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Overclocking the 680 GTX - Help needed!

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May 6, 2016
Hello everyone,

Background: After having some fun with overclocking the CPU and getting good results, I thought that now might be a good time to overclock my GPU as well.
My GPU is the Zotac 680 GTX, no factory OC, and no unique cooler (just the stock blower). The blower thing makes plenty of noise, but I can live with it. I have ensured good air circulation around the GPU: There's a side fan, an intake fan right near the entrance to the blower, and another intake fan right above the GPU.

The Overclock: So I downloaded MSI Afterburner, created a custom fan profile, and then started playing around with the configurations. The first thing I've done is to increase the "Power Limit" slider to the max, which is 132%. Then I increased the Core clock by +100MHz, and the Memory clock by +300MHz. The gains: About 8 more FPS on Furmark and 3-5 more FPS on Witcher 3. Not huge by any means, but an improvement.

In order to test the stability of the new GPU configuration, I went on ahead and ran Valley benchmark for over an hour. It didn't crash or anything like that, and the temperatures were somewhere between 72-74c. Immediately after that, I seized the (Heat :p) momentum and ran FurMark for 20 minutes or so, and the temperature peaked at 78-79c. Again, no crashes.

I played Witcher 3 for about an hour or so, and the GPU temperature was again between 72-74c. Ran great, no crashing.

My Questions:
1. Is this overclock considered "Mild", or am I pushing the card to it's limits?
2. Are there any major risks in what I've done? Am I more likely to wake up one morning with a bricked GPU, or have a scary crash during a game?
3. Were my stability tests reasonable, or was there anything else I should have done?
4. Are those temperatures OK for the 680 GTX?

Thanks for the help! A newbie :cool:
1. Its a solid overclock.
2. Nope and nope.
3. Perfectly reasonable... but I would ditch Furmark and stick with Valley for temperature and stability testing. Furmark is a "power virus".
4. Temps are fine in game.
1. Its a solid overclock.
2. Nope and nope.
3. Perfectly reasonable... but I would ditch Furmark and stick with Valley for temperature and stability testing. Furmark is a "power virus".
4. Temps are fine in game.
Hey dude, thanks for the comment! I have a few additional questions, if I may!
1. From what I read, the only threat to an overclocked GPU is the heat generated by the higher clock speeds and voltage. However, isn't the motherboard strained by a GPU overclock? Does an overclocked GPU draw it's additional power from the motherboard (PCI-E slot), or from the external PSU connections (2x 6 pins)?
2. It somewhat continues the previous question, but does the motherboard even "feel" whether the GPU is overclocked or not? (Unlike, say, FSB overclocking)
3. Any temps I should watch out for? It seems that the official data about this card is that it smokes at 98c, but what about heat damage done over time (say due to thermal expansion and deflation due to heat then cooling down)?
4. In terms of longevity, is there a difference between leaving the card at it's overclocked configuration all the time, to switching between OC and non-OC profiles? For example, letting it boot with no OC, and leave it like that until I choose to play a game, where I will then load the OC profile.
I'm just not entirely sure that turning something on-and-off is safer than simply leaving it on, though I'd like to hear the opinion of someone more experienced than me.

Thanks again dude! I appreciate the help!
1. The motherboard is not strained, no. It takes most of its power (though some does come through the PCIe slot, up to 75W) from the connectors.
2. Nope.
3. Keep it under that 90C. Otherwise, no worries really.
4. I wouldn't worry about it. Either overclock it, or leave it alone. Its not worth your effort, as minimal as it may be, to leave it at stock and then overclock when needed. If you haven't noticed already, the card clocks down on the desktop to 2D clocks and voltages anyway.