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GTX 780 Classfied Overclocking Advice?

I

itsmezed

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Joined
Jul 23, 2009
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After much deliberation, I finally settled on the EVGA 780 GTX Classified to replace my old GTX 580. The thing is that while I've dealt with overclocking CPUs quite a bit, I never really tweaked GPUs -- and this one is clearly made for it. Does anyone have any advice or perhaps a link to a guide for overclocking the Classified? Any info on the ins and outs of EVGA's Precision-X utility would be a big help, too.

Thanks! :D
 
What i like to do is max out the voltage and then find my max stable core overclock. Then from their dial down my voltage until it is stable. Memory overclock the same.

There are different methods to doing this but this is how I have done it for years now with success -- AMD and Nvidia. I like to find the max overclock because I know where to go from there. Buying a Lightning or Classified you def want to be close to your max overclock or what is the point of spending thet extra money for a card made for overclocking?
 
Thanks for the reply :)

What increment do you go up by when you bump the core and memory? And is there a reliable way to see what the card is boosting to?
 
What tools do you guys use to overclock and raise voltage? Is there any guides?
 
I was using EVGA's Precision-X but there are other utilities out there. Afterburner is a popular one that comes to mind.
 
Download precision X
Unlink the power and temp targets and max them out
Up the voltage to max (+38 mvh)
Overclock core and memory till it bleeds (I use Valley since it does not hardlock the computer)

Post results on [H].
 
i've found that Crysis 2 really exposes instabilities in your overclock, it seems to be the game that artifacts the easiest. good luck! the classified is a bitchin' card.
 
KickAssCop said:
Download precision X
Unlink the power and temp targets and max them out
Up the voltage to max (+38 mvh)
Overclock core and memory till it bleeds (I use Valley since it does not hardlock the computer)

Post results on [H].
Click to expand...

Will this work on Gigabyte 780gtx?
 
Here's the strange thing: running the Valley benchmark shows the GPU at 1333, but the memory still at 3000 in spite of the memory offset being set at +395.

Update:
It seems Precison-X was showing settings on boot but not actually applying them. After hitting apply, it shows the GPU at 1663 MHZ and Memory at 3458 MHz in the Valley benchmark. Been running it at 1920 x 1080 on Ultra w/ 4X AA.

Update 2:
It also seems that no matter what I put the settings at in Precison-X, the log file for GPU-z is showing base memory speed and a GPU clock of 1110.
 
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After re-installing Precision-X and shrinking the display size OC Scanner so I could see both programs on-screen at the same time, I was able to get more accurate results for GPU speed. It looks like I'm capped at an offset of +168 for the GPU, anything more brings a crash of the OC Scanner in short order. That gets me to 1267 and 1293 MHz on the GPU, depending on if I OC the memory. The memory is sitting at an offset of +425 with no problems -- I haven't tried more yet. No idea if those speeds are good or not. :)
 
Look below for crappy overclocks. Yours is fantastic.
Also Valley reports incorrect clocks. Best way to see exact overclock is to either use OSD or see the clock tracking at the bottom of EVGA precision or Afterburner tracking.

GPU-Z has always been a bit flaky for me in terms of reporting actual clocks.
 
Sadly it isn't fully stable at 1293 :(

After extended running of the OC Scanner it'll drop down to between 1254 and 1241. When gaming, it reverted to stock (1110 boost), so I must have been pulling too much juice. I maxed power (115%) and temp (95) targets, and use the max allowable overvoltage of +63mv. Anything over 1293 isn't stable for more than a minute or so, which makes me think it'd take potentially warranty-voiding voltage.
 
itsmezed said:
Sadly it isn't fully stable at 1293 :(

After extended running of the OC Scanner it'll drop down to between 1254 and 1241. When gaming, it reverted to stock (1110 boost), so I must have been pulling too much juice. I maxed power (115%) and temp (95) targets, and use the max allowable overvoltage of +63mv. Anything over 1293 isn't stable for more than a minute or so, which makes me think it'd take potentially warranty-voiding voltage.
Click to expand...
You will need to have a fan curve that speeds up the fans around 70 C temprature to keep it running stable around 1293. I think if the card is hovering around 1254 that means that upping the fan curve will give you another 20-25 Mhz for a total of around 1275 for normal daily use. Frankly, if I were you, I will bench at 1275 and then revert back to something that is more stable (around 1250 Mhz on the core) for daily use.
 
In games, it hasn't even been doing that much. I'm lucky if it holds at 1201 stable while playing SWTOR. Maybe it's the 67.7% ASIC, which I understand is iffy quality (at best) for an air OC. I'm seriously disappointed and thinking of RMAing it; given the extra cost a good OC is expected (though of course not guaranteed).
 
I have 2 of these. First step: switch to LN2 bios and flash skyn3t's rev3 bios from 1st page on OCN owner's forum:

http://www.overclock.net/t/1411500/official-evga-classified-owners-club

See the readme for exact details but I think he increased voltage in precision to 1.2 max, increased power factor max to 200%, and disabled boost for stability.

Away from home for awhile but I think mine are BF4 stable at 1.2 volt, +100 core, +500 memory. I have elpida chips. Others say Samsung or Hynix are better overclockers. My CPU is 2500k at 4500.
 
Already switched to the LN2 bios. I might give it a try, but I'm not sure I want to mess around with flashing a new BIOS yet. OOB, I was only boosting to 1110, which seems low compared to what many others have gotten. The majority of the reviews for the Classified that I've read seem to get 1293 stable on air using just Precision-X, maybe I'm just unlucky because I'm a fair ways off that.
 
itsmezed said:
Here's the strange thing: running the Valley benchmark shows the GPU at 1333, but the memory still at 3000 in spite of the memory offset being set at +395.

Update:
It seems Precison-X was showing settings on boot but not actually applying them. After hitting apply, it shows the GPU at 1663 MHZ and Memory at 3458 MHz in the Valley benchmark. Been running it at 1920 x 1080 on Ultra w/ 4X AA.

Update 2:
It also seems that no matter what I put the settings at in Precison-X, the log file for GPU-z is showing base memory speed and a GPU clock of 1110.
Click to expand...

Valley reports a WRONG clockspeed. ONLY go by the clockspeed in precision-X or Afterburner, those are accurate. Valley is not accurate and GPU-z may not be. To increase any overclock stability, you will probably need higher manual fan speeds.

Important: nobody mentioned it here but you need to download the classified voltage controller software for the classified 780. Go to the EVGA forum or OCN for information on where to find it. With that, you can up the voltage substantially higher than precision alone will allow you - be careful here though. I'm not sure what the limit is with classified controller but don't go nuts with it. Basically, afterburner and precision x limits your voltage to a very small amount. The classified voltage controller will allow you to pass that - I dunno where to get it but check OCN and the EVGA forums.

With the classified voltage controller you should be able to add 100-200mV, whereas precision and afterburner will limit you to 30mV or so.
 
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Precision-X actually lets me add +63mv, but the card can't hold a stable overclock at that. Even at +38mv, things get a little dicey and I tend to get stuck at 1201 in games, At +25mv, and tweaking the fan curve a little, I was able to hold at 1241. That makes me wonder if I got a limited chip.

It was getting kind of loud, though. Not quite "wonder if I should have saved $150 and gotten an R290 loud", but loud enough.
 
My advice is to flash Sky's Rev 3 BIOS after switching to LN2, then maximizing the voltage. You can always switch back to the stock bios if the flash goes tits up. Honestly after owning 2 of these in SLI, I prefer blower style coolers to ACN. The noise will depend on your custom fan profile, case airflow, and ambient temperature. If your card still doesn't overclock well, take off the cooler, apply new paste and check the pads for each memory module, otherwise don't sweat it. The classy already has a higher core than most 780's. Make it stable and enjoy some games!
 
And it looks like that 1241 that was stable during SWTOR causes CIV V to go blackscreen after a few minutes. That's at +25mv with 115% power target. Any more voltage than that gets increasingly unstable.
 
If you want higher overclocks you need to use manual fan at higher settings (not auto fan) and you need the classified voltage controller. 25mV is nothing for overclocking purposes.

1241 also isn't a bad overclock. I don't know why you think that - that is actually a really freaking good overclock IMO. I wouldn't obsess about hitting an arbitrary "1300mhz" number too much - you can hit that with the classified voltage controller but you're gaining .5 fps in games. Is that worth it? I dunno. Probably not.
 
Well that's the problem -- the board started to get unstable over 25mV. My Precision-X actually offers up to 63mV, but that trips something and the card flat out rejects it. FWIW, I tested Civ-V, and the card was running at 992 -- not boosting at all, in spite of the modest OC I had set. Someone on the EVGA forums suggested K-Boost to lock the frequency, and that immediately blackscreened me.

For what ever reason, the card is wonderfully stable running EVGAs on OC Scanner (at least for 20 minutes at a clip), but the overclocks in games are very hit or miss. While 1241 I hit in SWTOR last night this morning, with the same settings, it caused a driver reset and the card reverted to stock. I was only able to get 1201.

At stock it seems rock solid and fine, although only boosting to 1110. Overclocking -- pretty much at all -- and the drivers inevitably reset anywhere from a few minutes to a couple hours later. And that's with the card temp rarely breaking 70.
 
Not to hijack a thread but I just got my classy yesterday and played around with precision X. Just following the simple advice on here, I couldn't even get my card to even do a minimal OC without eventually seeing black screens or the driver error. The temps dont even get that high. Oh yeah, and lots of coil whine too.
 
kaigne said:
Not to hijack a thread but I just got my classy yesterday and played around with precision X. Just following the simple advice on here, I couldn't even get my card to even do a minimal OC without eventually seeing black screens or the driver error. The temps dont even get that high. Oh yeah, and lots of coil whine too.
Click to expand...

I found some cards that are OC'd already might not be able to clock higher or will have limited headroom.

My 1st 780 would not OC more than an offset of 25 and yet its replacement will do 150 without issues. New card has the new stepping.

I have found temps aren't always the reason an OC fails. My card never goes above 55º under load yet 150 is the max I can set with mv raised. Normally the card sits around 42-45º in game.

How minimal is your OC? The instant black screen and coil whine might be of a concern. Are you within a return policy to swap it out. Might get a better binned card.
 
I keep getting this even at default settings


2e187md.jpg
 
I was having similar problems, Kaigne. Although in my case, it happened when overvoltage was applied.
 
I got rid of precision X and the problems went away. Using afterburner, I can do about +50 on clock and +600 on memory with no voltage control(its greyed out).
 
Kinda odd, though. It's my understanding that both programs were made by the RivaTuner people so you'd think the functionality would be pretty much the same. I'll have to try it out when my replacement card comes from NewEgg..
 
Well I doubt afterburner has much to do with it in and of itself--I think precision x was just screwy for whatever reason.
 
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