OCing GPU

Gumbi

Hi; having read about the wonders that can be obtained by over-clocking the GTX 460 (768mb) I decided to buy this graphics card. It was my first computer build and I am very happy with it.

I am relatively computer literate, but not so when it comes to over-clocking. Having researched how to do so online, I have narrowed it down to these steps. Before I go ahead, can anyone confirm these steps and recommend a good benchmarking tool with which to test the stability of my tweaked card (and how to know if it's stable or not):

1.Tweak my Core Clock setting by increasing it slowly, and benchmarking each change up to the point where the benchmark fails, and it is here that I set my Core Clock setting to its highest stable setting.

2. I then reset the Core Clock setting and carry out the same tests with the Memory Clock Setting.

3. I then set both of these up to the level where they were both stable.

And now for some questions:

-Am I missing anything?
-Do I ignore the Shader Clock Setting?
-Would anyone be so kind as to link me to a good benchmarking suite, and explain how to apply in this instance i. over-clocking.

Here are my current idle temps. and info. and a screenshot of my current (unchanged) memory settings (as shown by VTune):

http://s991.photobucket.com/albums/af34/tommymooore/

Thanks very, very much in advance.

Solitaire

Those are stock speeds its showing.

- Not really, although some boards can additionally interface with the card's voltage controller, giving you the option to overvolt the card to a degree. The result is much like CPU/memory OCing, although many cards strictly limit the amount of extra voltage you can pump in to GPU and memory. This way you can slightly increase voltage once a part loses stability and re-test to see if the higher voltage can keep it stable above speeds achieved at stock volts. The trade-off is, of course, increased heat and power consumption.

- Pretty much. Just make sure it continues to rise 2:1 in relation to core GPU speed, although I think Fermis are locked at the 2:1 ratio anyway :)

- Off the top of my head, try Rivatuner or MSI Afterburner. Depending on brand of card and what voltage controller its using your mileage will vary.

Gumbi

Thanks Solitaire. I can use VTune (shown in the pictures) to tweak the memory frequency. By benchmarking suite, I meant a program that I can run which will basically give me FPS results after putting my card through a test.

Also, how do I know when can't tweak any further? Temperature isn't an issue at all, and neither will power consumption be (I don't think) so which factor might limit my OCing?

And as a confirmation, I tweak both my Core Clock Setting, my Memory Clock Setting, while keeping the Core Clock Setting in a 2:1 ratio to the Shader Clock Setting?

Solitaire

I think the shaders will automatically increase in speed twice as fast as the core clock is increased on Fermi. I think. Core and memory are the things you tweak (and the voltages for each if you can) and you tweak them seperately - you're directly tweaking their speeds, unlike CPU/RAM OCing where you're really tweaking the mobo

Basically, once you keep getting glitches in FurMark or games its time to step back a bit and either finish up or boost voltage if you have that option and don't have heat/power constraints. If you are overvolting and there's no obvious limit to what you can set it to then do some research and find out what realistic voltage ceiling you have before life expectancy or reliability begin to plummet

As for benching...

- 3DMark is a bench

- Some games have integrated benches

- After that there's utilities like FRAPS, but their compatibility isn't universal and they can be a performance hit in and of themselves

Gumbi

Solitaire wrote: »

I think the shaders will automatically increase in speed twice as fast as the core clock is increased on Fermi. I think. Core and memory are the things you tweak (and the voltages for each if you can) and you tweak them seperately - you're directly tweaking their speeds, unlike CPU/RAM OCing where you're really tweaking the mobo

Basically, once you keep getting glitches in FurMark or games its time to step back a bit and either finish up or boost voltage if you have that option and don't have heat/power constraints. If you are overvolting and there's no obvious limit to what you can set it to then do some research and find out what realistic voltage ceiling you have before life expectancy or reliability begin to plummet

As for benching...

- 3DMark is a bench

- Some games have integrated benches

- After that there's utilities like FRAPS, but their compatibility isn't universal and they can be a performance hit in and of themselves

OK. I'll tweak the the mem. and and core. settings a bit, and give a small, corresponding boost in voltage. (Using the programs that you mentioned). Can you give me an idea of a rough ratio for increasing the frequency and voltage? Or will I boost the frequencies alone, and when I start hitting glitches, boost the voltage?

I'm sure if I find reviews etc. online, where they use OC this card, I can use their numbers and play it safe and us numbers a bit lower than the ones they attained.

Thanks. you're very helpful.

Solitaire

Gumbi wrote: »

when I start hitting glitches, boost the voltage?

^ That

Gumbi

So the only limiting factors are heat, power, and, I'm assuming I can only over-volt the GPU so much? I will have to find some numbers that will tell me what is a reasonable voltage to use. (I'm not trying to reach the GPU's absolute maximum potential, I just want to get a little bit more for my money, that's all). To be honest, the card is extremely cool, idling at 22-24 degrees Celsius (according to CoreTemp) and peaking at 60.

Solitaire

CoreTemp is showing you your GPU temps??!?

Gumbi

Solitaire wrote: »

CoreTemp is showing you your GPU temps??!?

Woops, I meant VTune. Musta zoned out for a sec