FX-9590 and DDR3-2666

[evilgoat666]

Hi I recently had a kit of ram fail on me the specs being as follows:

Corsair Dominator Platinum 32GB DDR3-2400 10-12-12-31 1.65v (CMD32GX3M4A2400C10)

After sending it in to be RMAed Corsair informed me it was discontinued and offered me the below as an alterative:

Corsair Dominator Platinum 32GB DDR3-2666 12-13-13-35 1.65v (CMD32GX3M4A2666C12)

I'm running a ASUS Crosshair V Formula-Z with a FX-9590 would I be able to get this kit to run at its rated speed?
I do realize I'll have to use some crazy D.O.C.P. settings but if anyone has experience of running ram at this speed on an FX any advice would be a great help.

Thanks

[MeanMachine]

Hi evilgoat666 and Welcome to ROG

The CVFZ is officially rated at 1866MHz and anything above is considered an OC. It will depend on the strength of the IMC (Integrated Memory Controller) as to whether you can achieve your rated frequency with 32GB. They may or may not work and not much is gained in FPS anyway. Always best to stick with QVL tested kits imo.
D.O.C.P is not crazy settings. D.O.C.P is used to allow Bios to initially configure CPU ratio and bus parameters in conjunction with the DIMMs you are using.
Your XMP profile can be got in Bios from Tools Menu. Manually key in primary timings and voltage as per the profile and see how you go.

EDIT: The CMD32GX3M4A2666C12 are not listed on the QVL, so you are taking a chance.

[evilgoat666]

MeanMachine wrote:
Hi evilgoat666 and Welcome to ROG

The CVFZ is officially rated at 1866MHz and anything above is considered an OC. It will depend on the strength of the IMC (Integrated Memory Controller) as to whether you can achieve your rated frequency with 32GB. They may or may not work and not much is gained in FPS anyway. Always best to stick with QVL tested kits imo.
D.O.C.P is not crazy settings. D.O.C.P is used to allow Bios to initially configure CPU ratio and bus parameters in conjunction with the DIMMs you are using.
Your XMP profile can be got in Bios from Tools Menu. Manually key in primary timings and voltage as per the profile and see how you go.

EDIT: The CMD32GX3M4A2666C12 are not listed on the QVL, so you are taking a chance.

Hi, I've had a play with the BIOS and to reach 2666Mhz on the RAM using the D.O.C.P. profile for DDR3-2666 the settings are as follows:

CPU Multiplier - x21.5
Base Clock - 223Mhz

This results in a target CPU frequency of 4,794Mhz and a DRAM frequency of 2,676Mhz from that the DRAM multiplier must be running @ x12.
What's crazy is the how high the base clock needs to be boosted to reach it (+23Mhz) AM3 processors seem only to like small tweaks to it.
Also you can load the XMP profile using D.O.C.P. that will set the RAM voltage and timings for you along with settings to run it at or closest to the rated speed.
CMD32GX3M4A2400C10 was not on the QVL but it worked however CMD32GX3M4A2666C12 from the above settings could be tricky.

I was just wondering if anyone has tried using DDR3-2666 anyhow it looks like I would have to experiment I could always run it at 2400 if it doesn't work out.

[evilgoat666]

Ok, so after finally taking delivery of the 32GB 2666 kit from corsair (CMD32GX3M4A2666C12) that was shipped from Taiwan I've done some testing.
Loading the XMP profile resulted in only 24/16GB being detected despite the BIOS reporting all four sticks with the same result after experimenting with speeds down to 2500~.
Speeds of 2500 down to 2200 resulted in the full 32GB and were able to boot to the desktop but were unstable.
I finally hit the sweet spot at 2133 using timings of 11-13-13-32-46 which was rock steady when tested for 4 hours using Prime95.



I'll try doing some more testing to see if I can get it stable at 2400 with different timings when I get time.