High Quality AA and AF
Our high quality tests let us separate the men from the boys and the ladies from the girls. If the cards weren't struggling before they will start to now.
Cranking up the detail, we don't see much movement; we've got everything from a little more to a little less seen here.
While in our games we're not seeing much, the consistency of the performance gains make us more confident that the extra FPS is coming from Service Pack 1. It seems to be more reflected in areas where the detail isn't as intensive. With that said, though, that theory does go a little out the window under Aliens vs. Predator which is one of, if not our most intensive game here.
Outside of the performance bump, though, we didn't run into any problems when it came to our system being stable and that's the most important aspect of an update like this. It's hopeless to get a few extra FPS here and there to then be greeted with a system that becomes unstable.
For the most part, though, we can't really see any reason why you wouldn't choose to install Service Pack 1. It doesn't seem plagued with issues like other Service Pack updates and combined with the large line-up of fixes in it, this is one you should probably upgrade to.