Originally posted by: Mokilok Hello everyone,
I'm using AMD OverDrive to test overclocks before applying them in BIOS settings.
My motherboard in a Sabertooth 990FX and my CPU is an AMD 8150 BE.
When I'm raising the voltage and overclocking it hits a wall at 1.45 voltage, at this voltage the CPU clock speed drops lower than the stock speed down to 3.3ghz per core. Is this a safety feature of some kind?
It's possible that AOD doesn't allow higher vcore as a safety feature. Most people agree it is better to OC in the BIOS but Overdrive is OK for some quick tests to get a reference point.
As far as vcore voltage it depends on your specific CPU, what frequency you are trying to run and if you desire a 100% P95 stable system or just 85%-90% P95 stable. Some people are happy with 85%-90% P95 stable but this can lead to a lot of frustration, BSOD, lost data, etc.
The Zambezi CPUs don't OC as easily or as high as the Vishera models but you can still OC them some. At the default vcore you are not likely to get more than a couple hundred MHz. higher before it becomes unstable unless you up the vcore. You certainly could end up in the ~1.45v vcore range for a 100% P95 stable system once you get close to the frequency limit of your CPU.
With a vcore of ~1.40v or higher you need a good tower HSF to handle the heat of an 8-core FX processor. You need to keep the max core temp at or below 61C according to AMD engineering. The higher you go in frequency and vcore the more heat you have to deal with.
I'd definitely suggest switching to the BIOS for OC'ing.
Building a reliable PC involves more than just assembling the parts. You need to be able to configure all of the BIOS settings appropriately. This can be quite involved and frustrating as it can require a lot of trial and error with stress testing. It is however often the only means to get a 100% reliable PC.