I have my GTX 570 running on manual fan control and running between 40C and 50C so I want to try a little OC. I've read advice in these forums about what to tweak first and by how much but I can't find it or remember. Right now my clocks are:

Processor: 1484 MHz
Graphics: 742 MHz
Memory: 1900 MHz

IIRC one should boost the processor clock first? What is a reasonable boost in my case... 1%, 2%, 10%? And if tasks then start to fail one should tweak the memory clock up a wee bit too? Or am I getting this confused with OCing CPUs (which I have never done either, btw, just read about it)

I've also read here that it's difficult to regain time wasted by OCing too much and getting compute errors and results that won't verify so I intend to take this slowly and cautiously.

I have my GTX 570 running on manual fan control and running between 40C and 50C so I want to try a little OC. I've read advice in these forums about what to tweak first and by how much but I can't find it or remember.

Right now my clocks are:

Processor: 1484 MHz
Graphics: 742 MHz
Memory: 1900 MHz

IIRC one should boost the processor clock first?

What is a reasonable boost in my case... 1%, 2%, 10%?

And if tasks then start to fail one should tweak the memory clock up a wee bit too?

Or am I getting this confused with OCing CPUs (which I have never done either, btw, just read about it)

I've also read here that it's difficult to regain time wasted by OCing too much and getting compute errors and results that won't verify so I intend to take this slowly and cautiously.

How possible do you think overclocking is on a GTX 670, I've heard Nvidia locked the voltage. Is it better to simply run stock to avoid WU failures?

OK, then the plan is as follows:

First you could increase your GPU clock rate by 10%, and the GPU voltage by 50mV. If it's stable, you can increase your GPU clock by 10MHz increments as long as it stays stable (crunches without errors for a week). Then you should follow the stability regain procedure I've described above. Note that different workunit batches tolerate different overclocking, so if your overclock settings have no "safety overhead" (ie. a little higher GPU voltage than needed, or a little lower GPU clock than the highest your GPU can run at the given voltage), then you should recalibrate your overclocking settings when tasks start to fail.

nvidia-settings -q all | grep vcore
nvidia-settings -1 all | grep volt

nvidia-settings -q all > queries.txt

How possible do you think overclocking is on a GTX 670, I've heard Nvidia locked the voltage. Is it better to simply run stock to avoid WU failures?

I Googled "Linux overclock nvidia" and found many articles stating Fermi cards cannot be overclocked on Linux. Unless things have changed with the 313.x driver I think I must conclude the only way to overclock nVidia with Linux is to hack the card's BIOS similar to the way it's described here. Note they did the hack on a GT220. What's the odds of it working on a GTX570? Has anybody done this successfully?

I found a really great OC guide that I was reading. I don't know how much it will help, but I will post it anyway. It does touch on the power measurement, and includes, at the end of it, links to OC guides for specific vendor cards like the Asus 670 DC2T and what not.


http://www.overclock.net/t/1265110/the-gtx-670-overclocking-master-guide

I found a really great OC guide that I was reading. I don't know how much it will help, but I will post it anyway. It does touch on the power measurement, and includes, at the end of it, links to OC guides for specific vendor cards like the Asus 670 DC2T and what not.


http://www.overclock.net/t/1265110/the-gtx-670-overclocking-master-guide

I was then able to OC the GTX660Ti to 1250MHz
My GPU says 1111MHz is the Boost rate (a 5% FOC), so 1250MHz isn't too much more (12.5% over the FOC) - it might work here, as long as I keep it below 70°C (which shouldn't be an issue with the GTX470 pulled, for now). I do like the idea of a GTX660Ti matching a stock GTX680

If starting a thread confers ownership of it then I could say I own the thread but I don't think that way. As far as I am concerned you're on topic here, FWIW. Heat issues and overclocking are all part of the same topic in my mind.

I've done a fair bot of work on the heat and temperature thing, I think. On Linux I cannot get the fan to go any higher than 85% and several other sources indicate that is the max allowed by nVidia in the BIOS. Windows may be different but you may be able to squeeze another 5%. I've noticed if I set the fan to 100% it will fall back to ~45%. If I set it to 85% it will fall back to ~50% which is very weird but the point is if you set it to just the right number it will fall back to 85%, at least that's the way it works on Linux.

I doubt an additional 5% will keep your card under 70C if ambient room temp is 26. I don't have any graphs or tables to base this estimate on but from a little tinkering and observing I would say you could get under 70C with an ambient room temp of ~20C. To achieve that 20C you need to consider venting your GPU to the outdoors or into the house attic or any room but the computer room. The alternative would probably be air conditioning.

I have a highly customized cooling solution and I am working on clearing some other tasks from my plate so I can put together a video or series of pics to show how easy it is to engineer and create your own very capable cooling solutions. What you need to do is adapt a piece of duct to the back of your computer case where the GPU vents in order to catch that hot air and carry it away. You can do that easily with a pair of tin snips, a measuring tape and a little knowledge of simple geometry. Actually if you buy common aluminum duct you can cut that with a decent pair of scissors, expensive tin snips not required. To fasten your creation in place you can literally use duct tape and string and glue, or you can drill holes and fasten with pop rivets or screws. You canget a decent drill for about $20 brand new, better deals at the pawn shop if you talk them down and they always go down. If you buy self tapping screws you don't even need to buy drill bits though you'll want them eventually if you have a drill.

Once you have that adaptor the rest is easy... just connect elbows and straight pieces to carry the air out the window or through a hole in the ceiling into the attic, through the floor into the basement, wherever you wish. And you can put inexpensive helper fans into the duct to assist the flow over longer runs though with standard and inexpensive 4 inch clothes dryer duct you need not worry too much about that.

Yeah it takes tools but you can invest in tools and make stuff for yourself cheap or you can blow money on expensive off the shelf solutions that often don't work half as well as something you design to meet your specific need. Whatever creams yer twinky.

Also, I'm considering either hacking the BIOS on the card to allow fan speeds higher than 85% or else rewiring the fan to force it to run at 100% which has obvious benefits and may negate the need for ducts or lower ambient temp. That requires a soldering iron and confidence as you would need to snip wires and resolder stuff on the card. Steady hands helps too :-)

Hmmm, steady hands and confidence... isn't that why the gods gave us whisky?

on all of my 660 Ti cards I used MSI Afterburner and maxxed out the Power Limit slider (113%) and it automatically increased the boost gpu clock. If it is possible to increase the Power Limit I would try that first, as it would (AFAIK) increase the voltage a little bit if needed to reach a higher boost clock.
____________
XtremeSystems.org - #1 Team in GPUGrid

Oh, I've find out, that NVidia forbid the card manufacturers to enable voltage tweaking of the Kepler chips above 1.175V. The MSI Afterburner V2.23 is the last version which supports voltages above this limit. Unfortunately it doesn't support GTX660(Ti).

Is 1.175 volts enough for a decent OC? If not then what is the alternative, is it necessary then to modify the BIOS to get above 1.175?

It should be ok. Search for what other people have achieved with your GPU and see if that is ok for you.

remember that the 660 Ti will "boost" its clock when under high GPU usage. So if you are setting a certain MHz, it will actually go higher than that when under load. The higher power limit will allow that boost to go higher than normal. Something to keep in mind when setting MHz on the core/shader. You may have to decrease the power limit if you are raising the core clock, or lower the core clock if you are raising the power limit.
____________
XtremeSystems.org - #1 Team in GPUGrid