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ASUS P7P55D & i7 875K and Memory speed ?

  • Asus
  • Intel i7
  • CPUs
  • Motherboards
  • Memory
Last response: in Motherboards
November 29, 2010 1:00:33 AM

Hi Guys

I am putting together a new system. I seem to find conflicting info on the correct memory chips and speed for the motherboard and CPU i have picked.

I am getting a ASUS P7P55D-E Deluxe motherboard and an i7 875K CPU.

I was going to order 16GB of dual channel mem DDR3 1600mHz but the CPU spec at intel don't list this speed for this CPU, it shows 1066/1333 only. See link below

What speed should i get.
Is there any good reason to get this faster memory with this motherboard/CPU combo ? or should i just get the 1333mHz memory.

Also i read in the motherboard manual.
"According to Intel spec definition, DDR3 1600 is supported for one DIMM per channel only. ASUS exclusively provides two DDR3-1600 DIMM support for each memory channel."
What dose this mean ?, if i used DDR3-1600 memory will it only be in single channel mode ?

It seems all this memory is out of stock so i have some time to pick the correct ones for this system.

Thanks, Rainey

More about : asus p7p55d 875k memory speed

Best solution

a b Ĉ ASUS
a b V Motherboard
November 29, 2010 6:28:21 AM

DDR3-1333 MHz is the native frequency for your motherboard and for Intel i5 and i7-8xxx cpu. Therefore, no other setting changes in BIOS are necessary.

But your cpu ( Intel i7-8xxx series only ) is also compliant with DDR3-1600 MHz with no setting changes in BIOS. Therefore, you can get DDR3-1600 MHz RAM sticks.

The important thing is, DRAM voltage should preferably be 1.5 V and not greater than 1.65 V for i5 and i7-8xxx cpu.

If your DRAM is X.M.P. capable and you enable this setting in BIOS, then the motherboard manual says you should use one DDR3-1600 MHz RAM stick per channel only. That means, you can install 4 GB + 4 GB RAM sticks only, a total of 8 GB. This will still be dual-channel ( not single channel ) provided that you install one DIMM in A1 ( blue ) slot and one DIMM in B1 ( black ) slot.

If you do not enable X.M.P. in BIOS ( and you do not need to enable that for i7-8xxx cpu ), then this restriction should not hold true for you.

The important thing to remember is, A1 slot is not the slot ( blue ) closest to cpu socket. It is the slot second closest to cpu.
November 29, 2010 5:30:58 PM

Thanks suat

That answers my questions.

I will be using 16GB so the X.M.P setting will not apply.
I guess if i really wanted to Over Clock this thing and that includes the memory i could spend more for the memory but i don't think i will be doing that at least not the memory anyways.

I seem to have read i would need the best top notch memory to over clock it and have it work good and you get a very small gain doing so. Not sure it is worth it for the little OC i would be doing.

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December 1, 2010 11:06:13 PM

I have almost the same setup as you, and to be honest I don't know why you need 16gb of RAM. I use 6gb of OCZ RAM with a low latency time and it is way more than enough.
December 2, 2010 5:30:33 AM

th0mas87 said:
I have almost the same setup as you, and to be honest I don't know why you need 16gb of RAM. I use 6gb of OCZ RAM with a low latency time and it is way more than enough.

I will also be running Virtual machines. So the extra memory is so i can have four or five PC running at the same time all on the one box.

i ended up getting the 1600mHz memory and changed the board to the P7P55D-e PRO.
December 9, 2010 6:09:47 AM

Best answer selected by Rainey.
a b Ĉ ASUS
a b V Motherboard
December 9, 2010 7:20:36 AM

I assume you have your rig up and running with 16 GB memory. Enjoy.
a b Ĉ ASUS
a b à CPUs
a c 136 V Motherboard
a b } Memory
December 9, 2010 12:02:49 PM

This topic has been closed by Maziar