How to OC 6950 xfire?

[Waco]

Waco:

 

Don't you think I could run one triple radiator with two cards and the processor?? I think its possible as you have 4 gpu's in your loop? Either way I am going to try one XSPC EX360 and EX120 in the loop with two gpus and if It can handle it then I may try it with three cards.

I have 4 GPUs that use less power than the 2 480s you've got.

[Brutality]

ok thx boinker

 

Does anyone know what the NB voltage is on my mobo, and what I should set it to to achieve stable overclocks on my gpu?

[wevsspot]

PCH voltage feeds the chipset, but since the video cards communicate directly with the PCIe controller on the cpu, I'm confused as to whether upping this value will actually help you o/c your video cards any further. On P67/Z68 the VCCSA and VCCIO voltages apply to everything on the cpu except the processor core itself. So that would include the memory controller voltage, pcie voltage etc. The VCCSA is the system agent and the VCCIO is the actual I/O voltage for the memory controller. Upping the VCCSA voltage should increase PCIe voltage which may help some, upping the VCCIO voltage (memory controller - aka QPI/VTT on the older x58 chipsets) may or may not help at all.

 

With all of this being said, I don't see any harm in upping the voltage on all three to the upper range of safe in your settings. For your board that would be;

 

VCCSA Voltage = 1.01250v

VCCIO Voltage = 1.15000v

PCH Voltage = 1.15000v

[Brutality]

PCH voltage feeds the chipset, but since the video cards communicate directly with the PCIe controller on the cpu, I'm confused as to whether upping this value will actually help you o/c your video cards any further. On P67/Z68 the VCCSA and VCCIO voltages apply to everything on the cpu except the processor core itself. So that would include the memory controller voltage, pcie voltage etc. The VCCSA is the system agent and the VCCIO is the actual I/O voltage for the memory controller. Upping the VCCSA voltage should increase PCIe voltage which may help some, upping the VCCIO voltage (memory controller - aka QPI/VTT on the older x58 chipsets) may or may not help at all.

 

With all of this being said, I don't see any harm in upping the voltage on all three to the upper range of safe in your settings. For your board that would be;

 

VCCSA Voltage = 1.01250v

VCCIO Voltage = 1.15000v

PCH Voltage = 1.15000v

 

Thanks, I will try that in the near future, I've decided to first find my highest OC without any voltage tweaking, but after that I will try to increase these voltages to see if I can get a higher OC

 

Seems like the max stable core OC is 904MHz (905 survived for 45mins in trackmania, but I'm gonna play trackmania for 1 hour with 904 now, to see how it goes)

But what I really wanted to ask is, isn't there some general formula regarding the "safe-downclocking", instead of saying: "when you reach max stable OC kick things back a little", it would be nice to know either a % of decrease or a fixed value, like 5 or 10

I.e. if I find my max stable OC to be 904, I either decrease it by.. say 1% ----> downlock to 894MHz, or if it's a fixed value, like 5 or 10, then I downlock to either 899MHz or 894MHz... or if 4 is fine, then it's 900

 

My point is, as a computer scientist / mathematician, I hate ambiguity, and I prefer formulas

So that I don't have to keep asking: If it's 904, how much should I downclock?

or now it was 903 apparently, how much should I downclock, etc. etc.

 

Cheers

 

I really think it's 904 though, but let's see, cya in an hour =)

EDIT: gaaaaah 904 didn't work either.. going for 903 now, cya in an hour (figured I might as well test with 1 hour of trackmania first, since this is where I have the crashes.. instead of wasting 1hr and 10 mins testing with kombustor, heaven and unigine only to see a crash in trackmania)

EDIT2: :O :O

903 didn't crash for 1 hour in trackmania

But now it's soon 0.30am, and i got school at 8.. so I'm gonna go sleep now, but when I get back from school I'm gonna put it through Cinebench OpenGL test, 30 mins in heaven, 30 mins in kombustor and 10 mins in 3dmark 11 test 4 (looped), and play crysis 2 for 1 hour, and browse youtube for 1 hour (I think I had a 0x116 whilst watching some youtube video in fullscreen at 907 on the core or so.. so that's gonna be a test too), and if I've sparetime I'll play Worms Reloaded for 1 hour (practice for S7LAN and some test.. although it's a 2D game and I doubt it will act as a test)

So I am 95% sure 903 is the final clock for the core, now I can ask: to which frequency should I downclock it, to satisfy safe-mode downclock? =)

 

Cheers! woohoo so happy I finally (most likely) found a max core clock!

Edited November 9, 2011 by Brutality

[Stonerboy779]

Hey brute I have discovered that tm fails with new drivers. I was paying a few hours picking up a gold in 75% of the nations tracks and in that time I had display drivers crash and recover 30times always changing menus.

[Brutality]

Hey brute I have discovered that tm fails with new drivers. I was paying a few hours picking up a gold in 75% of the nations tracks and in that time I had display drivers crash and recover 30times always changing menus.

 

I didn't have any problems at stock speeds, and I played for a little over an hour without any crashes at 903 core clock

 

But, assuming 903 is the max stable core clock, how much should I downclock it?

Edited November 10, 2011 by Brutality

[Stonerboy779]

I didn't have any problems at stock speeds, and I played for a little over an hour without any crashes at 903 core clock

 

But, assuming 903 is the max stable core clock, how much should I downclock it?

I will say a round 900 just looks nice in a sig ect.

 

What's your trackmania username I will race ya now if you want?

[Brutality]

I will say a round 900 just looks nice in a sig ect.

 

What's your trackmania username I will race ya now if you want?

 

Uhm either Brutality or 13Brutality37

Can't remember off the top of my head

 

Thanks alot mate, will put it 900 after I run through the last tests =)

 

And then... time to OC that memory biaaaaatch

[Stonerboy779]

Uhm either Brutality or 13Brutality37

Can't remember off the top of my head

 

Thanks alot mate, will put it 900 after I run through the last tests =)

 

And then... time to OC that memory biaaaaatch

Added 13Brutality37 waiting for confirm of to go play some polishpeople

 

good luck with mem oc

[wevsspot]

My point is, as a computer scientist / mathematician, I hate ambiguity, and I prefer formulas

So that I don't have to keep asking: If it's 904, how much should I downclock?

or now it was 903 apparently, how much should I downclock, etc. etc.

Hey Brute -

 

Take max stable clock

Subtract 10Mhz

Round to the nearest even number

Divide by 2

Multiple by 200%

Equals good 24/7 clock

 

[Brutality]

Isn't

Divide by 2

Multiple by 200%

rather redundant?

 

So basically just subtract 10MHz and round to nearest even number? What do you mean by even number? 903-10 = 893 --> 894 or 892 or 890 or 895?

And.. in case of last digit being 5, like 885... do you go high or low? 880 or 890? (if you round by tens)

 

EDIT: GOD DAMNIT

Final test was 1 hour Crysis 2.. and guess what.. it crashed after 5 minutes.. sigh 0x116

at stock clocks I played for a little over an hour, no problems.. so the overclock is just too high, damnit

Man I can't belive it... 30 min heaven and kombustor stable.. 10min 3dmark 11 test 4 stable.. 1 hour trackmania stable... 1 hour youtube stable.. then crysis 2.. crash after 5 mins.. jeeze!

Might as well test with crysis 2 first.. what a waste of time

Edited November 10, 2011 by Brutality

[Waco]

Isn't

 

rather redundant?

 

So basically just subtract 10MHz and round to nearest even number? What do you mean by even number? 903-10 = 893 --> 894 or 892 or 890 or 895?

 

EDIT: GOD DAMNIT

Final test was 1 hour Crysis 2.. and guess what.. it crashed after 5 minutes.. sigh 0x116

at stock clocks I played for a little over an hour, no problems.. so the overclock is just too high, damnit

I'm fairly sure he was kidding about the "formula".

 

Personally I tend to find my max stable clocks using Kombustor with the safety options disabled - then if I ever encounter a video-related crash I'll drop back by 10 MHz each time I run into one.