E8400 what is vcore for 3.6 Ghz and 4 Ghz

hundredislandsboy

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On Asus P5N-D, what is the normal setting for CPU voltage at 3.6 (9 X 400) and at 4 Ghz (9 X 444)? I;ve had my E8400 on this mobo for 18 months and it seems the vcore is creeping up whether on auto or manual (to be stable for P95).
 
Solution
Your VRMs on your motherboard might not be sending as clean of power as it was when its new. Those VRMs can get very hot sometimes and if you never shut your computer down they might be starting to fail. I had a Pentium D 940 in an old Gigabyte board cant remember the exact model but in ran in that bord for 2 and a half years overclocked to 4 ghz and after a year it started to become unstable and I had to keep upping the voltage. I thought it was the CPU but when I moved onto my Core 2 I had to buy a new board because it didnt support 45 nm chips but for kicks I threw the Pent. D in it and OCd to 4GHZ with the voltage I had used from the get on the old board.
over time it will require more voltage to keep a cpu stable. The extra voltage you put in deteriorates the circuits inside the CPU. I have an E8200 at 3.8ghz and it needs 1.29 volts to keep it stable I usually keep it at 3.6 which only need 1.26 to stay stable. I would say for the E8400 3.6ghz should be stable around the same maybe a little less but all CPU are different when it comes to overclocking I also use an ASUS board for mine.
 


Do you remeber what stock voltage was for your E8400?
 

hundredislandsboy

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Are any your E8400s 18 months old that have been running 3.6 Ghz straight almost 24/7? When it was new, it ran stable 3.6 with auto BIOS setting it to 1.29 to 1.3. Now the BIOS (on auto) sets the voltage to 1.35. I went in manually and set it to 1.32 but less than that it becomes unstable fro Prime95.

If it has the dreaded degradation syndrome, I hope it fails in the next 17 months before the warranty expires! Do you guys know of any E8400 that has died from non-extreme overclocking (3.6 Ghz and below) and non-extreme vcore below 1.35?
 

Raidur

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Nov 27, 2008
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Hm, could it have something to do with your mobo maybe? I had mine running at 3.6 for 6 months and 4.0 for another 6 months with zero performance or stability loss. :/
 

werxen

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Check your VID with Core Temp. Mine is 1.25 for stock @ 3.1 but its a E8500. I can hit 3.8 easily with stock voltage but I can't go further without pushing the vcore higher than 1.36... Kinda sucks.
 
Your VRMs on your motherboard might not be sending as clean of power as it was when its new. Those VRMs can get very hot sometimes and if you never shut your computer down they might be starting to fail. I had a Pentium D 940 in an old Gigabyte board cant remember the exact model but in ran in that bord for 2 and a half years overclocked to 4 ghz and after a year it started to become unstable and I had to keep upping the voltage. I thought it was the CPU but when I moved onto my Core 2 I had to buy a new board because it didnt support 45 nm chips but for kicks I threw the Pent. D in it and OCd to 4GHZ with the voltage I had used from the get on the old board.
 
Solution

hundredislandsboy

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The vid of my E8400 is 1.225. On stock speed with C1E and IEST enabled it dips to 1.8 to 1.2 on zero loads. I've been tweaking the BIOS just now and lowered everything, HT, NB volatges and set the vcore to 1.31. I left C1E enabled but disabled EIST

After booting into Windows, CPU-Z reports my core voltage fluctuating between 1.264 and 1.280 while Core Speed stays locked at 3.6 Ghz. I also repaired XP. 30 min of Prime95 and no crashes where before crash, hard lock within 5 minutes.

This makes me think my chip is as good as new and the initial problem was too much voltage across the board. But to be sure, I'll let in run overnight on Prime95. Artic Cooling Pro, Rev 2 keepsone core max temp to 61 and the other to 56 @ fan speed near 1900 rpm. Thanks for the tips guys!