FSR 4 INT8 provides better image quality than FSR 3, but is slower. For example, in Performance mode, the performance increase in 4K was about 28%, while FSR 3 gave 29%.
But there are also advantages. In Alan Wake 2 tests at 1440p, the new version provided 4% more frames and a sharper image compared to FSR 2 in Balance mode. This suggests that on the Xbox Series X, which supports INT8, the technology may perform at its best.
There is one limitation: PS5 does not support the INT8 format, so many multiplatform projects will not use FSR 4 INT8. AMD continues to work on the technology, so the final results may change.
So far, FSR 4 INT8 has performance limitations, but it can improve image clarity in some games on Xbox Series X.