Not getting the OC I expected out of my GPU's

[Crow47]

Hey, everyone. I recently took delivery of a new Seasonic 850 Watt power supply to upgrade from my 700 watt Thermaltake so I could have some headroom and overclock my GPU's. As it stands right now I'm having a lot of trouble getting any kind of overclock stable on my 670's. Prior to going SLI, I was running a 125MHz OC on both the core and memory. Now, even with the upgraded power supply, I can barely manage 50 MHz on the core and memory without getting driver crashes and game crashes left and right. I'm keeping an eye on my temperatures using MSI Afterburner (also what I'm using to dial in the overclocks), and I am absolutely not overheating. I suppose this is where my ignorance with this kind of thing shows, because I just don't understand why I'm not getting better performance out of these cards. 

 

To be clear, the computer isn't crashing or freezing, all my games crash about 5 minutes in and I either get some Direct X error saying the "device has been removed" or I get an error telling me the nVidia driver has crashed and restarted. What can I do to get some additional headroom out of these cards? Something just doesn't seem right, because for everything that I can see my temperatures are fine. At the point I'm at, I'm willing to try something a little more drastic, like a VBios flash, or, if I can't get any reasonable OC out of these cards I'll just put these on eBay and get a 780. 

[Puck]

Test the new card individually and see how it clocks.

 

Your original card may be fine, but there could be an issue with the second card that makes them both crash in SLI.

[IVIYTH0S]

So you're not getting better performance with two cards than you were with one??

[El_Capitan]

1. Make sure your drivers are installed for both cards, preferably with the same drivers. When you add an additional card in SLI, sometimes your OS might auto-install the basic driver set for the new card.

 

2. The GTX 670/680 throttle at semi-high temperatures, like around 80C. I'm assuming you have these cards on air and not watercooled, so the top card might be reaching this temperature and throttling, affecting your performance in SLI, especially if you have their overclocks synced.

 

3. There are two ways to overclock with multiple cards in the same system.

• Have a synced overclock (this is default for MSI Afterburner, so make sure that if you don't want this, to uncheck this option). So if one card gets to 1220MHz Core Clock, and the other can get to 1243MHz, with the same voltage, you'd have them both set to 1220MHz Core Clock.
• Have both optimally set at their own overclock (uncheck this option).

 

Like Puck said, it's easier to test each card's performance individually and note their overclocks. That way when you have them both in SLI, you know what overclock settings they're capable of.

[Crow47]

So you're not getting better performance with two cards than you were with one??

 

Sorry if I wasn't clear, but I'm not getting the overclock I used to when I just had once. Performance is naturally much better with two.

 

1. Make sure your drivers are installed for both cards, preferably with the same drivers. When you add an additional card in SLI, sometimes your OS might auto-install the basic driver set for the new card.

 

2. The GTX 670/680 throttle at semi-high temperatures, like around 80C. I'm assuming you have these cards on air and not watercooled, so the top card might be reaching this temperature and throttling, affecting your performance in SLI, especially if you have their overclocks synced.

 

3. There are two ways to overclock with multiple cards in the same system.

• Have a synced overclock (this is default for MSI Afterburner, so make sure that if you don't want this, to uncheck this option). So if one card gets to 1220MHz Core Clock, and the other can get to 1243MHz, with the same voltage, you'd have them both set to 1220MHz Core Clock.
• Have both optimally set at their own overclock (uncheck this option).

 

Like Puck said, it's easier to test each card's performance individually and note their overclocks. That way when you have them both in SLI, you know what overclock settings they're capable of.

 

I guess this is an indicator of how rusty my knowledge was, but I thought for SLI to work, both cards had to be on the same clock speed. How would individually setting overclocks for both cards help in this case?

[El_Capitan]

 

1. Make sure your drivers are installed for both cards, preferably with the same drivers. When you add an additional card in SLI, sometimes your OS might auto-install the basic driver set for the new card.

 

2. The GTX 670/680 throttle at semi-high temperatures, like around 80C. I'm assuming you have these cards on air and not watercooled, so the top card might be reaching this temperature and throttling, affecting your performance in SLI, especially if you have their overclocks synced.

 

3. There are two ways to overclock with multiple cards in the same system.

• Have a synced overclock (this is default for MSI Afterburner, so make sure that if you don't want this, to uncheck this option). So if one card gets to 1220MHz Core Clock, and the other can get to 1243MHz, with the same voltage, you'd have them both set to 1220MHz Core Clock.
• Have both optimally set at their own overclock (uncheck this option).

 

Like Puck said, it's easier to test each card's performance individually and note their overclocks. That way when you have them both in SLI, you know what overclock settings they're capable of.

 

I guess this is an indicator of how rusty my knowledge was, but I thought for SLI to work, both cards had to be on the same clock speed. How would individually setting overclocks for both cards help in this case?

 

 

Yeah, the cards don't have to be on the same clock speed. Individually overclocking each card and not syncing them would give you the most performance benefit since you're maximizing the performance for each card and not using the lowest common denominator for overclocks. The downside is that you might notice more perceptible microstutter (I could never see microstutter except from two very slow cards, though).One card with a much faster overclock will render frames much faster than the slower card, so you could experience more irregular delays between the frames.

[cchalogamer]

The card's don't have to have the same clock speeds to work, in the past the driver would set it that way, but things have changed. I DO prefer running the same clocks personally as they tend to show stuttering more often when mismatched)

 

I would seriously consider the heat being as issue as all the PNY GTX 670s I've seen have rather shitty coolers (like mine) and don't have much headroom for temps without crazy fan speeds, SLI of course only adds to that for the top card.  I'm, not saying just the core here, everything else on the card will be stressed more (VRMs etc) and parts of the card are used in SLI that aren't in single card operation and might just not play nice.  

 

You really shouldn't have hit any power issues with the 700w PSU either, I can run two GTX 770s (they draw more power than 670s) with the 4770K rig on a 550w PSU you should have had plenty of headroom, and contrary to my dislike of them Thermaltake usually makes at least good PSUs.

 

At the end of it all though with your resolution you might be happier with some games using a card like the 780 with more memory, I know even @ 1080p I can run out with the 770s and processing power starts to be wasted

[wevsspot]

Remember that boost clock, temperature and tdp are all hugely important factors on the Kepler architecture.  It's by far easier to overclock Kepler by un-linking (as mentioned above already) and then tweaking each card individually.

 

Are you getting any BSODs or driver failure only?

[Crow47]

Remember that boost clock, temperature and tdp are all hugely important factors on the Kepler architecture.  It's by far easier to overclock Kepler by un-linking (as mentioned above already) and then tweaking each card individually.

 

Are you getting any BSODs or driver failure only?

 

I'll have to try overclocking them individually. That's just a new concept for me. I'll be interested to test this.

 

I'm getting driver failures and game crashes only.

[wevsspot]

What driver version are you running?

 

Also, Google "The GTX 670 Overclocking Master-Guide"

 

Simply one of the best tutorials I've ever read on overclocking Kepler.

[Crow47]

What driver version are you running?

 

Also, Google "The GTX 670 Overclocking Master-Guide"

 

Simply one of the best tutorials I've ever read on overclocking Kepler.

 

I'm running the latest driver, 335.whatever it is right now.

 

I actually found that guide and followed it to the best of my abilities. I'm not getting JACK out of these cards right now and it's driving me nuts. 

 

Pondering putting these up on eBay and wondering what my most cost-effective upgrade is. 

[wevsspot]

Anything past driver version 332.21 was a bust for me on my GTX 670s in SLi.  Seems like the more they tweak the drivers for the newest cards, the worse they work on the previous generation cards.

 

If it were me I'd roll back to 332.21 or earlier for testing purposes and try eVGA PrecisionX instead of Afterburner.