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Overclocking my e8400 on XFX 790i ultra mobo, help please!

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k992

Registered
Joined
Aug 11, 2008
Hello everyone, i was trying to overclock my e8400 on XFX 790i mobo to 4Ghz, but i could not get my system to run stable at 4Ghz, i get a blue screen sometimes, my bios settings were:

FSB:1777
Cpu voltage: 1.3625V
Cpu FSB(VTT): 1.35V
Memory voltage: 1.80V
nforce SPP: 1.45V
nforce MCP: 1.60V
GTLVREF lane0: +45mv
GTLVREF lane1: +40mv
GTLVREF lane2: +40mv
GTLVREF lane3: +45mv
Other settings on auto, memory fsb set to unlinked.

If anyone has done overclocking on this motherboard before, could you tell me what are your settings please?
What do i need to change in bios to get my e8400 run stable at 4Ghz?

Thanks so much.
 
Firstly, I wouldn't push your FSB voltage any higher .. 45nm CPUs are very sensitive to it and you can kill them easily with higher VTT .. Also, boost the MCP voltage to 1.65v (it helps with stability) ..

Your problem might simply be that your vCore is too low, you chip might want some more .. The trick to getting stable with the 790i board however lies in the GLTVREF voltages .. I'm afriad you'll have to fiddle with those to get it goin good. Adjust them and then stress test for a while ..
 
Downclock to like 3.6 and run prime for hour, if it stalbe move to 3.8 and repeat. Cpu probably needs more vcore.

What are your temps like? Vdroop?
 
Thanks for the replies guys, how to i find out what my vdroop is? My temp are around 45C idle and 54C at load according to realtemp when i run it at 4Ghz before. And about the GLTVREF voltage, should i try increase it first or decrease it?

Thanks guys.
 
vDroop with the 790i boards is just awful .. I have my vCore set 1.35v and under load my vCore is ~1.265v .. I would bump the vCore some and then do as I said n fiddle with the GTLVFREFs .. I'm afraid we can't tell you whether to increase or decrease because each chip is different .. You'll be able to notice increased instability when you stress test so use that to clue you whether to increase or decrease
 
Ok thanks Anubis, i will try to figure that out, but any suggestion on what vcore voltage should i set? For 4Ghz.
 
Ummm anything up to 1.45v .. My E8400 needed 1.45v infact .. Just keep an eye on the voltage reported by CPU-Z when your stress testing .. You'll notice its a fair bit lower then the voltage you set, this is vDroop .. With my board, the idle voltage is around -0.04v less then the BIOS set voltage and the load voltage is around -0.08v less.
 
Just one last question, if any of you have used realtemp and coretemp, which one shows the cpu temp more accurately? Because in real temp, my cpu temp is shown as 60C at load (running e8400 at 4Ghz), and in core temp it shows my cpu temps are 70C at load, a 10C difference!

Ofc i would hope real temp is more accurate in this case, but would like to ask you guys first since i am a newbie.

Thanks.
 
Hi, this overclocking is getting way too difficult for me, i have now increase my cpu voltage to 1.45V and GTLVFREFs voltage all the way from 30mv to 80mv, but my pc just wont run stable at 4Ghz.

I have ran prime95 to test my cpu, but everytime i make an voltage adjustment, i will always get the same result, the test went fine in the first 50 mins, then after that one of the core just stop working.

Please if anyone know the solution to this problem, please tell me.

Thanks.
 
Thank god you are still awake Anubis!

I think core number 2 is the one that keeps failling according to prime 95, the core at the bottom window, whenever i run 3dmark 06 on my pc and if the graphics get really doddgy, i know its time to press esc to exit and i can see that in real temp, one core is around 7-10C cooler than the other.

I cant believe that i have up my cpu voltage to around 1.47 and GTLVREFs ( all four of them) to 80mv and still cant get it stable.
 
It's all about getting those GTLVREFs right with the 790i boards .. For stabililty those make or break it .. My X3350 Quad needed a ton more voltage to be stable before I got them right.

How many DIMMs of RAM do you have? Sometimes these boards don't play well with 4 sticks and high FSBs, you could try loosening the RAM timings a tad and giving them a little more voltage.
 
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