Overclocking an E8400 to 3.0GHz on stock cooling


Jun 27, 2009
EDIT: I just realized i put 3.0GHz in the title instead of 3.6GHz and it won't let me change it. Yay for 0% overclocks lol...

Hi all,

I recently completed my first build without any problems (luckily) and I am more than satisfied with the performance of my system. Even so, I thought I'd take a shot at overclocking my E8400 from 3.0GHz to 3.6GHz. After reading numerous guides, I slowly but surely reached 3.6GHz small increments at a time, achieving some degree of stability (I hope).

Before I post my settings, here are my system specs:

Intel 45nm Wolfdale E8400 C2D @ 3.0GHz E0 Revision
EVGA nForce 790i Ultra SLI Motherboard
2x2GB Mushkin 996585 DDR3-1333 RAM 9-9-9-24
EVGA GTX 260 Core 216 Superclocked 896 MB Video Card
Corsair 520HX Modular 520w Power Supply
Western Digital Caviar Black 640GB 7200rpm 3.0Gb/s 32mb Cache Hard Drive
Samsung DVD Burner Combo Drive
NZXT Tempest ATX Case w/ 6 Fans

I used the following bios settings to reach 3.6GHz:

CPU Multiplier: 9x
FSB - Memory Clock Mode: Unlinked
FSB (QDR), MHz: 1600
MEM (DDR), MHz: 1333
CPU Core Voltage: 1.25000v
CPU FSB Voltage: 1.15v
Memory Voltage: 1.500v
nForce MCP Voltage: 1.500v
nForce SPP Voltage: 1.30v

After several hours of Prime95 stress testing and monitoring temperatures with RealTemp and voltages with HWMonitor and CPU-Z, my system experiences the following with no errors:

Idle Temps: 38C-42C
Idle Vcore: 1.224v
Load Temps: 55C-60C
Load Vcore: 1.200v (I'm assuming this is the VDroop kicking in.)
CPU FSB: 1.32v
DRAM: 1.82v

Note that this occurs with the stock Intel CPU heatsink.

A few questions:

- In general, are these safe conditions for long term 24/7 operation?
- Are my CPU temperatures safe?
- Why are my FSB and DRAM voltages higher than what I set in the BIOS? This occurs even at stock configuration. Is this safe?

I've also read about linking and syncing my RAM to the FSB, what are the benefits of this? Is there anything wrong with running my system with a 3:5 FSB-RAM ratio?

Also, I plan on buying and Arctic Cooling Freezer 7 Pro heatsink in the near future. I'm kind of hesitant about the installation of the pins though, as the ones on the stock Intel cooler required intense amounts of pressure and I know they both use the same mounting mechanism. Is it just as troublesome to install? Will I have to remove my mainboard first?

Any help is appreciated, thanks in advance. Sorry about how long that was. :D


Mar 6, 2007
92-class HSF is outdated. You can get a Xigmatek S1283 for same/less price now: http://www.newegg.com/Product/Prod [...] &Tpk=S1283

Even with the push-pin Intel system you should remove your MB from your case to properly fit the new HSF.

As far as the OC don't go higher with the stock cooler and the temps look OK but I'd change the HSF for 24/7 operation


Jun 27, 2009
Thanks for the help, nocteratus.

I think I actually might go for that heatsink, the bigger 120mm fan seems so be the better choice. Not to mention Newegg has a mail in rebate for it so its only going to be 20$. :D

There's a slight problem though. On my mainboard, the CPU is surrounded by 4 built-in heatsinks, one of which is rather tall and has a fan of its own.

Here's a pic:

The fit might be a bit tight with the S1283 but I guess I'll just have to try it. I already have some AS5, what should I use to remove the stock thermal paste?


Apr 16, 2009
I don't think the S1283 comes with TP applied already, but it might come with a tube of TP. If it does have TP already applied then use something like Isopropyl Alcohol and clean it up.