Well, a 280x is ~670, so why did you just hop sides? No substantial performance boost would be gotten from getting the equivalent GPU from a different company.
If increasing the IR causes an issue, then you might be running into an NB, GPU, or VRAM bottleneck. The lattermost is, by far, the most likely, since, iirc, the HD 7800 series cards (270, 270x now) had higher effective memory bandwidth than the 7900 cards (280, 280x now), and the 7800 GPUs were definitely not the best on the block for memory speed.
Though, I don't see how it could be happening at such a low IR. Maybe... well, looking at the settings you have in your sig, did you turn off LLE on thread, and turn off force texture filtering? And, with your hacks, try turning off Skip EFB Access.
If increasing the IR causes an issue, then you might be running into an NB, GPU, or VRAM bottleneck. The lattermost is, by far, the most likely, since, iirc, the HD 7800 series cards (270, 270x now) had higher effective memory bandwidth than the 7900 cards (280, 280x now), and the 7800 GPUs were definitely not the best on the block for memory speed.
Though, I don't see how it could be happening at such a low IR. Maybe... well, looking at the settings you have in your sig, did you turn off LLE on thread, and turn off force texture filtering? And, with your hacks, try turning off Skip EFB Access.
in a perfect world we would all be piles of sand with no ability to form coherent bodies of body