Where does Rage store its savegames

First of all check that you have installed the last drivers from your video card vendor. If you have an ATI, like me, these are the recommended preview drivers that improve performances for RAGE and Battlefield 3: AMD Catalyst™ 11.10 Version 2 Preview Driver

In addition I applied the Mid-End config suggest in this Steam's thread (all credits to FusedCore). There are other three config, choose one based on your system configuration, look at the comments and try to customize it a bit.

I have an ATI Radeon 6850 with 1GB and 3 core CPU, and now the popping issues are less evident. There is still some occasional 1/2s freezes or some stuttering but it helped me a lot.

Finally today (09 October 2011), it has been released the first support patch.

The new "Texture Cache" option in the video settings menu allows you to increase the texture cache size to keep more texture data in video memory.

If the Texture Cache is set to LARGE then RAGE will keep more texture data in video memory. This may not only significantly reduce blurry textures and texture popping, it will also allow complex scenes to be rendered with more texture detail.

Update 10/10: I tested the latest patch and texture popping seems not too bad with LARGE Texture Cache; it is instead dramatic with the other setting. To compensate they have introduced a really nice continuous micro-stuttering so now the game is unplayable for me.

Update 11/10: This "magical" setting for game launch parameters helped a lot in my case (ATI Video Card) both with texture and stuttering issues. Give it a try:

+jobs_numThreads 0

The quick answer is no, you will not lose your saved games. What you will lose is your current auto-save, as can be seen by the following screenshot:

You can see that while I am at the game's very beginning, which is where the current autosave is, I still have my saved games from a later stage.

When you choose "Continue Campaign" from the main menu, what the game does is load your auto-save. When I loaded one of my later saves and got to the point where the game auto-saved, continuing the campaign loaded that save, instead of putting me at the beginning (where I ended up until I did that).