Weird RAM Problem? G.Skill F3-12800CL9D-4GBRL

vaga13ond

Junior Member
Dec 4, 2007
10
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I've never encountered this problem before but before I send them out for RMA I figured I would post the problem here.

Basic system:
Motherboard: Gigabyte GA-P55A-UD3
CPU: Intel i5 750
RAM: G.Skill Ripjaws 2x2GB DDR3 1600F3-12800CL9D-4GBRL
OS: Windows 7

Recently put this system together and have no seen issues with stability in the week that it has been built. Randomly the PC internal speaker would let out a very quick blip while in Windows, I had the fan alarms set so I figured it might just be a millisecond when the fan lead didn't pickup correctly. Also, sometimes during reboots and startups the computer would not post and the BIOS error for memory (endless fast beeping) would kick in for unknown reasons. A few tries of the reset button would get the system to post. Since that time I've updated the bios to the newest revision (f4) and turned off all the fan warnings. Never encountered BSOD

Now, everything for the time being in bios is on the optimized defaults. With the new f4 bios I don't get the random beep in Windows anymore but I do occasionally have one of my ram sticks 'disappearing' from Windows as it reads only 2Gb of memory. Also, occasionally the system will post with only 2GB of ram showing.

I've reseated the RAM, changed positions and it still happens. I think I found the offending stick and the problem is strange... I run memtest86+ on it, and it passes all the tests fine, and then if I reboot directly after (or after any kind of memory intensive program) that the stick won't post. BUT if I just let the system hammer that stick like either running prime95 or memtest86+ I get no errors for hours. Just that once it's heated up and I reboot, it won't post or occasionally it disappears from Windows.

I'm guessing this should be RMA'd? Just seems weird that no tests show any errors, just it doesn't like being heated up and then left alone or something since then it'll disappear from Windows or just not post.

Someone on another forum asked me to do some SPD 'dumps' so I'm not sure if this is what he meant but figured I would include this anyway.

Both sticks are installed (2x2GB) but after a memtest86+ run the first stick (DIMM1) didn't post. You can see that Windows recognizes that the RAM is there but it is disabled or 'hardware reserved.' As
spd.jpg




Rebooted and pulled the assumed good stick so I was running the single 'bad' stick 2GB while running prime95 in the background:
spd1.jpg




After prime95 ran for about 10-15 min and I rebooted the stick wouldn't post for about 3+ minutes during a reboot so I decided to put back the second stick and after a few reboots I got them both to post:
4gbpost.jpg




Ran 2 instances of prime 95 for about 10 minute and rebooted. I couldn't get the system to post after 3-4 minutes so I decided to reseat the chips. After fooling with it some more and letting stuff cool down all was able to post and boot again. The weird thing is that I never have had any stability issues with the RAM nor whenever it's tested (if I can get it to post and Windows or Memtest to find it) it passes all the tests fine for hours.
 

railman

Member
Dec 22, 2009
82
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I notice your ram is XMP enabled. Do you have an option in your bios to set the ram as XMP or a way to run an XMP profile of ram timings? If the ram test good I would be more inclined to think you have a timing problem or a voltage issue. Have you tried the G.Skill and or the Gigabyte support sites or forums? Would be a good idea to post there as well. Someone there may have had your problem also.
 

vaga13ond

Junior Member
Dec 4, 2007
10
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0
Where do you see that the XMP profile is enabled? If I'm reading this correctly my memory is running @ a single channel frequency of 666 MHz or 1333 MHz for dual channel. So it's not going at the XMP profile (or what this is rated for) which shows it should be running @ 800 channel freq MHz or 1600 MHz dual channel. Am I wrong here? Bios states and it's disabled and I manually set everything to run @ 1333 and all the information (and bios agrees) that it's running @ 1333?
 

railman

Member
Dec 22, 2009
82
0
0
You misunderstand me. I mean your ram is XMP capable, have you tried running the ram with that profile? If your machine runs stable using the XMP profile you should be good to go.