Apologies for being slow on the uptake with this news; I was out of the office on family business late last week. The fallout from the kinda-exploding GeForce GTX 590 cards continues, with both Nvidia and Asus taking additional steps to prevent the catastrophic release of the magic smoke sealed inside each and every card.
The main cause of the problem, as we've noted, appeared to be excessive overvolting during overclocking attempts and the failure of the card's onboard power-protection circuitry to prevent the worst. We first understood this problem to be confined to an early driver set which shipped out to reviewers—and potentially to end-users, I believe—on a CD enclosed with the card. We used slightly later drivers in our testing, prior to the GTX 590's release, and the card correctly slowed down clock speeds during our too-aggressive overclocking and overvolting attempts, saving us from fiery grief.
We now understand part of the potent cocktail of smoky death may have also been a modified video BIOS shipped on Asus cards that allowed more extreme overvolting than the 1.025V peak we attempted. (Since our review unit was a reference model directly from Nvidia, we weren't able to venture much beyond that point.)
Now, Nvidia and Asus have made further adjustments in order to prevent problems.
The biggest news on this front, in our view, is that Nvidia has put the clamps on GTX 590 voltage in its drivers. We shot down a rumor last week that the public-release 267.91 drivers somehow reduced the performance of a stock-clocked GTX 590. They simply do not. However, we've since learned Nvidia has capped the voltage at the default 938 mV on GTX 590 cards starting in release 267.91. We've confirmed that the latest 270.51 betas will not allow us to raise our GTX 590's voltage at all using MSI's Afterburner utility.
This driver-based cap means that even fairly modest overclocking may no longer be feasible with the GTX 590. Our so-called WICKED config only took the GPU core to 690MHz, and getting there required a bump to 963 mV. With Nvidia's latest drivers, a modest overclocked config like WICKED is not viable. The clock speed slider is willing, but the voltage is weak. GTX 590 owners will have to settle for whatever minor frequency increases they can achieve at stock voltages.
Given the way our GTX 590 card tolerated a reasonable bump up in voltage, we think this zero-tolerance voltage cap is probably a PR-driven overreaction. Then again, our WICKED config admittedly drew quite a bit of power—enough to make us uncomfortable. Either way, unfortunately, this change means GTX 590 owners will be robbed of what little headroom their cards may have in store.
We'll call it the Way-Extreme Amperage Kap, or WEAK.
Meanwhile, Asus has released a new video BIOS for its GTX 590 cards that apparently limits its VoltageTweak overvolting feature to more manageable levels. Some folks have taken the release of this BIOS as confirmation that all GTX 590 cards have a problem, but Nvidia tells us it has not issued an official BIOS update for the GTX 590. Fuzdilla got an official statement saying the same. Asus appears to be the sole source of this updated video BIOS.
Incidentally, one of the juicier rumors we've heard in this whole affair is about that Sweclockers video of a GTX 590 going poof. Some of you have wondered how the site happened to be filming that GTX 590 exactly at the point of its death. We wondered the same, until a well-placed source hinted that the card in the video was not the first to die at the hands of that particular reviewer. We hear Sweclockers may have sacrificed its second review unit, a replacement card, in order to obtain that dramatic video footage, recreating the conditions of the first card's failure with the camera rolling.
If true, wow.
One more bit of info for you. We've run the GTX 590 (at stock clocks) through the bulk of our GPU test suite using the new 270.51 beta drivers to see whether there are any notable performance gains, and the answer is no. Nvidia has cited some frame rate gains in specific games at specific settings for several cards, including the GeForce GTX 560 and 580 in single-card and SLI configurations, but none of those scenarios overlap directly with the games and settings used in our test suite. Outside of those scenarios, pretty much nothing has changed, as far as we can tell. You'll still want to update your drivers in order to take advantage of the Dragon Age 2 optimizations, but don't expect too much beyond that.