Originally Posted by Kranik
So I've read quite a bit of this thread but I've got a couple questions:
I've recently picked up two GTX 780 Classifieds and have been testing them pretty heavily, together and separately, and I've noticed some quirks I guess you'd say? Both of my cards have very high ASIC scores, just over 79% which is a good thing from what I've gathered; however, one of the two cards is only capable of a +120Mhz core clock even when I supply extra voltage in Precision X while running the EVGA LN2 BIOS. Now, I thought maybe it was heat related so I went ahead and tested it on its own without the second card impeding air flow and even when the card runs under 65c it'll artifact in Heaven and crash outright in Futuremark Ice Storm. If I drop to +115Mhz core clock it'll still artifact in Heaven but it makes it through runs in Futuremark Ice Storm without issue. Even if I max the voltage in Precision X I see zero improvements in core clock overclocks. The second card is capable of slightly higher core clock overclocks but even when kept under 65c it also artifacts and crashes.
Obviously the silicon lottery plays a big part in this and +120Mhz/+300Mhz overclocks are nothing to scoff at; however, I feel like I should be getting better returns with these cards. Does the Precision X voltage increase actually do anything? Would I benefit from SKYN3T's LN2 BIOS? I do plan to water cool the cards I know with cards like these heat can play a big part in how well they clock but I don't seem to be having heat issues insofar as I can tell. Should I expect gains when I finally put the cards underwater given the results I'm seeing? Am I thinking too hard on this?
You can use AB and Precision X to change voltage, but only up to 1.212v. But I agree with @Jimhans1
, use the Classy Voltage Tuner in the OP.
Since you're using a stock BIOS, we don't know what your clocks are when you say "+120" since you're using a boost BIOS. If you really want to see what your cards are capable of, then flash the skyn3t BIOS to your LN2 BIOS.
If you're cards are Rev. A1, then you can use Rev.3 skyn3t BIOS. If you have Rev. B1 cards, you can use skyn3t Rev.4 BIOS.
To save your stock LN2 BIOS, you're going to need NVFlash v5.142:
Then open up a command prompt and in the command prompt go to the directory where you have NVFlash. For ease of use I always just put it in C:\Classified:
(This will disable the bios protection in order to save or flash a bios)
Nvflash --save call.it.what.you.want.rom
(This will save the stock bios or vbios)
Don't use GPU-Z to save bios, some versions may save your bios corrupted.
For flashing a new BIOS:
Unpack the bios you want into C:\Classified (the same folder where NVFlash is). Then while in that folder right click in an empty space and select "open command window here" or run a command prompt from the start menu and then proceed with the unlock command below and the rest of the commands as needed.
nvflash -4 -5 -6 biosname.rom
You might have to hit "y" twice. Once it says completed reboot. You might also have to reinstall drivers depending on bios.
Flashing with 2 cards installed -
nvflash -i0 -4 -5 -6 biosname.rom - (This is for card #1)
nvflash -i1 -4 -5 -6 biosname.rom - (This is for card #2)
For stability just bench (Valley, Firestrike, Heaven) and play games.
For seeing how your cards stacks up against others I like going to the Valley and Heaven threads. There area spreadsheets in the OP with scores, though they are bench stable and probably not game stable. I have a pretty decent SLI score in there but it was artifacting during my Valley run.
Everything you need (except for a newer version of NVFlash) is in the OP of this thread including the Classified Voltage Tuner (direct download from here: http://www.overclock.net/attachments/19143
Good luck! Edited by coelacanth - 3/5/14 at 12:15pm