So, I finally got my setup working and found that my cards didn't even hit 50°C with a max overclock of ~1250MHz
I found a BIOS for the 670 FTW model with 1.21V to update with.
I saved an original copy of the BIOS using GPU-z, lying on the desktop, and I installed the new BIOS with some program I found (Icon looks like something on fire). I couldn't get any higher overclocks so I thought I should restart the pc and guess what. This appeared:
 

 
So, I found this site and jumped to step 4 and made a bootable USB. Then I rearranged my graphics cards so that I've got a good GPU in the first slot and the bad ones down below and flipped the switches on my ASUS Rampage IV Formula motherboard:
 
   
 
But then after entering the command line (after I found the US layout on my danish laptop) I got this:
 

 
"No Nvidia display adapters found"
And all of the white text flashed constantly, so that's why there are no green/purple lines on the screen.
 
Am I doing something wrong? I really hope I didn't break anything.

Here is what I suggest. Borrow a known good NVIDIA based card (other than a GTX 670) and use it to boot. Once you're are in the operating system and you've confirmed everything is working shut down the PC. Insert the known bad card into the 2nd or 3rd PCI-E slot. Start the PC and make sure it is recognized in the device manager. If so then use the procedure here to flash your BIOs back to the correct one. That assumes it is an EVGA card:   
http://forums.evga.com/fb.ashx?m=1703680

flagstang

rjohnson11
Here is what I suggest. Borrow a known good NVIDIA based card (other than a GTX 670) and use it to boot. Once you're are in the operating system and you've confirmed everything is working shut down the PC. Insert the known bad card into the 2nd or 3rd PCI-E slot. Start the PC and make sure it is recognized in the device manager. If so then use the procedure here to flash your BIOs back to the correct one. That assumes it is an EVGA card:   
http://forums.evga.com/fb.ashx?m=1703680

I've got a GT240 installed in slot #1 so I can boot alright. I can see all cards in the BIOS, but only 2 in device manager. I hope that I could flash the ones in device manager and then I'll be able to see the third card.


I can't follow the instruction in the linked thread because there's no 670 FTW firmware. However, I downloaded the Superclocked anyway and it won't proceed once I click the exe file.

And to the rest of you guys listening, all I can say is that this has got to be - by far - the worst thing I've ever done in my entire gaming career. I'm not the smartest one am I?

 
This is just a case of ignorance, not stupidity. Now if you repeat this in the future, it will be stupidity. Hell, when I first started building my PC, I didn't put the rubber protectors on my heatsink and went through 4 mobo RMA's, 3 RAM RMA's and a gpu RMA before I learned it was that. We all make mistakes... This is just may be a... Costly one....

maniacvvv
OMG
Unbeliveable, your cards were perfect!
One of the worst novice mistakes I have ever seen.

You do understand that your warranty from EVGA is now 100% VOID with such a BIOS on the cards.

You can only hope that a videocard BIOS -expert- will personally help you try and force flash the original stock BIOS. 

Good luck, you are really going to need it.

Step one. Turn off the system.
Step two. Dont read guides that are 3 years out of date.
Step three. You have about 10 hrs of reading ahead of you, pay ATTENTION to the dates of what you are reading, pay ATTENTION to the cards that are being used, and do NOT use ANYTHING but the latest known working programs for Kepler cards and BIOS's--> THAT ARE UP TO DATE 
Step four. Pray that a expert will help you

 
I forgot all about the date , that's the thing I hate about the internet - nothing is ever purged
You make me feel like a moron, which... is probably right in this case. I'll never do it again, I swear 
 

rjohnson11 
You said there is no 670 FTW firmware? I see it quite clearly in the link I gave you: 

02G-P4-2678-KR - EVGA GeForce GTX 670 FTW 

http://cdn.evga.com/BIOS/2678_80.04.4B.zip 

 
Oh, I completely forgot - it's 3x 4GB cards

Part number: 

04G-P4-3673-KR

There, I fixed it.
Using the version of NVflash posted above and looking in the manual, I found that if I used --index=ask I could get my adapters shown which was 1, 2 and 3.
 
Commands used:
nvflash --index=1 -5 -6 gk104.rom
nvflash --index=2 -5 -6 gk104.rom
nvflash --index=3 -5 -6 gk104.rom
 
Everything is working just like before now, I will have to remember NOT to flash any GPU bios again - too darn expensive in case of failure thereof.
Motherboard bios is another story - there's 2, and if one fails, I'll just copy the good one to the bad one.

maniacvvv

flagstang
There, I fixed it.
Using the version of NVflash posted above and looking in the manual, I found that if I used --index=ask I could get my adapters shown which was 1, 2 and 3.

Commands used:
nvflash --index=1 -5 -6 gk104.rom
nvflash --index=2 -5 -6 gk104.rom
nvflash --index=3 -5 -6 gk104.rom

Everything is working just like before now, I will have to remember NOT to flash any GPU bios again - too darn expensive in case of failure thereof.
Motherboard bios is another story - there's 2, and if on fails, I'll just copy the good one to the bad one.

Good recovery, great job bro

Now, KNOCK it off with doing stuff to things that are working fine OK
What you should be doing is testing temps and stability on the new build

Exactly, my temps on the GPU's didn't hit 50°C at any time during any kind of stress test with a max clock of ~1250 MHz
Which made me flash the bios in the first place to get some more juice of it. 
Overclocking the CPU to 5 GHz was a walk in the park. It's using 1.5 volts now (readings, not values) and I could probably go lower. Temps = 80°C using prime95

flagstang

maniacvvv

flagstang
There, I fixed it.
Using the version of NVflash posted above and looking in the manual, I found that if I used --index=ask I could get my adapters shown which was 1, 2 and 3.

Commands used:
nvflash --index=1 -5 -6 gk104.rom
nvflash --index=2 -5 -6 gk104.rom
nvflash --index=3 -5 -6 gk104.rom

Everything is working just like before now, I will have to remember NOT to flash any GPU bios again - too darn expensive in case of failure thereof.
Motherboard bios is another story - there's 2, and if on fails, I'll just copy the good one to the bad one.

Good recovery, great job bro

Now, KNOCK it off with doing stuff to things that are working fine OK
What you should be doing is testing temps and stability on the new build

Exactly, my temps on the GPU's didn't hit 50°C at any time during any kind of stress test with a max clock of ~1250 MHz
Which made me flash the bios in the first place to get some more juice of it. 
Overclocking the CPU to 5 GHz was a walk in the park. It's using 1.5 volts now (readings, not values) and I could probably go lower. Temps = 80°C using prime95

 
Exactly 
50c on the GPU's and 80c on the CPU... those temps are NOT what you would expect to see under water.
For the GPU's given your 3way setup, maybe...
But that CPU at 80c, thats just a terrible temp for watercooling at only 5ghz
-->You need to dope out your cooling and look for issues (bubbles, flowrates, fans) 
 
You -really- need to do a mods rigs page or a hardware sig, so people can know what config you are running
 

Baltothewolf



Really? I thought the ivy bridge's ran super, super hot when overclocked...

Yeah that sounds cool to me on an ivy bridge.
edit: if it is one

It is a Sandy Bridge E processor though

80 is too hot even for SB-e