Can't OC CPU past 1600FSB on EP45T-DS3R

[HD4850]

This is a really weird problem.. it seems whenever I set try to set the FSB at ANYTHING higher than 400, I would get a "data corrupted" error when extracting large winrar archives. Right now, I have the FSB set to 400 on my E8500, which is COMPLETELY stable in Prime95, and doesn't give me any errors in winrar.

I do not believe it's a temperature problem, since my CPU never even hits 50c on load. My Northbridge & Southbridge temps never go past 45c.

My rig:
OS: Vista Home Premium 64-bit
CPU: Intel E8500 @3.8GHz ~stock voltage~
Gfx Card: Radeon HD 4850
Memory: 4GB DDR3 1333MHz Patriot
HDD: 1.5TB Seagate
MB: Gigabyte GA-EP45T-DS3R
PSU: Antec TruePower 750w
Case: Antec Twelve Hundred

believe me, I've adjusted the voltages like crazy... I've been working on this for days. Even if I set vCore to 1.4v, MCH core to 1.4v, PLL 1.6v, vtt 1.38v... nothing seems to matter, even if I raise the FSB to ONLY 402... it will still be unstable.

It's very weird because at 400 or below, everything is completely stable with stock voltages... Right now, I'm thinking it's my motherboard keeping me from getting past 400fsb. What do you guys think?

 

[chizow]

P45 should be able to pass 400MHz FSB without problems. My guess would be a memory hole, or a resulting overclocked frequency that's unstable. Could also be a RAM stability issue although DDR2 1333 should be fine up to 666 or whatever. Easiest way to test is to drop the multiplier on your CPU a few notches and then increase FSB by 12-13MHz to see if you can jump any potential memory hole. Once you find your max stable FSB and any holes, you can then go back and raise your multiplier to come to your desired OC frequency.

 

[HD4850]

lol it's "DDR3" RAM bro, not ddr2. I also think it's a problem with the RAM... but I don't know how to fix it.

I don't think it's a memory hole because I've tried 401x9.5, 422x9.5, 432x9.5, 453x9.5

They all boot up into windows, but still gives me those "CRC Failed:file corrupt" errors when extracting large winrar archives.

Right now I believe what I need to do is MANUALLY adjust every single setting in the memory advanced settings.

 

[theAnimal]

Your RAM is already OCed by 20%, so loosen timings and increase voltage.

 

[HD4850]

no no, trust me, I've tried all of that lol.

I believe I've found the culprit. There's a menu labeled as "CPU Advanced Clock Control", and it has 4 settings with 800mV/900mV, 0ps/0ps. I believe I must play with these. What do you guys suggest I set them to?

EDIT: I just found this link that MIGHT solve my problem:
http://www.ocztechnologyforum....howthread.php?p=285270

It even mentions running the E8500 over 400FSB, o_o ..so i think this will be my last resort. I'll try it out and get back at you guys with the results.

 

[polarbear6]

ahh had the problem with a g33 board with my e8400
i will bookmark this thread n see what the solution would be

 

[HD4850]

Problem solved.

It was indeed the clock skews settings. Raising each setting allowed me to go past 400fsb, and I no longer get errors in Winrar. Now I can OC my chip further =)