Core 2 Duo and Vcore setting (don't use AUTO!)

paapaa · Post by **paapaa** » Tue Dec 12, 2006 7:21 am

I just found out that Vcore really should not be set to AUTO. This is why:

Before: Vcore was AUTO, clockspeed was set to 8x310 = 2480MHz. The temp at idle was 45 and at load 60.

Now: Vcore is 1.200V, clockspeed is 8x360 = 2880MHz. The temp at idle is around 39 and at load 50.

The temp is measured using Intel Thermal Analysis Tool. The load temp is measured using the "Workload" feature of the same program. If I use Orthos I get only 48 degrees at load now.

So AUTO really doesn't seem to function properly with my system. I wonder why the idle temp with AUTO is so high despite the lower clockspeed.

CPU: E6400
MOBO: Asus P5B Deluxe (BIOS 804)
Cooler: Thermalright Ultra 120 + Nexus@12V.

GHz · Post by **GHz** » Tue Dec 12, 2006 8:25 am

Some boards (such as my Gigabyte DS3) increase voltage beyond normal operating specs when the CPU and/or FSB is overclocked. The stock vcore for a Core 2 Duo is anywhere between 1.25 and 1.35 volts. So the reason your temperature is higher even at OC speed is because:

1. You are running below stock vcore (e.g. 1.175 vs. 1.25 volts)
2. At 2560MHz, you are overclocked, so if you tried AUTO your board would either select default vcore (1.25v or above) or something higher because it detects an overclock of the CPU/FSB

HTH!

paapaa · Post by **paapaa** » Tue Dec 12, 2006 8:37 am

Yes. The confusing part was CPU-Z which showed that when using AUTO my Vcore would've been 1.05 or 1.325. Apparently this was not the case and CPU-Z was showing false readings. For some reason it now, however, shows my correct Vcore.

Bottom line is that I hate undocumented features. AUTO??? Auto what??