If you flip the switch from position 2 where it ships to position 1 and reboot, your card is instantly overclocked. What was an 830MHz, 375W card running at 1.12v is now an 880MHz, 450W card running at 1.175v. Instant speed, just add BIOS and a few electrons. Isn’t that great?
Short story, no it isn’t, not at all. This is where 6990 goes from being the fastest, bestest, happiest-est card on earth to something you shouldn’t buy. No really, you should not buy one of these cards, go get two 6950s or 6970s instead, The 6990 has a fatal flaw, and it is simply due to an AMD decision, not hardware or software. If you flip that switch, you void your warranty. No really, you do. When I said that it wasn’t the case, I was flat out wrong.
Talking to some AIBs before an official briefing, several told SemiAccurate that there was no way that rumor was true, the card is designed to run at 450W, and that there is no problem doing so. At the time, they said that they would abide by any warranty, even if AMD didn’t. The next day, I was officially briefed on the 6990, and the handcuffs went on.
Sadly, during that meeting, I was told that AMD would indeed void the warranty if the card was used as designed, promoted, and expected. Unfortunately, I could not say so until the embargo lifted. Checks with multiple AMDers, and the presentation itself stated as much.
To say that this is stupid is stating the obvious. No, let me take that back, it is flat out irresponsible for AMD to do this. They designed the card for 450W, all the parts are spec’d for 450W, and they promote it as a 450W card in their literature, going so far as to make a marketing acronym, AUSUM, for it. But if you use it, your warranty goes poof.