Ok... I got this running decently on my GeForce GTX 260!! Had to add a new rule to the Graphics Rules.sgr file. I think the newer GF8, GF9 and GF GTX200 series have the problem like the older Radeon cards with very slow Partial Depth Buffer copies. I used the rule that was setup for the Radeon cards and got it working for GEForce 8,9 & GTX 200 series cards. I've only tested this on the GTX260, but it makes scrolling smooth again. Only downside is all the shadows disapear while scrolling, but they redraw again when you stop moving. Open the Graphics Rules.sgr file, in your SimCity 4 folder. Scroll down to the near the bottom of the file and add this. I added it between the "NoAddSigned" and "Not Slow GeForce" rules.
partialRule "GEForce 8/9/GTX200 Slow-Down Fix" stringMatch cardIdentity "*GeForce*" partialRule "SlowSubrectDepthCopy" -any stringMatch cardIdentity "*GeForce*8???*" stringMatch cardIdentity "*GeForce*9???*" stringMatch cardIdentity "*GeForce*GTX*2??*" # results in special low-impact scrolling mode. property noPartialBackingStoreCopies true end end
