Extremely strange memory problem (present and detected, but not being used)

My motherboard is ASUSTek Sabertooth Z77

My RAM is 2x 8GB Avexir Core DDR3 1600MHz + 2x 4GB Corsair Vengeance DDR3 2133MHz

My CPU BCLK is overclocked to 105.7MHz, CPU is an Intel Xeon E3 1240

My BIOS reports 16GB installed (2x 8GB Avexir Core).

My OS (Win 7 Pro SP1) reports 16GB installed.

However, CPU-Z can detect all 24GB of RAM present.

What is the problem?

All 4 DIMMs work.

All 4 slots work.

Installed in 8 - 4 - 8 - 4 pattern - 12GB per channel.

Both channels are enabled in BIOS. Even did a reset, nothing changed.

It worked up until I noticed the RAM amount was lower and boot times were longer.

Can someone explain this?
Reply to EquineHero
16 answers Last reply
More about extremely strange memory problem present detected
  1. Probably doesnt like the 2133 ram. Since it doesnt support 2133 ram
    Reply to Paul NZ
  2. Paul NZ said:
    Probably doesnt like the 2133 ram. Since it doesnt support 2133 ram


    That's weird, but it ran fine for about a week. I also put in two sticks of Corsair Vengeance 1600MHz 4GB modules, brand new. Same problem.

    Is my memory controller messed up?
    Reply to EquineHero
  3. MERGED QUESTION
    Question from EquineHero : "Z77 Sabertooth sees all RAM, but doesn't use it"

    EquineHero said:
    Posted before but got minimal support.

    I have a Z77 Sabertooth board. I had 24GB installed fine, was able to fill all of it up.

    Then later last week (around Friday) I noticed I only have 16GB installed, even though all 24GB are present.

    I check CPU-Z, true enough, it sees all of my memory.

    Next I went into the BIOS and checked the SPD tool. Sure enough, the BIOS can see all of the sticks.

    What is the problem? I've reset the BIOS multiple times, swapped out sticks, and even bought new RAM of the same model (Vengeance XMP 2133) lo and behold, nothing works.

    It seems that only 2 DIMMs can be active at any time. I don't get this.


    Should have continued from your previous post
    Reply to Paul NZ
  4. run memtest.org usb autoinstaller and boot from the created bootable USB flash drive

    BIOS up to date on version Version 2104 ?

    Restart windows, to freshly load the system
    Reply to helpstar
  5. helpstar said:
    run memtest.org usb autoinstaller and boot from the created bootable USB flash drive

    BIOS up to date on version Version 2104 ?

    Restart windows, to freshly load the system

    Yeah, BIOS latest.

    Ran Memtest on all of my RAM per module in each slot for an hour. All passed.

    It's not a Windows problem, something is wrong with the motherboard.

    I checked the socket for bent pins, nothing.

    Tried my i5 3470, still problems.
    Reply to EquineHero
  6. if it´s not windows, where do you see the lack of memory? In BIOS?

    Did you run memtest with all RAM installed?

    Speed of the RAM is at 1600MHz and at default BIOS settings?
    Reply to helpstar
  7. helpstar said:
    if it´s not windows, where do you see the lack of memory? In BIOS?

    Did you run memtest with all RAM installed?

    Speed of the RAM is at 1600MHz and at default BIOS settings?


    I ran Memtest in every configuration I could, all of it passed, although for a few passes it only did the 16GB that the BIOS reports as installed.

    With 24GB installed, the motherboard only uses 16GB, my Avexir Core series 2x8GB. In the Tools tab, under SPD, the BIOS shows all RAM sticks present, yet only reports 16GB installed.

    Inside Windows, System Properties reports 16GB installed as well, however CPU-Z 1.7.1 shows all 24GB RAM present in the SPD and Memory tabs.

    My initial and merged post have the most info about the issue.
    Reply to EquineHero
  8. set the speed of the RAM to 1333MHz

    load Load Optimized Defaults in BIOS

    how did you reset the BIOS? Try again with the clrcmos jumper, while the system is disonnected from the wall socket.

    Maybe the cpu cooler is too tight on the CPU. Losen it just a bit.

    Eventually the CPU contacts are contaminated. Did you touch these? Would clean the CPU contacts with alcohol or similar.

    Have a look at the socket pins again, pretty sure it´s a contact problem
    Reply to helpstar
  9. helpstar said:
    set the speed of the RAM to 1333MHz

    load Load Optimized Defaults in BIOS

    how did you reset the BIOS? Try again with the clrcmos jumper, while the system is disonnected from the wall socket.

    Maybe the cpu cooler is too tight on the CPU. Losen it just a bit.

    Eventually the CPU contacts are contaminated. Did you touch these? Would clean the CPU contacts with alcohol or similar.

    Have a look at the socket pins again, pretty sure it´s a contact problem



    RAM speed is 1333, I already tried that. Right now as of typing it's at like 1410 or something because of BCLK overclock.

    I use the jumper every time.

    I know the cooler isn't too tight, I only use my thumbs and go until it's too hard to twist that way.

    I'll try cleaning the CPU, when I upgraded from my H77M I just moved the CPU.

    There's one pin on the motherboard that's missing, but it's on the VCC/VSS quadrant of the CPU and even then the RAM was still reported as 24GB, when that still worked.

    I blew out the socket with compressed air before my initial post. I'll try again soon and report back. Is there any way I can tell what pins aren't making contact? Intel should make a GUI that shows what pins are being used...
    Reply to EquineHero
  10. The missing pin could be problematic, if the CPU needs it to control 4 DIMMs.

    Do you still have the H77M board?

    Did you use a can of compressed air designed for electronic components or which specific one?

    Or did you use air from a compressor? Then the socket is most likely contaminated with oil.
    Reply to helpstar
  11. helpstar said:
    The missing pin could be problematic, if the CPU needs it to control 4 DIMMs.

    Do you still have the H77M board?

    Did you use a can of compressed air designed for electronic components or which specific one?

    Or did you use air from a compressor? Then the socket is most likely contaminated with oil.


    I used that canned air stuff, specifically on hand for electronics.

    Yes, I still have the H77M board, however it only has two DIMM slots. I know for a fact that all the memory I have works properly.

    The missing pin is not the problem - I've used the board with this CPU with the missing pin with 24GB of RAM and it's worked fine.

    Are there any workarounds for missing pins? Like a tiny solderball on the CPU pad? Otherwise, how would I replace the broken pin?
    Reply to EquineHero
  12. worked fine for how long?
    yes, replacing a broken pin would be very difficult
    Reply to helpstar
  13. helpstar said:
    worked fine for how long?
    yes, replacing a broken pin would be very difficult


    I upgraded from my H77M to my Z77 Sabertooth on the 7th, so that was a Tuesday. I noticed that I only had 16GB instead of 24 on Sunday. So like 5 days.

    I cleaned the CPU entirely, and made sure there were no bent pins and only the missing pin.

    Basically my problem is that the BIOS sees and recognizes all 24GB of my RAM but refuses to report all of it usable by the OS. All 4 DIMM slots work. All of the RAM I own works. Only 2 slots on the board work at a time though, and I'm trying to figure out why.

    CPU:


    On the mid-left-hand side near where the quadrants are separated, you'll see the missing pin:




    CPU-Z SPD info:


    Here's what the BIOS reports:


    Here's the BIOS SPD tool's report for all 4 slots:

    Slot 1



    Slot 2


    Slot 3


    Slot 4


    According to this diagram, the broken pin is a VSS pad so that doesn't matter. The guy I bought it from said it worked fine on his 2600K.


    I saw a video where an Indian guy replaced the pin by taking a donor pin from a fubar donor board.
    Reply to EquineHero
  14. you can try raising the DRAM voltage by 0,05V, just a thought
    Reply to helpstar
  15. helpstar said:
    you can try raising the DRAM voltage by 0,05V, just a thought


    Okay, a couple things.

    You know Windows Experience Index? 1.0 to 7.9?

    When I install the additional 2x4GB, Windows says "new hardware detected". So Windows knows the RAM is there. The BIOS just prevents it from being used.

    I also read here that a corrupt BIOS image could do this. However, I downgraded from 2.1.04 to 2.0.33 and that did not solve the problem.

    The only other thing I can think of is that some other obscure CPU pin is bent - I'll have to remove the board from my case and take a very close look.

    I've raised the voltage up and down, got to 1.67 and still nothing, but I'll try on this older BIOS image.
    Reply to EquineHero
  16. helpstar said:
    you can try raising the DRAM voltage by 0,05V, just a thought


    Okay so far nothing has worked.

    I even cleaned the socket with isopropyl alcohol, didn't change a thing. Cleaned the CPU, nothing. Reseated my AiO, nothing.

    Something's wrong with the board.
    Reply to EquineHero
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