Weird OC behaviour - PSU faulty?

[xinhang]

I'm experience a very weird OC behavior and it has happened repeatedly. First of all my components are:

i7 860
Asus P7P55D premium
4 x 2GB G.Skill Turbulence 2133mhz
XFX 5870
Antec Quattro 850w

The weird thing is, every time i reach a stable OC (tested by 2hr+ prime95 and 2 pass memtest86) then after i shut off the computer and turn it back on 12 hours later the OC would fail. Also i notice the temperature would drop significantly from (50 -> 42) from startup. This phenomenon has happened over 5 times already. Sometimes the computer would be perfectly stable for couple of weeks then one day out of no where it fails. Also i noticed sometimes when after OC failed, if i shut off the computer and turn it back on it would miraculously fix itself. I really don't know what is going on. Any input is appreciated.

Thanks

Xin Hang

[Synth]

Originally Posted by xinhang

I'm experience a very weird OC behavior and it has happened repeatedly. First of all my components are:

i7 860
Asus P7P55D premium
4 x 2GB G.Skill Turbulence 2133mhz
XFX 5870
Antec Quattro 850w

The weird thing is, every time i reach a stable OC (tested by 2hr+ prime95 and 2 pass memtest86) then after i shut off the computer and turn it back on 12 hours later the OC would fail. Also i notice the temperature would drop significantly from (50 -> 42) from startup. This phenomenon has happened over 5 times already. Sometimes the computer would be perfectly stable for couple of weeks then one day out of no where it fails. Also i noticed sometimes when after OC failed, if i shut off the computer and turn it back on it would miraculously fix itself. I really don't know what is going on. Any input is appreciated.

Thanks

Xin Hang

I start considering an OC stable after 8 - 12hrs of Orthos, not 2hrs.

Bottom line, in my opinion, is that your OC was never stable to begin with.

Cheers!

[Dr_BenD_over]

If you've left a lot of settings to Auto in the BIOS, that could be causing your issues.

[martin_metal_88]

First of all, prime is sissy. Use LinX running 20 pass with the option all test checked. THIS will tell you if your OC is stable. Second, This look much more like a problem coming from the mobo, probably the BIOS a option in the bios left on auto or just a bad setting. Also, having a lot of memory can reduce OC. I was having some frequent freeze when using 8GB of memory at 4Ghz, now running with 4GB and 4Ghz was 100% stable for week folding 24/7.

Also, is the issue happening only with WoW? I know the game have issuewith 64Bit system and memory. Since every freeze ( coming from any source ) can make your OC to fail that could be the issue.

[xinhang]

Yes, unfortunately a lot of the settings are left on auto. I guess i will set them manually and use Linx to test stability. I also find using 4 DIMM is much less stable than 2 DIMM. I'm trying to reach 3.8GHZ stable for my i7 860 with HT on.

Can someone suggest me some voltage for reference. I know each chip is different, but I would like to have something to compare with. Thank you so much in advance.

[martin_metal_88]

Well...for my 860 at 3.8 Vcore was at 1.38 or 1.39 and VTT was at 1.24 if I remember good. Try getting it 100% stable with 2 stick and the lowest voltage needed, then add the 2 other stick and see if you can get it stable.

[xinhang]

That much vcore? My temperature is already over 75 with 1.25 vcore (unstable apparently). I'm using a scythe mugen 2. Do you turn HT on or off?

[martin_metal_88]

I was HT on. under a prolimatech megahalem and then a complete WC with a tripple rad. but well...set vcore to stock, then press + 1 time, try it. If it fail press + 1 more time, and do it till it get stable. best way to do:)

[xinhang]

Sorry another question. Do you enable speed step?

[xinhang]

Finally reach a stable clock w/ a decent temperature. First of all, i changed the thermal paste from artic silver 5 to artic cooling MX-4, which made a HUGE difference when i tried to OC. Currently my setting is:

vcore: 1.288
vtt: 1.275
dram. 1.65

CPU: 190 x 20 = 3800mhz
RAM: 190 x 8 = 1520mhz (cas 7, 4 DIMM)

Idle temperature: 26-30
load temperature: 77-81

Passed 20 runs of intel burn test with maximum stress (8gig or ram, ram for ~2 hours in total). Also passed 5 pass of memtest84. I hope this will give my system some stability tomorrow when i turn the computer back on.