Classified Overclocking

Manual Overclocking

The eVGA BIOS has a very nice Dummy OC feature auto overclocking the processor. Of course real tweakers and overclockers spit on automated overclocking, and with a little time and trial you can certainly achieve very hefty overclocks. For this test run we overclocked both a Core i5 750 and a Core i7 870. The overclocks you'll see are 100% stable, from our test sessions we'll show you the overclocked results in all of our benchmarks.

So with the Front Side Bus officially annihilated, things tend to change a little while overclocking a Nehalem based processor. Only a little though. It's a little weird but the concept remains the same. In the BIOS you'll find a 133 MHz register, that is the BASE CPU clock... look at that as your 'FSB' to play around with. Of course, with an Extreme Edition processor, things would be much easier, unfortunately this is not the case with today's launched processors.

All three processors released today are multiplier locked, meaning your starting point is to select the highest possible multiplier in the BIOS and then increase that base clock

Don't be afraid to play around with CPU voltages as even on the stock air cooler you can achieve some pretty snazzy results.
 

Core i7 870 overclocking

First up for this processor, check what your current maximum multiplier values are. We fire of a higher base clock to that multiplier of 22 ot with Turbo mode enabled -- 24.

As such we where able to overclock the Core i7 870 processor to 4.2 GHz (!) with a mainstream Thermalright MUX 120 air cooler. Here's what we did:

BIOS settings:

• c1e disabled
• cstate disabled
• turbo/speedstep on
• cpu host frequency = 174 -> that will give you 24x174 - 4178 MHz
• boot up cpu vcore at 1.40v
• Eventual CPU VCore at 1.40v
• bootup VTT at 1.35v
• eventual vtt at 1.35v
• dram 1.65v
• vdroop disabled
• dram ratio = 2:10
• CL settings according to your rams.

At 4178 MHz on the air cooler we easily booted into windows, anything over 4200 resulted in a crash.

When we stress the CPU cores with prime 95, temperatures now rise to 80 Degrees C (176F) which really is close to the maximum limit you want to go to. But either way, the air-cooled overclock is just downright good.

Overclocking itself, it is a pretty easy thing to achieve with this processor. Mind you that overclocking will draw a lot of power from your system. We'll show you that on the next page.