Overclocking 7600GT

[savage1987]

I've got as far as toying with the core and memory clock speeds in RivaTuner.

1: The issue I am having at the moment (no doubt the first of many) is getting ATITool 0.26's artifact checking to work.

The following error message appears:

-------------------------------------------------------------------------------
The video card you selected for overclocking in ATITool does not seem to be used by Windows.

Visual testing has been disabled.

To fix this, go to Display Properties, Settings and enable the monitor output of the card.
-------------------------------------------------------------------------------

I assume this to be a problem with ATITool or a setting that I do not know about, as I'm sure I wouldn't be trying to overclock the card if it weren't used by Windows.



2. Also, when it comes to toying with the clock speeds (stock cooling, heat pipe, no fan) what should I be increasing first, core or memory, or both at once incrementally?



3. Something else I would like to broaden my understanding of is the function of the core clock and the memory clock speeds - how do they differ in visual impact/results?

I have seen this question asked many times but don't think I've seen an answer. The only thing I have gathered so far is that when using a stock cooled card, memory clock probably isn't going to be safe as high as it might otherwise, due to it not having the same (any?) grade of heat sink as the GPU.


As I said, I am a complete beginner at this, so any and all help is greatly appreciated!!

Thanks
Sam

[savage1987]

What I have done so far is raised the core clock incrementally and run 3dmark05 in between, keeping an eye on temps and waiting for a fault. I found one, at 612/700 I got an error message so I backed the core clock down to 609 and am running the test again.

My logic is this: once I find the highest level of core and memory clock speeds that 3DMark05 will take at a happy temperature, I can then move on to stress testing with a few different games for longer periods of time and see how stability/temperatures go.

Sound reasonable?

BTW, my computer is lacking sorely when it comes to 3DMark05's (and especially 3DMark06's) CPU tests. ~3-7 fps seems to be the norm. Does this sound right?

Sam

[savage1987]

I don't understand why 3dmark05 keeps failing even when I have increased the memory clock by so little. Am I missing something or is this just due to heat in the card? If so, how did these guys manage a final config of 625/805?? Gigabyte GeForce 7600 GT 256MB Review - www.sharkyextreme.com

Something I noticed that I have done differently is this: "The first step is to let the NVIDIA drivers to determine the "optimal" clock speeds, which in the case of the Gigabyte GeForce 7600 GT 256MB, resulted in an extremely nice setting of 603 MHz core and 1.59 GHz memory speeds." Should I have done that, and if so, how do I go about it??

Sam


EDIT: I now realise that each card will overclock do different safe levels, no two are exactly the same - which is weird, they're a bunch of hardware bits stuck together in very much the same way

[roon_VR]

(this is mainly aimed at question 2 in your first post)

The way I went about overclocking my graphics card and to get the best possible core and memory clocks is to slowly increase them incrementally like you've stated in your post. The proper way to overclock your graphics card is to START by raising the memory clock by 5 mhz increments with 3Dmark tests in between. When you've reached to a point where you start see little artifacts throughout the test, you've reached the limit your graphics card can whithold. Once you've found the optimal memory clock, slide it back to default and repeat the process with the core clock. Slowly raise it by 5 mhz increments and stop when you start to see artifacts in the test. Once you've found the maximum memory and core clocks for your graphics card, run a test with both of them at these clocks and determine if it's stable. The 7600GT isn't really a great graphics card to overclock, plus it's a very old. You could pick up a much better graphics card at a reasonable price.

Based on my experience with overclocking video cards, it's not really worth it. You hardly see a difference in gameplay improvements plus you run the risk of overheating your GPU. But, it also depends on which GPU you are overclocking. Some GPU's respond well to higher clock speeds as opposed to other GPU's (for instance, the 7600GT you're using) that react poorly which ultimately condones instability with even the slightest increase in the memory and/or core.

[savage1987]

Yeah, so far I am just using this as an experiment, to see what sort of boost I can pull out of the older hardware. The heat pipe cooling isn't doing me any favours, although even running at 609/700 (up from 560/700 stock) it will last 10minutes of Furmark easily, and sit stable at 82 degrees, so I am a little impressed by it.

When the tests in 3DMark05 were listed as 'FAILED', it didn't get around to artifacting, instead throwing up a "packet lost" or something error message dialogue box against a black screen.

Tomorrow I will put the core back to default and play with the memory clock, see where that gets me.

I'm having thoughts about Vmod'ing the card to see if it kicks up the stability at higher speeds before it breaks and I resign to getting a second hand 8 series or something.

Thanks for the info more is always welcome!
Sam

[roon_VR]

May i ask what your system specs are? 82 degress is not bad under load as long as you don't hit over the 90 degree mark. In regards to "packet lost", I'm guessing you're GPU is getting bottlenecked by your CPU, but i'm taking a complete stab in the dark there.

If you have a crap CPU, maybe try overclocking that a little bit as well and see if you can achieve higher benchmark results?

[savage1987]

Pentium D CPU 2.80GHz
1.00 GB DDR2
Windows 7 Home Premium


System
Manufacturer -- RS400_
Model -- AWRDACPI
Total amount of system memory 1.00 GB RAM
System type -- 32-bit operating system
Number of processor cores 2
64-bit capable -- Yes
Graphics
http://www.sharkyextreme.com/hardwar...211_3628156__1
Display adapter type NVIDIA GeForce 7600 GT (Microsoft Corporation - WDDM)
Total available graphics memory 511 MB
----------- Dedicated graphics memory 256 MB
----------- Dedicated system memory 0 MB
----------- Shared system memory 255 MB
Display adapter driver version 8.15.11.8593
Primary monitor resolution 1920x1080
DirectX version DirectX 9.0 or better (DirectX 10 in fact)

[savage1987]

Stumbled across this, which I think is my next step..
7600gt Volt Mod with A pencil - Overclock.net - Overclocking.net

Now assuming that my Gigabyte card has the same PCB (I think it's a safe enough assumption) I can pop it out and get to work!


Running Furmark for 10minute sessions yielded the following:

560/700 stable at 79degC
609/700 stable at 82degC

So I figure a voltage mod may help with further gains at minimal risk as long as I keep an eye on temperatures.

My only worry is that currently my limit is set at 609/700 not due to artifacting, but due to 3DMark crashing and throwing a "packet lost" notification against a black screen.

[savage1987]

Well, I got ATITool working, it was a simple matter of getting the 0.27 beta version.

So far I have settled on a stable overclock on stock voltage at 602/746 up from a default 540/700. Not too bad I think, but I will try to pull some more out of it with further testing. Otherwise it's Vmod time

[sweefu]

Hey mate,
was just wondering what the specs of the other components in your computer are? just interested.
Cheers.

[savage1987]

Pentium D 820
1GB RAM, not for long tho
a nice 22in widescreen high def LCD

I think that's the main bits