Phenom/PhemomII OC Guide?

B-Unit

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I was wondering if anyone knows where a good guide to OCing K10 procs is. Ive got a PII 940 that I cant even get prime stable at 3.6Ghz, and I dont know what else to try.
 

B-Unit

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Here's a CPU-Z shot...

15p28hj.jpg


Running on ASRock AOD790GX-128M. Memory is the G.Skill PI Black DDR2-800 modules. Upped to ~1.45(lots of fluctuation on this board) and got 2.5 hours prime stable this afternoon at these clocks. Not sure why, but I cannot get the HT to go over 1800Mhz. NB has been fine as high as 2600, but HT only goes up if I increase the ref clock.
 

unclefester

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That's not a type-o is it? ~1.45v to your memory. The default voltages should be in the BIOS is 1.8v, That's why I ask.
From the specs I see at NewEgg there rated at 1.8v to 1.9v
And I sure you will need every bit of the 1.9v to get passed @3.6
I'm using OCZ reapers running at 2.28v and just raising up from 2.26v really added to stability at @3800
 

unclefester

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My bad!
When I got to thinking about it, you made it to @3800 at 1.45v on the CPU.

Now if remember this right to up the HT you will need to set the CPU-NB HT Link Speed, mine is set to 2.2 GHz. this should allow you to up the Processor Frequency Multilpier, mine is set at 11.00x
I have heard conflicting stories on whether to run any higher than that. Some have said there are unstability issues going higher, others say they can run higher, and yet others say it can shorten the life of the board significantly. the jury is still out on the last one.
 

B-Unit

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Yea, thats the part I dont understand. Regardless of what I set NB Link Speed to, I get 1800 Mhz. Infact, I think it was at 2200 or 2000 when I took the screen shots. I did some testing to find max stable ref clock (roughly 300 Mhz, btw) and the HT speed came up that way, but my multi doesnt seem to affect it.

So I guess my question is, I know HT cant exceed NB speed, but is it best to keep them in sync? Or should I turn the NB back up?
 

unclefester

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http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3512&p=11
This article may help as guide. Although I have heard in various forums, that settings above 2000 can become unstable or even damage the on chip memory controller. And you may or may not see any gains by having more bandwidth on the NB.
About being synced, have had the most success with them both at the same speed. And you already know the old saying "every machine is different".

After looking at your screen shot, I noticed you memory is in Unganged mode. In single threaded apps. you will see better results (ie.... benchmarks) and may help with stability at higher clock speeds using Ganged mode.
 

unclefester

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If it makes you feel any better I have most-of-the-heimer's LOL

Ganged memory is utilizing one stream of data at 128 bits, accessing all sticks of RAM.
Unganged is running 2x64 bits of data 1 stream on each memory controller.

If I could figure out which DVD I have it archived on I could give you a better explanation. ($%^* most-of-the-heimer's anyway!!!LOL)
 

B-Unit

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Heheheh, I now how that goes.

Ganged mode got me prime stable at 3.5Ghz (2600 NB, 1800HT) for 9 hours, so Im gonna bump it up to 3.6Ghz and see what happens.

EDIT: Also, I havent been able to get a good verdict on ACC. Leave it on auto or is there tweaking to be done there as well?
 

unclefester

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I have read in a couple of different forums that the ACC is actually built into the chip on the 940. I tried ACC twice, once using AOD, and another time in the BIOS. Both times it ended up with me having to clear the CMOS.
 



Both the articles I've read on overclocking the phenom 2's (anandtech and here on tom's) say to turn off ACC as it is already on chip.

I didn't notice, did you say what your cooling method is?
 

B-Unit

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Im using an Arctic Cooling Freezer64Pro. Temps go between 50-55C while Prime testing.

Ive had ACC on auto, Ill turn that off as well and see if that helps.
 



That cooler is ok, but I would recommend something better if you wanna go north of 3.6ghz. I was using a Thermalright ultra 120, but have since switched to a coolit ALC domino and couldn't be happier. I am tweaking it currently but I stay at a chilly 36C on medium speed and 40 load with core temps maxing out about mid 50's.

I am running at 3.7ghz with 1.4125V on the processor. I am justb starting to tweak HT and northbridge speeds.
 

B-Unit

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Yea, I'm eyeballing a new cooler. Had a shot at one of the new Arctic Extreme coolers, but I hesitated and they went out of stock overnight.
 
well, I am having trouble myself reaching stability at 3.8 ghz w/o increasing voltage from 1.4125 and anything higher than that and my temps climb pretty fast. I am pretty satisfi4ed with a 3.7ghz day to day overclock.

I haven't been as successful with the ht and northbridge speeds, guess I just don't know enough about that.
 

B-Unit

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Update for everyone.

Ive been running Prime95 since noon Monday, and Im proud to say shes rock solid at 3.6Ghz 1.48-1.5V in CPU-Z (BIOS set to ~1.46V) and bouncing between 50-52C. I have a Xiggy 1284 on the way, with a little luck I can push a bit higher.

Thanks everyone for your advice.