increase BCLK, you've got DDR3-1333 as your maximum speed available.

Yes, you can just downclock, & perhaps even tighten the timings also.

 

[Ben90]

It basically means that the memory controller will default to the fastest speed up to ddr-1333. If X.M.P. is enabled, and the ram can handle it, the controller will go up to ddr-1600, but drop down to single channel (and i believe that some of the memory will not be mapped, but im not 100% sure)

I have no idea why intel decided to include ddr-1600 at all because dual channel 1333 is faster than single channel 1600, except in extremely rare cases where an app is cache starved, but doesn't need raw bandwidth

Basically get ram thats ddr3-1333 or faster, has a voltage of 1.5 or less, and whatever capacity you want (and if your looking to maximize performance get the lowest CAS available, but there is very little real world benefit from a lower CAS, aside from benchmarks). And Don't touch X.M.P.

 

[Yellowbeard]

I suggest you take a look at the website for whatever memory you want to use. They should have data on what kits have been approved for your board.

 

[Yellowbeard]

And Don't touch X.M.P.

FYI, the controller does not revert to single channel when enabling XMP under any circumstances nor does it revert to single channel at 1600. The memory controller determines its mode from the physical configuration of the memory, ie what slots the modules are in.

Why do you say don't touch XMP?