Worried about QPI/DRAM Voltage With P6X58D Premium and F3-12800CL9T-12GBSR2

[Cosmogeek]

I installed the F3-12800CL9T-12GBSR2 memory (3x4GB, DDR3, 1.25V, CL9-9-9-24) onto my ASUS P6X58D Premium MB using the X.M.P. settings. Everything is working fine. I ran MemTest86+ overnight without error. My concern is the QPI/DRAM voltage. The BIOS has QPI/DRAM at 1.4v and highlighted in red, indicating this value is outside of normal operating range. The DRAM voltage is 1.25V. I read that QPI/DRAM should be less than DRAM voltage. I have an i7 960 3.2GHz CPU with nothing overclocked.

Should I be worried about the QPI/DRAM Voltage being highlighted in red in the BIOS?

Did the X.M.P. set this voltage, or was I supposed to adjust it?

If it shouldn't be 1.4 V, what should it be?

Thanks.

[Tradesman]

Generally you want QPI/VTT lower than DRAM voltage which is based on standard DRAM voltage for DDR3 which is 1.5....Low voltage sets have been tested and proven safe with the X58, however I might suggest raising DRAM voltage to about 1.3 or so, which would allow you to prob lower the QPI/VTT a bit (I'm not thrilled about getting into the red either)

[Cosmogeek]

Thanks Tradesman. I will try that.

However, I am a bit baffled. This memory is recommended for my MB on the G.Skill product page for this memory. Yet, it seems to be operating at a QPI/DRAM voltage which could damage my computer. Many people who buy this memory are just going to set it to X.M.P., see that it boots, and move on. They won't know that their computer has now begun a process of destroying itself.

If this memory is recommended for use with my MB, why aren't the recommended settings available? Does everybody who buys this memory, essentially have to go through the the equivalent of an OC experiment to find a safe stable operating point for the memory. The recommendation should have come with the caveat, "Only for overclocking experts. Do not use XMP settings. You will not be able to run this memory at spec. You must figure out the correct settings on your own, as they will not be provided".

My plan of attack will be to lower CPI/DRAM to 1.35, and then start cranking up DRAM Voltage from 1.25 until I pass memtest86+. That will have to wait until the weekend, since I can't bring down this computer during the week. Does this sound like the correct approach to you? Should I shoot for an even lower QPI/DRAM voltage?

Thanks.

[Tradesman]

Enabling XMP telss the BIOS to read information off the SPD of the DRAM (basically what is required for the system to run with the DRAM at it's set specs....but....a lot of things play into this, i.e. if it's on a tested list i.e. GSkill's we don't really know what CPU they used when they tested, nor do we know what BIOS version it was tested at...and that can really play in and have problems, i.e. my ASRock Z77 couldn't even run 32GB with the early BIOSs, after I worked with them we got a version that was good to go with 32GB at high freqs (big problem had been a 255 limit on the tRFC setting), then they had another BIOS upgrade and reinstituted the 255 tRFC limit which meant 32GB sets didn't work again. Also each individual mobo/CPU, PSU, GPU combo can have an effect on what the settings need to be. I've on occasion built anywhere from 6-12 identical systems for clients and more often than not end up with a few differences in the settings used to ensure stability on each or may have say 5 use identical and 1 different.

For the most part people get sets and make their builds with no problems, what you'll primarily see here is people that have had problems and I believe equates to less that 6 percent of GSkill's sales on a daily basis. Of those, many are first time builders or haven't checked with tech savvy friends (or did check and their friends weren't as tech savvy as they thought they were )

[Cosmogeek]

I didn't want ot wait for the weekend, so I dropped the QPI/DRAM voltage down to the highest voltage that is not highlighted in red (1.3xxxV don't remember the exact number), although it is highlighted in yellow. I let it go through the first four tests of a pass of Memtest86+ (not even one full pass, but I won't have time for full testing until this weekend). No errors, and the computer had a pretty stressful day today. So far, so good. I assume that I can bring it down even more, but at least I am out of the danger zone for now.

Thanks for clarifying that it is the MB that chose to set the voltage, not the memory. I still have the DRAM at 1.25V. I assume the memory uses more power than the controller, so in the interest of keeping overall system temperature down, I plan to leave the DRAM at 1.25V and just work on getting QPI/DRAM as low as possible, or at least un-highlighted.

[Tradesman]

That works, DRAM doesn't really raise temps much, and 1.5 is the 'basic' standard for DRAM...IMO most of this moving and trying low voltage DRAM is in part in prep for DDR4 which is coming close and will run a lower voltages than DDR3.

Keep us updated.

[Cosmogeek]

I dropped the QPI/DRAM voltage all the way down to 1.2V, which is at the upper end of the specified range (1.1-1.2V I believe), and it has worked flawlessly and tested error free. I have no idea why the MB set the voltage to 1.4 initially. Maybe it is just a bug in the BIOS. Anyway, everything is running completely within specification now so I am happy.

[Tradesman]

Glad to hear it, have fun!