Heres is my system specs.
EVGA GTX580 OC2
i7 2600k @ stock speed
intel mobo
16gb's of microns lowest latency ddr3 ram
2 RAID'd terabyte SATA drives
Win 7 Ultimate 64-bit
using onboard audio,
latest available NVIDIA 285 beta drivers.
before and after the patch... the popin was horrendous. I fixed with some tweaks since there where no graphics options at the time (until the patch).
Now they were back again, and the texture cache seemed to have no effect on texture quality.
So I was back to horrendous textures and pop-in. all in game settings were maxed out, even AA was at 16x
until this...
try follwing these steps exactly as i have them:
I removed my profile for RAGE from previous tweak recommendations (I set triple buffer and vsync in nvidia control panel back to global setting instead of forced on)
I then did the following from the new RAGE settings menu:
(1) set desired resolution
(2) Turn antialiasing down to 4x
(3) set vsync to SMART
(4) set anistropic fileting to HIGH
(5) set texture cache to LARGE (if ur card can handle it)
(6) set GPU transcode to ENABLED if able to.
Make ABSOULTELY sure to disable any custom settings from config or launch options in steam, and nvidia control panel, if you had set any prior to attempt manual tweaking.
once i did, saved the settings, and restarted the game... my god.... the graphics were drop dead gorgeous, with absoultely, positively, not a single hint of texture corruption or popin. It didn't even look like 4x AA either, it seriously looke like i was still set to 16x. ran smooth as silk, and just looke dperfect, like a game should on a PC

as soon as I set the anti-aliasing back to 16x... textures were washed out, were not drawing in the distance, and had pop-in.
I honestly beleive everything now is driver related. This pretty much proves it for me.
See if this fixes it for you.