I just decided this past month to upgrade my computer that I built just about 1 year ago to one with two Gigabyte GV-R797OC-3GD in crossfire. My original card that is a year old is a hardware revision 1.0 while the new card is revision 2.1. These cards are not reference AMD design and have their own Gigabyte Windforce 3X "Triangle Cool" Technology instead of the reference blower. You can even see that Guru3D did a review of the revision 1.0 card just like mine back in February 2012 right here http://www.guru3d.com/articles_pages/gigabyte_radeon_hd_7970_oc_windforce_review,1.html My old GV-R797OC-3GD could overclock to 1200mhz core and 1650-1700mhz on the ram no problem with some extra voltage that I had changed through MSI Afterburner. I figured that with a year to have perfected the 7970 fabrication process and that they would easily overclock higher than older ones. I hadn't read up on the fact that the cards these days are almost all voltage control locked. I have the new rev 2.1 card in the primary slot with my 1.0 card in one of the lower slots. With this setup right now, its pretty unstable at almost anything above the stock factory overclock of 1,000mhz on the core with reference speeds on the ram at 1,375mhz. Would swapping their places make any difference in the overclockability of the cards? Is there any kind of bios that you can flash to the rev 2.1 card that would allow voltage control? Having 2 bios and a switch to select between them makes updating or editing the bios seem like such a mundane act these days compared to when you only had 1 bios chip and only one AGP slot on your motherboard for which to hook up a video card. MSI Afterburner mentions some stuff about extending official amd overclocking limits, disabling ULPS, entering unofficial overclocking modes with or without PowerPlay support (and also disabled?), and the ability to reset the display mode on applying unofficial overclocking. What does all that crap mean and what should they all be set to? Also what should I be using for my layout in the case? Should the rev 1.0 go back to where it was when it was my only card and the rev 2.1 be the secondary card? It would be incredibly easy for me to swap their places and I might do it just as a test. Using mini displayport plugs is far less annoying than unscrewing a DVI cable every time I wanted to move the computer around. Heres what the current setup looks like with the rev 2.1 on top vs the rev 1.0 on the bottom. You can clearly see a lot of hardware differences with one of the most obvious being an extra metal heatspreader on the back of the card over some of the voltage regulation chips. There's also just a lot more little components on the surface of the PCB from what I can see. Maybe they were on the top side in the earlier models and moved to the other side now but who knows. The cards run awesome together pumping out amazing looking scenes in 2560x1440 with everything in games turned to max as well as 16x af and a little bit of various types of FSAA to go with it. Every once in a while I can notice some slowdowns but they are so minor that I don't think most people would notice that much but if I could overclock them both I know it would just be that little bit better that could make all the difference. The single 7970 was sufficient for running games at 1920x1200 most of the time but when I upgraded from my Dell 2405FPW (now my secondary monitor having replaced the 2001FP that used to fill that role) to a Dell U2711 that has a native resolution of 2560x1440 you could tell that it was struggling with all those extra pixels and even needed settings turned down a bit in a bunch of games to get an acceptable frame rate. Not so now with the 7970 crossfire setup now though. So basically can anyone help me get this extra speed out of my rev 2.1 GV-R797OC-3GD so that it can run along well with my rev 1.0?