GTX 680 Clock Speeds, GPU Boost, OC's, Temps and Volts

 
Now that I've had one of these in my hands since launch day and had a chance to play around with it some, thought I'd share some of my findings on how these things work and what's relevant and what isn't. It may also help people when first playing around and first OC attempts.
 
Base Clock
Is just that and not terribly important, you are unlikely to see your GTX680 running at this speed as GPU boost cannot be disabled. Most important thing to note is that your GPU Clock Offset in PrecisionX does not relate directly to the base clock as Gpu Boost will boost above this speed and really is just a base reference point.
 
 
Boost Clock
This is somewhat more important, this is typically what you'll see your card running at under load when GPU Boost kicks in. This is also where things get a little bit more vague. Nvidia state that every GTX680 will have a minimum Boost Clock of 1058MHz but as has been the case in the past each card will vary. GPU boost will increase the clock speed of the card in 13MHz increments between 1058 and 1110MHz, so your boost clock on stock settings will be 1058, 1071, 1084, 1097 or 1110MHz.
 
Now Nvidia also state that this number can vary depending upon load, temps, power target and the application being run at the time. However so far this has not been my experience, my boost clock on stock settings is always 1071MHz so I've started thinking of this as my standard boost clock, I notice that many others have a standard boost clock of the max 1110MHz. Whether or not this number actually affects the OC'ing potential of the card, well it's too early to tell at the moment until we get more numbers in, though I suspect it may.
 
Nvidia say that by increasing the Power Target your card should be able to achieve a higher boost clock with other settings remaining at stock. Even with max power target of 132% my boost clock on otherwise stock settings remains at 1071MHz regardless of what I throw at it so I'd be interested to hear if anyone else has found differently.
 
GPU Clock Offset
This setting in PrecisionX basically allows the card to increase it's clock speed above it's standard power profile by whatever setting you enter here. So a +100MHz clock offset should increase your standard boost clock by that amount, so in my case my card will now normally run at 1171MHz under load, though I have observed it running slightly higher as other factors come into play.
 
Power Target
The TDP of the reference GTX680 is 195W and at stock settings the typical power draw is 170W, this is the Power Target at 0%. When you increase the Power Target from 0% to 132% you are increasing the power the card has available from 170w to 225w which is the specification limit for 2 six pin connectors and PCIe slot.
 
Important things to note are that adjusting the Power Target does not directly affect the voltage, and that by increasing Power Target you are just increasing the amount of power the card has available to work with up to the limit of the specification. Furthermore, just because the card has more available power it will only use it if it requires it. So setting to max Power Target in itself is not inherently dangerous and unlikely to cause issues, however once you start increasing clock speeds and power, then heat will rise and the card may reduce clock speeds and/or voltage as a result so there may be a balancing act here once you start hitting the limits of your card.

OC'ing
I'm not going to go into any great detail on OC'ing these cards as there is now enough information out there but as a rough guide:-
 
-Increase power target, Nvidia say that it is perfectly safe to run at Max allowable of 132%
-Increase GPU Clock Offset, +100MHz seems a safe starting point and people are getting success at +200MHz and more but work up there slowly.
-Increase Memory Clock Offset, +250MHz is a safe starting point and people getting success at +5-600MHz
 
Temps
As always lower is better and the advice seems to be try and keep below 70 as above this number your OC potential may be affected, with a fan profile set I have no trouble keeping mine about 60.
 
Volts
By use of the power target feature you are already allowing the card to increase it's power usage, people who have used methods such as external power boards to increase voltage either see no benefit or report reduced performance. So current best advice is to use Power Target rather than forcing increased voltage.
 
General Observations
Different games and applications use different amounts of power in order to render any given frame, in practice this means it's not going to be so easy to find one max stable overclock as what may be stable in one application may not be in another and that one GPU clock offset can produce a different end clockspeed in different applications. As always keeping an eye on temps is key.
 
All in all, this is the fastest, coolest, quietest card I have owned and I'm pretty pleased with it, there may be a lot of talk about this being a midrange part but it's working well for me.
 
Hope this helps some.

nice writeup, thanks. 

thanks for guide man :) this is exactly what I've been looking for.
my boost clock always stick at 1097 Mhz, no matter what game i play.

Great info, ill be using it. Did you by any chance do re-TIM, im curious if it makes much of a difference to stay below that 70c OC barrier.

I would think the 70 degree thing would be fairly simple if these are anything like my 570's.I dont think they have ever seen 70 and thats running at FTW speeds.

Mystikalrush

Great info, ill be using it. Did you by any chance do re-TIM, im curious if it makes much of a difference to stay below that 70c OC barrier.

Glad you guys are finding this useful.

I have not re-done the TIM, as I don't see the need at the moment, my card idles between 30-36 degrees depending upon ambient and is easy to keep load under 70 with a fan profile set. I will be using the high flow bracket when it arrives though.

Mystikalrush

Great info, ill be using it. Did you by any chance do re-TIM, im curious if it makes much of a difference to stay below that 70c OC barrier.

 
I would not re-TIM as there is no heatspreader, just the bare silicon/chip.

Updated original post for accuracy with further information on Power Target and Clock Speeds.

Boost Clock
This is somewhat more important, this is typically what you'll see your card running at under load when GPU Boost kicks in. This is also where things get a little bit more vague. Nvidia state that every GTX680 will have a minimum Boost Clock of 1058MHz but as has been the case in the past each card will vary. GPU boost will increase the clock speed of the card in 13MHz increments between 1058 and 1110MHz, so your boost clock on stock settings will be 1058, 1071, 1084, 1097 or 1110MHz.

 
You are mistaken.
The Boost clock quoted on the reference part pages is not the MINIMUM boost clock, it is the AVERAGE boost clock. There are 3 more boosted clockrates in increments of 13mhz below 1058 before reaching 1006.
 
Nvidia has not put on any of their official pages, wording that implies 1058 is the minimum.
 
Infact, the opposite is written in the official reviewing documentation providied
 

The “Boost Clock” is the average clock frequency the GPU will run under load in many typical non-TDP apps that require less GPU power consumption. On average, the typical Boost Clock provided by GPU Boost in GeForce GTX 680 is 1058MHz, an improvement of just over 5%. The Boost Clock is a typical clock level achieved running a typical game in a typical environment

Thanks for the info! I was a bit confused with all the new features that the 680 has, so this will come in handy when I get mine and start overclocking.