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GA-P55A-UD3 stability + cold boot problems.

GA-P55A-UD3 stability + cold boot problems.
« on: March 04, 2010, 07:38:23 pm »
I'm having some problems with my GA-P55A-UD3 on the latest F6 BIOS.

Here’s a little history:

The first couple of days I built my system it ran flawlessly. After validating things where working solid at default speeds, I followed many online overclocking resources and pushed it easily to 4ghz (20x200), 4.1ghz (20x205) and finally at 4.2ghz (20x210) when something happened. At first 4.2ghz appeared to be stable with IntelBurnTest, Prime95, SuperPI. I then did further testing and loaded up a game, watched streaming video on another monitor while running Prime95. CPU temperatures were all under 70c. All of a sudden BOOM, system shuts down and I’ve had problems getting it stable since. Since then I cannot push it much further than 3.6ghz (18x200 or 19x190) and I’ve found that I’ve had to really push the VTT voltage into the 1.2-1.31v area whereas before, it was left at auto.

I primarily used this review as an OC template (except for RAM timings and voltage which I use 9-9-9-27-1T along with 1.64v): http://www.xtremesystems.org/forums/showthread.php?t=238087

Current problems:

1)   My system’s overall stability has gone to crap. I’m not sure why, but I noticed something strange with my memory. Prior to purchasing my RAM I made sure it was listed on Gigabyte’s compatibility matrix. The problem I’ve been having is my system will simply shut down on its own randomly. This even happens when I’m simply web browsing, and not pushing it. Keep in mind, I can pass IntelBurnTest, Prime95 etc at 3.6ghz.

Booting into Memtest86 and running a test with both RAM modules installed immediately reboots my system. Testing each module individually works flawlessly through multiple passes. I had the RAM inserted into banks 1 and 3 as per the manual. They’re running at 9-9-9-27-1T, 1.64v per manufacturer specs.

2)   I have a cold boot issue. I cannot start my PC w/out resetting the CMOS when I leave it shutdown for several hours. Upon pressing the power switch the fans power on, then off. The cycle repeats indefinitely until I reset the CMOS.

I’ve tried disconnecting every system component except the mother board power, same results. I have not tried out a different PSU yet. I have removed the CPU and inspected it and it appears fine. No burning, no bent pins. Temps have never gone above 71c.

This issue has caused me to update my BIOS from the F4, to F6. I have the same results: This system will simply not cold boot even with a very mild overclock 3ghz (20x150).

I’m really out of ideas. Is it time to RMA the motherboard, the RAM, or the PSU? Where should I start?

Here are my system specs:
I5-750 @ 3.6ghz (18x200):  Vcore 1.35v : QPI/VTT 1.31v : DRAM 1.64v
Gigabyte P55A-UD3
G.SKILL Trident 4GB (2 x 2GB) DDR3 2000 (PC3 16000)
EVGA GTX 260 core 216 (no overclock)
Intel X25-M 80GB SDD
CORSAIR CMPSU-650HX 650W
CORSAIR H50 cooler

Re: GA-P55A-UD3 stability + cold boot problems.
« Reply #1 on: March 05, 2010, 05:27:28 pm »
I have the P55-UD3, which is very similar to yours, and encountered similar boot problems when I first built the system.

My problems were caused by me not understanding BIOS settings (I still don't) and my 'Sata/Raid/AHCI Mode' being set to AHCI and 'Sata Port0-3 Native Mode' being set to Enabled.

Once I put these two settings back to default, I had no more problems. Hopefully, you'll find a similarly simple solution.