Using 2 GTX 580's, EVGA, Precision X (4.2.1) for overclocking and fan management.
Specifically, these cards: http://www.newegg.com/Product/Product.aspx?Item=N82E16814130587
Their default is 772 gpu clock and 2004 memory clock, at 1000mv for voltage.
I'm able to get them, at their highest, to 850, 2300, with a 1013 necessary. To me this seems really low. I've tried to hit 900, but can't manage it, as it causes instability in my tests.
For reference, I'm using a modded Skyrim (heavy ENB and around 190 mods) for testing. In the area I test, I get 44fps average, up to almost 50 at my highest overclock. This may be pointless information, but I'm including all I can. On that note, there's nothing else I can do with the rest of the rig as far as performance goes unless I spend money I don't have, so yeah.
Basically, I want to get them higher. I keep a warm room and the hottest they get is 66C currently, so I have room temp-wise for higher clock. Also, I've never bothered before because I simply never needed to. And really, I still don't need to outside of this Skyrim setup I got, which is particularly intense because of what I have going on, but I still want to try.
Any tips?
MOAR VOLTAGE!!! At least according to this thread:
http://www.overclock.net/t/1038321/overclock-gtx-580-reference#post_13827888
I'm wary with messing with the voltage too much. I spent the last half hour polishing it to 875/2300 at stock voltage. I'll try increasing the voltage in steps to see if I can get it running at at least 1000mhz without pumping the voltage up too much, as that's my initial goal.
And correct me if I'm wrong, but doesn't putting the voltage up reduce the life of things? That's namely what I'm worried about, I wont be in the position to get a new card for quite a long while.
Addition: Yeah, can't hit that 900 with higher voltage, went as high as 1063, and I'm just not comfortable going any higher. Guess I'm stuck here until I have money again.
Poor cooling is one factor, blowers are great for keeping the rest of your case cool but do a poor job of cooling the actual GPU.
My EVGA 570 hits those speeds on clocks and 2200 (max) memory speeds but it can't break the 900 barrier either no matter how much voltage is fed to it.
Also, if you're OCing these cards in an SLI config then it's going to only be able to get a very minor OC compared to if the cards were running Solo.
Those are pretty unrealistic expectations. I remember shitting bricks when I got my 560-Ti (Twin Frozr II) up to 945MHz (15% OC), and that GPU was well-known for OCing, with some people breaking the 1 GHz barrier with copious amounts of voltage and a fair bit of luck. Getting a 10-15% OC on a GPU is pretty good; you're expecting ~30%. And yes, voltage adversely affects longevity, but a few mV won't kill ya. Personally, I wouldn't go any higher than 1.050v, but I'd try to keep it even less if you're running in SLI. If you can hit 900MHz, you did a fantastic job (16.5%). Even at 875MHz (~13.5% OC), it's still a pretty good job. If you really aren't getting the performance you want, it's time for a GPU upgrade (or liquid cooling...)
Well cooling isn't really a factor. These things do very well with cooling, and since I live in a cold area, I can just open a window and put a sweatshirt on if they get too hot.
And yeah, I figured my desires were a bit too much. I was able to keep it stable with most games at 875, but the moment I got a driver crash on Chiv, I went down to 825, which I'll probably stay at.
Oh well. I'll consider it a success, since I didn't know that you can't OC these cards like you can a CPU (I've managed 5.0 stable, but worried about longevity so I sit at 4.5), especially on SLI. Even though where I am now, I'll probably be fine clear into 2015.