Yeah right, Thanks bethesda for this HD Texture pack! I PRefer play with the graphics of morrowind than with the lag you provide along with the HD pack!!

I Have GTX560Ti, Intel i5 2500 3.2Ghz (its quad core)
8GB DDR3 Ram

AND IT STILL L A G S ! ! ! ! ! ! ! !

Disable it then. I don't understand why people say it's lagging with such specs.

Is it slow if you only have the HD texture pack enabled or all the time?

As long you don`t post how much VRAM your Video Card has you don`t need to post info on the used Card at all.
It seems that more than 1GB VRAM is needed to get Skyrim run properly with the High Res Textures.
No problem here, watch my signature for more.

smooth as silk for me on a 560ti. I have other texture mods as well.

Silky smooth for me on my HD5870 1GB.
So, yeah! Thanks Bethesda for this HD Texture pack!

Or what AA settings they're running.

1GB with Vanilla low-res + 8xMSAA is np for most video cards with 1GB
1GB with High-res + 8xMSAA far exceeds 1GB and is too much for most video cards.

Solution: if you want to use high-res texture pack and maintain smooth gameplay, either reduce AA or buy a video card with more VRAM. Otherwise, just disable it.

Solution: Hi-Res DLC Optimized (TESNexus it)