As this is my first attempt at overclocking, i would like a second opinion from you guys, i want to make sure i did not miss anything.
First, the spec i got a few years back, the idea i had was for all the parts to be quite easy instead to overclock at a later stage (and the time has come)
Asus Croshair IV Formula
AMD Phenom II X6 1090T BE
Corsair A70 air cooler
Patriot Viper Sector 5 2x2GB Memory kit (1333 Mhz)
Sapphire ATI Radeon 5870
Corsair 850W modular PSU
While i did read about the auto-overclock feature of my MB, i opted for a BIOS overclock instead.
So, after disabling Cool n Quiet, C1E and Turbo, and setting my memory to 1.65V and 7-7-7-20, I went ahead with playing with the CPU.
For starters, i wanted a small overclock so i decided to try 3600 (as if running in turbo mode all the time).
I have only changed the multiplier (from 16x to 18x) and after a bit of trial and error the Vcore to 1.3 (which felt really low, as the default turbo has a 1.42 setting if i am not mistaking). All other voltages were left on AUTO, and this is where i am a little concerned - is there any chance of the motherboard adjusting these voltages up to an overload point?
The PC was stable, and the temp under load was 38 degrees, indicating the chip can be pushed safely quite a bit more, though i only ran an 1 hour test using the AMD Overdrive application.
As a side note, after reading that during the stress tests you should keep a close eye on the temperatures, what do you guys do while running 8 or more hours tests?
The second question i have is what would be the top frequency i should aim for a 24/7 overclock (i plan on using this PC for a little bit more so i want to make sure i am not reducing the cpu's life span).
I use Intel CPU's, but you are asking mostly generic questions, so with that caveat ...
Learning to use the BIOS is good.
First of all, when I am overclocking, I disable SpeedStep (Intel's equivalent of Cool 'n Quiet), work out and test the overclock settings, then go back and enable SpeedStep). If you are running 24/7, your CPU will not be at a constant 100% load unless you are folding or something similar. So if it is idling, there is no point in letting it idle at full speed.
The problem with Auto voltage settings is that the BIOS will frequently (and needlessly) overvolt.
I do not know if AMD Overdrive puts a 100% load on each core (I use Prime95), but 38 C load temps means that you do have more room.
A 100% load on all cores will drive CPU temps to their max in less than 15 minutes. I do my final stress testing for 24 hours. But by then, I know what to expect, so I sort of watch it, then go to bed and let the test run overnight.
I pretty much go for the max stable overclock I can get with SpeedStep enabled while staying below Intel's max recommended voltage and temp. Fortunately, with my case and cooler combinations, I reach core speed limits before I reach voltage or temp limits.
Thanks a lot for your reply jsc. The idea about re-enabling Cool 'n Quiet makes a lot of sense, i will give it a try.
Now with regards to the Auto voltages, i dont mind if the BIOS overvolts as long as it is still within the safe limits (and now that i put it like this, i highly doubt a motherboard will automatically overvolt outside a safe margin, right?)
AMD Overdrive does put a 100% load on all cores, but i will give Prime 95 a go as well and run a 24 hour stability test.
Now about the 24/7 overclock, i did not express myself properly as my PC runs at most 5-6 hours a day, what i meant was what frequency i should aim for without putting too much stress on the chip, as i am hoping to use this system for at least one year.