RAM for 3930k & X79

MightyMatt

Gawd
Joined
Dec 23, 2006
Messages
532
I wanted to ask the experts what they'd recommend for RAM for a general gaming and home desktop. My to-be rig will have an Intel i7-3930k processor and an Asus P9X79 WS motherboard. I have G.Skill RipJawsZ 16GB (4gb x 4) DDR3-2133, PC3-17000, CL9-11-10-28, 1.65v, Model # F3-17000CL9Q-16GBZH, but haven't gotten all the components to try everything together, yet.

Does the DDR3 2133 RAM run as DDR3 1600, unless you tune it to 2133 (tested speed?)? I'm not interested in overclocking the rig, especially right away, and want to be sure the RAM should be plug and go with the CPU and Mobo. Will this be the case, or do I need to consider other RAM?

For future reference, what is the best RAM this setup could hold?

Thank you for your time and knowledge! This is an upgrade to my current rig in my sig ;)
 

cyclone3d

[H]F Junkie
Joined
Aug 16, 2004
Messages
14,648
It will run at 1600 by default unless you enable the XMP profile or manually set it up.

The "best/fastest" RAM that will work in the system really depends on how good the IMC on the CPU is.
 

mrluckypants96

Limp Gawd
Joined
Oct 6, 2015
Messages
431
Can you please explain the IMC with this chip in mind? I'm looking to just stay at 1600 to start.

I did some Internet digging and thought this RAM would be the best 32GB Quad Channel RAM at 1600: Crucial Ballistix Tactical Low Profile 32GB Kit (8GBx4) DDR3-1600

Can the memory voltage be lower than 1.5, or does it need to be what the CPU is?

The IMC, or "Integrated Memory Controller" is the part of the CPU that controls the RAM. It tells the RAM what frequency, timings, and voltage to run, as well as controlling data transfer to and from the DIMMs. Any frequency RAM kit (within reason) should work, so a 1600MHz kit and a 2133MHz kit should both be easy to set up, but a 3200MHz kit would be hit-and-miss, due to the extreme frequencies of the RAM stressing the memory controller. Any 4x4GB or 4x8GB RAM kit can be run as quad-channel, since memory channels are done within the processor, and have nothing to do with the memory sticks themselves (well, they still need to match, and there has to be 4 of them to run quad-channel). Memory voltage is independent to the CPU voltage, and DDR3 RAM kits can run anywhere from 1.2V for low-power biased kits to 1.65V for higher performance kits.

To run any memory kit at it's rated speed, you'll want to go into the BIOS and enable XMP (eXtreme Memory Profiles), which automatically sets the RAM to the frequencies, timings, and voltages specified by the RAM kit, no special tuning required.
 

MightyMatt

Gawd
Joined
Dec 23, 2006
Messages
532
Thanks so much for the info man! I guess my last question would be will RAM sticks advertised as 2133 (OC) timings default to that under XMP? If that means voltage above 1.5V, like 1.65V will that be bad for the CPU?
 

SomeGuy133

2[H]4U
Joined
Apr 12, 2015
Messages
3,447
It will run at 1600 by default unless you enable the XMP profile or manually set it up.

The "best/fastest" RAM that will work in the system really depends on how good the IMC on the CPU is.
yep and he already has good RAM. He can only get a little better anyways but his choice was a solid one overall.
 

mrluckypants96

Limp Gawd
Joined
Oct 6, 2015
Messages
431
Thanks so much for the info man! I guess my last question would be will RAM sticks advertised as 2133 (OC) timings default to that under XMP? If that means voltage above 1.5V, like 1.65V will that be bad for the CPU?

NP :)

RAM with speeds over 1600MHz will run at 1600MHz until you enable XMP, at which point they will run at their advertised speeds. Voltages higher than 1.5V are fine, the IMC can take some overvoltage just fine.
 

SomeGuy133

2[H]4U
Joined
Apr 12, 2015
Messages
3,447
NP :)

RAM with speeds over 1600MHz will run at 1600MHz until you enable XMP, at which point they will run at their advertised speeds. Voltages higher than 1.5V are fine, the IMC can take some overvoltage just fine.
isn't IMC on SB/IB 1.65V already?

Also if XMP has issues just manually set the setting in MB.
 

SomeGuy133

2[H]4U
Joined
Apr 12, 2015
Messages
3,447
oh your right. I thought it was 1.65v but thats an XMP OV.

DDR4 i thought was 1.35V but that is also XMP OV. DDR4 is 1.2v.

I was mistaken thanks!

so used to seeing 1.65v and 1.23v i thought that was standard but thats actually an OV from the standard :D
 
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