Getting started was a little bit tricky, coming in late to the 7970 game. This How-To shows, using just Afterburner, how to get into overclocking the 7970, and removing some of the limits imposed by the drivers/registry. There are a few ways to go about doing this, one or two patches floating around etc, but this is just the what I used to get things rolling.
Software I Used:
Using the latest Afterburner 2.2.0 Beta 15, 12.4 Beta Catalyst, 12.3 CAP1
Best Way To Start:
Clean uninstall using AtiMan. Then Install of your choice of drivers and CAP profile.
Place the .dlls in the MSI Afterburner folder.
Note: You can also place them in their corresponding System32 & SysWow64 folders, but its not necessary. It works here.
Launch Afterburner, edited these settings, the new setting that worked for me was enabling Kernel mode, some users report this is not necessary, but for me to have Voltage control it was. Try it without, and if you still don't have access, try enabling low-level.
Edit Afterburner's shortcut and change the Target line: "C:\Program Files (x86)\MSI Afterburner\MSIAfterburner.exe" /XCL
Start Afterburner one time (it may pop up with a window asking you to reboot) and it will not start.
Go back in, delete the /XCL part of the target line.
Reboot machine now, and then re-launch Afterburner.
Conflicting Clock Settings / BSODs:
If you have enabled the Catalyst's own Overclocking menus, be careful changing anything as there have been reports of some users BSOD with Afterburner or other Utilities running. Even 2.2 Beta 15 does have a few glitches, its not 100% perfect.
BSOD While Idle:
CFX users may want to (probably have to) disable ULPS to prevent random BSOD while idling or starting games. Atypical stop codes of 37, 7E and even 116 have been seen without disabling Ultra-Low Power State / ZeroCore modes. Simply open up Registry using Regedit, and search for multiple instances of "enableulps" and switch it from 1 to 0. I am told the enableulps_NA doesn't matter but I just change them all to 0. There are about 8 cases of it in registry, not all of them are 1, but just get them all changed and don't forget to reboot for it to take affect.
Power Draw Limit:
You can change PDL in Afterburner, by clicking on Settings. Once in settings you can see on the main tab towards the bottom and see PDL is there. To make changes you must slide it to where you want, click Okay, and ONCE you are looking back at the main tuning of AB you will see that the Apply button has lit up. You must click APPLY to apply the changes of PDL you just made, they are not effective till you do.
We are getting a little bit of evidence showing that the memory clocks up to 350~400 MHz overclocks are achievable, some even higher, and they are equating to gains of 5% to 10% gains in performance (average FPS.) Now any higher I am sure it will either crash, or ECC will begin correcting so frequently that performance is lost. Find a sweet spot, that requires no extra voltage and if you can, keep an eye on memory temps. I noticed that the thermal padding that XFX used is relatively thick (>2mm) and may trap more heat in then transfers to the heat sink.
Pretty easy to overclock once the controls are back in our hands. Higher clocks = more performance. One small catch, a lot of users on air have noticed that as temps rise, stability declines. Temperatures we consider normal for a GPU (70~85c) range. Consider this when overclocking, stability may require additional cooling and what not. I am currently on water and I am 100% limited by the silicone, not temperature, so I have not personally witnessed this.
ASUS OC BIOS:
There is an ASUS OC BIOS, which unlocks the voltage to 1.400v. The only OC tool that can use it, I believe, is the ASUS GPU-TWEAK, the latest version at the moment is 2.0.83, and it is really buggy for me (CrossfireX) when it comes to synchronizing both Cards. Switching back and forth between both GPUs, causes me to lose my max voltage and forces me to be stuck at 1125v. It also doesn't apply overclocks to the second GPU unless I manually do it, causing me to lose the voltage. I recommend not using this at the moment if you are benching multiple cards.
You can get it here:
Asus.HD7970.3072.120104.zip 41k .zip file
ASUS GPU-z Tweak: http://rog.asus.com/forum/showthread.php?2624-GPU-Tweak-(Beta)
Make sure to get a backup of the original ROM before continuing! You can simply do this by grabbing the VBIOS with GPU-z. DON'T FORGET!
Make sure you are running as Admin when you try, if it fails try the command to force flash if vendor-id warning appears:
atiwinflash -f -p 0 ASUSOC.bin
Multicards should be:
atiwinflash -f -p 0 ASUSOC.bin
atiwinflash -f -p 1 ASUSOC.bin
atiwinflash -f -p 2 ASUSOC.bin etc.
WARNING: Flashing is risky, no one at OCN or myself, take responsibility for whatever you do to your cards. That applies to all the aforementioned overclocking as well.
It doesn't hurt to keep an eye on voltages from a few utilities, but the only way to be 100% sure what voltage you are seeing is with a voltmeter. Many users have reported spiking in voltage sensors, in Afterburner, GPU-z, and HWinfo32. HW Monitor and AIDA 64 also provide voltage readings to I believe. Use your best judgement in reading the sensors, and trust your gut. I usually play it safe, but I am also on water, so I have more wiggle room regarding voltage fluctuations. Being careful is the resounding message I am trying to push across.
One Final Thing:
Different Benchmarks and Games can and probably will have different Max overclocks. Don't be disappointed if your Max overclock crashes in BF3 but nothing else, be flexible with the overclocks. Don't forget, just because a game crashes, does not prove you or your overclocks are fully at fault. Could be nothing more than a game bug or more likely a driver issue. Keep chugging a way and have fun!