Although Borderlands 2 can be a bit demanding in certain scenarios, most gamers will be happy to know that playable frame rates can be achieved on a relatively affordable gaming setup. Unsurprisingly, Nvidia's graphics cards generally outperformed what would usually be considered AMD's equivalents.
For those gaming at 1680x1050 or similar resolutions, we found that very modest GPUs like the Radeon HD 6770 (aka the 5770) were able to deliver decent results, but again, Nvidia's performance advantage allowed budget GeForce cards such as the GTX 460 to produce 58fps, besting the HD 6850 and HD 7770.
At 1920x1200, the GTX 660 Ti could be considered overkill as the GTX 660 was only 1% slower while being 30% cheaper. That said, the GTX 660 Ti helps fill that gap by shipping with a free copy of Borderlands 2, so you'll have to determine what works out to be the best overall value in your situation.
Things look a little better for the GTX 660 Ti when playing at 2560x1600, as it held a 12fps lead over the GTX 660. Factor in the free game, and this seems like the best value going if you're looking to play Borderlands 2 at really high resolutions. Nonetheless, the GTX 660 still delivered a solid 52fps.
Although you may need an Nvidia card to max the game at 2560x1600 with more than 60fps, AMD's mid-range and high-end GPUs offered playable results at all three tested resolutions. Additionally, thanks to a mod, most Radeon owners will be able to enjoy Borderlands 2 in all its glory with PhysX enabled.
In fact, based on our testing, Radeon cards seem to handle PhysX slightly better than their GeForce counterparts. When running Borderlands 2 at 1920x1200, the HD 7970 only took a 15% performance hit after enabling PhysX (dropping from 72fps to 61fps), whereas the GTX 680 fell 19% from 74fps to 60fps.
We were a bit worried about AMD's GPUs going into this because Borderlands 2 is a "TWIMTBP" title, but it seems we should've placed our concerns on the company's CPUs. Dual-core chips like the Phenom II X2 couldn't provide playable results, the Phenom II X4 and X6 were on par with Intel's old Core i7-920, while the FX series was roughly 20fps behind newer Core i7 parts. Additionally, Borderlands 2 responded far better when overclocking the i7-3770K than the FX-8150.
It seems your CPU choice may be more crucial to Borderlands 2's performance than your GPU choice and you'll definitely want to play with a quad-core chip. For the best value combo, we recommend an Ivy Bridge Core i5 with the GTX 660 or GTX 660 Ti, depending on your resolution and preferred frame rate.