M3A78-EM + Phenom II 955 + Patriot 1066


I'm having a hard time getting my memory to run stable at 1066Mhz.

The parts involved:
-Asus M3A78-EM (Bios updated to version 2003)
-AMD Phenom II X4 955 HDZ955FBGIBOX 3.2 GHz/6 MB L3/125W Processor (AM3)
-Patriot PVS24G8500ELKR2 Extreme Performance Viper Series PC2-8500 DDR2 1066MHz 4GB (2x2GB) CAS 5-5-5-15 EPP Ready Enhanced Latency Dual Channel Kit (Black)

Other hw (maybe relevant):
XFX RadeonHD 4890 1 GB DDR5 Graphic Card HD489XZSFC
750W PSU PFC 80+

If I just turn it on with everything on auto, the mem runs at 800Mhz. After playing GTA4 for 1 or 2 hours, it crashes.

If I set the mem to 533 (1066), the timings to 5-5-5-15, the voltage to 2.1 (as the memory specs says), GTA 4 runs for a couple of minutes then crashes.

The CPU, Mem and vidcard are brand new. The parts that were in before those were Athlon 64 x2 6000+, 4x Kingston 512MB 533Mhz and a 9600GT. GTA 4 ran with no crashes, for hours.

Am I missing something here? Should I raise NB voltage or do something else to keep up with the 2.1v recommended by patriot?

Any comments are appreciated,
11 answers Last reply
More about m3a78 phenom patriot 1066
  1. maybe it's heat related?

    it seems that you're doing things fine by raising the voltage to 2.1 and inputing the timings. are you sure you changed the correct items to reflect in the memory timings? i'm not TOO knowledgeable about this kinda stuff but it seems to me that you're doing things the way it's supposed to be done..

    somebody chime in?
  2. also, try testing your memory on memtest.. you can find it on google easily..
  3. ^+1... Also think your memory to be the problem. Asus AM3 boards are now really good with their latest BIOS.

    Check each stick with memtest.
  4. After memtest try lowering your frequency to 400Mhz and voltage to 1.9v. Run the RAM at 800Mhz and bench with 3dmark06 or equivalent. If it does not crash then it's your mobo not being able to handle 2.1v. I had the same exact issue and had to run the Ram at 800Mhz (1.9v) in order to get a stable system.
  5. Thanks everyone for the suggestions and tips. I've been out of town and am coming back tonight. So I'll try everything when I get home and post the results when I figure out what works and what doesn't.

  6. I ran memtest86. If the memory is at 800Mhz, it runs fine. I left it running through the night and in the morning was still running with no errors. But if I set it to 1066Mhz, it fails pretty quickly (test 4 or 5). Tried just setting the clock and leaving everything to auto, tried setting all the parameters (5-5-5-15, double checked the correct items)... Everything ended up in failure.

    So right now I'm running it at 800Mhz, and was waiting for a response from Patriot, that just arrived asking me to test the mem modules individually (I only ran memtest with both modules on). I'll do that later tonight and reply...
  7. The modules are fine, it's your motherboard not being able to handle 2.3v.
  8. Patriot says the voltage should be 2.1. I did set it to 2.1 to the same results. Should I set it even higher? How high can I go, without the risk of damage?
  9. Yea i was looking over at this site and they have wrong info :


    anyways it's your mobo not the ram itself
  10. The memory voltage setting goes higher than 2.1. Should I try to set it higher? How much higher is it still safe?
  11. If your ram is not stable at 2.1 I doubt it will be stable at a higher voltage, you can try if want, just no guarantees....

    Dont go higher than 2.3v
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