I would suggest also including the links of the validations in OP!
, P95(B) + IBT(50)
Btw this time it's 4.2GHz Prime95 blend 24-hour stable and IBT 50 runs.
Originally Posted by drummr91
I guess I'll join. I don't see how people are getting 4.5ghz+ out of the 970. Either I ended up with a bum chip, or I don't know what I'm doing. This is my max that is prime stable for more than 2 hours.
To overclock methodically, follow the guide I made from my own experience!
Here's a solid overclocking method developed by yours truly, after having read MANY guides.
Firstly, set everything that is [auto] to [manual], even if it's default. PCI-e bandwidth, system voltages, everything. Turn off all that Cool'n'quiet garbage ; whatever could possibly throttle your precious AMD masterpiece.
First phase consists in determining your stock ceilings; finding the maximum values here will allow you to understand and "feel" your CPU better.
Stock voltage phase: (Click to show)
1. Keep voltage stock. Bump up Northbridge, and test stability with 10 minute runs of Prime95 blend.
2. Do the same for the CPU FSB, using whatever multi you need to stay at stock (3.2GHz for me). Test stability using smallFFT's, 10 minute runs ; alternatively, Intelburntest V2. During this stage the multi and CPU fsb are inversely proportional, while maintaining your stock frequency (+- 200 MHz, doesn't really matter).
3. Repeat for multiplier. In your case it seems like you found 20.5. Test stability with SmallFFT's, 10 minute runs ; alternatively, Intelburntest V2.
With these three stages, you found the highest limits of the CPU at stock voltage. This is to give you an idea of what your CPU is capable of.
On my own 955, I found:
NB: 2880 MHz
CPU FSB: 260
Multiplier: didn't care, I overclock with FSB primarily. This yields a higher performance overall. I think it was around 20, 21Now is the O/C'd voltage phase: (Click to show)
Now, set the maximum voltage you're going to use, that you're comfortable using. I would suggest 1.45V. Run Large FFT's to check the maximum heat output. Ideally, you want to stay under 60C for AMD chips. My chip is at 50C load; it depends on the chip, and the cooling. The voltage will directly affect the heat output, even if the frequency hasn't been adjusted. Play around with the voltage (<1.5V) until you find a suitable temperature.
Key: under 1.5V, under 55C (AMD). Intel chips can tolerate a bit more heat. If you look at some of the LN2 runs on OCN, you'll see that people have pushed 955's to 5GHz+ on stock voltage; AMD chips need to be cold to be stable, not more voltage, although it does help.
2. Set all your clocks to default.Now, with your maximum comfortable VCore voltage, set the CPU-NB to stock. If you can monitor your NB temperature, then put it to 1.3V. Keep it around 1.3-1.4V maximum. Bump up your Northbridge and test with 10-15 minute runs of Blend test in Prime95. Once you've
Northbridge usually ends up around 2600MHz - 3000MHz.
3. Set Northbridge to a tame overclock for this part; 2400MHz will do. Now bump up the FSB in increments of 5MHz. I started at 250 right off the bat, though it might not work for you. Once you've reached an instable frequency, go to the last known stable frequency and increase in increments of 1MHz.
My max FSB was 260, you might be able to go a lot higher.
Once you have the maximum northbridge, FSB, and voltage, things get interesting. At this point you'll be playing with all your different settings together.
Set your maximum FSB (first) since your NB is dependant of it.
Set your maximum Northbridge (ex: 2800MHz)Finding max CPU Frequency: (Click to show)
Now bump up your multi in 0.5x increments. You can start at around 3.6GHz, since it *should* be stable from 3.2-3.6.
Then, what's you've reached an unstable OC - say, 4GHz - start lowering the FSB and multi, balancing them out to achieve a higher OC.
250x16 = 4GHz
Try out different combinations, and see what combinations give you the highest stable overclock.
With each combination, test for 10 minutes of IBT or P95, your choice.
Once you think you've found your highest ceiling, test for 25 runs of IBT, or more depending on your preference. 25 is usually a good bar, along with 12 hours of Prime95.
By figuring out FSB, VCore, and Northbridge independantly, you're finding the best possible combination for an overclock.
A rigorous, methodical approach is best.
My build is undergoing 500 runs of IBT simultaneously with a 24-hour Prime95 Blend Test, followed by SmallFFT.
Before this method, I acheived an unstable 4.0GHz on my 955. Now, I'm at a comfortable, stable 4.2GHz
If you want to go hardcore stable, use F@H to test it. Even when IBT and P95 were stable, F@H has found a flaw. Most importantly, TEST with the programs you will be using daily.Edited by dmanstasiu - 2/15/12 at 9:50am