DDR3 at 2.5v???

Hi all.

I've searched this forum quite often during the last few weeks, trying to figure out the right configuration for my new computer. But this is my first message, and I'd be grateful if anybody could help me. I've searched for other threads with the same problems I have, but none found.

This is the configuration I chose:

- Asus P8Z77-V Pro.
- Intel i7 3770k.
- 4x4Gb Corsair Vengeande Red 1866MHz (CMZ16GX3M4X1866C9R).
- Gigabyte GTX 670 OC.
- Crucial M4 128Gb.
- Seagate Barracuda 3Tb.

I built the computer last weekend and had some issues with, apparently, the memory. BSOD, random errors while reading files, etc. Tests with Memtest86 indicate one good stick, one bad stick, and two that only fail when accompanied by the one that's OK (?).

But what really puzzles me is the fact that the BIOS shows very high DRAM voltage readings, between 2.4v and 2.5v. If I select the XMP mode in the BIOS, the sticks are correctly recognised (frequency, timing and voltages), but they remain at almost 2.5v. Trying to set the voltages manually is useless - the BIOS just ignores my inputs. HWiNFO64 shows the same voltages high values as the BIOS. CPU (1.092v while in BIOS) and VCCSA (0.925v) seem OK, but PLL (2.775v) and PCH (2.012v) seem also way too high.

I'm no expert, but as far as I know 1.5v is a normal value for DDR3 @1866, and voltages as high as 1.55 or 1.60 are only recommended for overclocking. What can be the reason my BIOS sets (or maybe just reads?) such high values?

I'm having other issues with the MOBO (false and unstable CPU FAN readings, too low CPU temperature reading) but that with the voltage is the most worrying one.

I've already placed an question at Asus' Support but still waiting for a reply.

Thank you very much in advance,
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  1. You're assuming 'HWiNFO64' is even remotely correct. I would use either AIDA64 Extreme or (try though I don't like) ASUS AI Suite II. As far as the DRAM Voltage, it depends upon the Frequency, Density and CAS Timings of the set. The newer IB kits are often 1.60v~1.65v which concerns me less than the CPUVTT/VCCSA Voltages that do the damage.

    I would suggest that you F5 (Load Optimized) and set the AI Overclock Tuner -> XMP then F10 to save and exit = Yes.

    My best guess is the 'HWiNFO64' is crap and is reading erroneous data.
  2. Hi Jaquith,

    Thanks for your reply. AIDA64 shows the same high values. Also 2.0v for the South Bridge, which I don't know if it's ok.

    I've tried what you said, with no result.

    The computer is completely stable and has already run for quite a few hours now since I built it, mostly until I realized those ugly voltages. Shouldn't the RAM already be fried out if those 2,5v were real? Could it be that I've got a problem with the readings, rather than with the regulation? Do you think this and the other problems (false CPU Fan and Temperature reading) may be related to each other?

  3. In reviewing the supported chipsets - http://www.hwinfo.com/index.html there's no listing yet for the Z77 on (duh me) either Application.

    AIDA64 Beta - (search) http://www.aida64.com/search/node/Z77 ; (Try) the latest Beta (2.50.2003) - http://www.aida64.com/downloads (Example) forum discussion - http://forums.aida64.com/index.php?/topic/773-ivy-bridgez77-temps-asus-p8z77-deluxe-core-i7-3770k/

    Also per KB (The temperature, voltage or fan rotation values on the Computer / Sensor page are inaccurate. ...)
    "Unfortunately there is no standard for sensor chip registers layout, hence in several cases the registers layout that AIDA64 uses could fail to be accurate."

    My feeling is then and now you discovered two applications with bugs.

    A DRAM Voltage that high, 2.5v, would fry the RAM not to mention the CPU so I am still of the thought "reading erroneous data." Hell no your system would not be stable if that voltage were true.

    IF the ASUS UEFI (BIOS) reading states DRAM 2.5v then RMA the MOBO faster than you can click this page open. Considering the newness of the Z77 I would suggest using AI Suite's Applications and relying on that data.
  4. before you go ram that mb did you install the newest bios updates.the newest updates from asus are for cpu code and rams. the mb may read your ram right after it has the newest bios installed. (1015).
  5. Thanks once again for your replies.

    I forgot to mention it, but flashing the board with the last BIOS was one of the first things I did. I've tried with all three available BIOS - with no result.

    The BIOS, AI, Aida64 and HWInfo all show those absurdly high fan speeds, so it's not just a bug with those programs - not only that at least. The same applies to the RAM voltages, so there definitely seems to be something wrong with the board. Asus' Support has suggested I return it.

    The RAM I've bought is NOT in the vendor list from Asus. Very similar packs with 8 or 32 Gb, but not the 16 pack I've bought. I don't know if that's the reason for the problem with the voltage. I might be able to test it with another module tomorrow, I'll comment the result here if there's interest. Anyway, as there are other problems with the MOBO which have nothing to do with the memory, I'll return it on Monday.

  6. I would agree to exchange the MOBO especially IF the BIOS (UEFI) shows a DRAM Voltage = 2.5v, something is messed-up on the DIGI controller.

    Most Retailers/E-tailers offer 'Cross-Ship' aka 'Expedited RMA' so the downtime is minimal; shipping time or go in personal to exchange.
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