General discussion about Rail Simulator that doesn't really fit in to any specific category. A good place to start if you're not sure what category it should fit in to as well.
Name: Intel(R) ICH9 Family USB Universal Host Controller - 2939
Device ID: PCI\VEN_8086&DEV_2939&SUBSYS_82771043&REV_02\3&11583659&0&D2
Driver: n/a
Name: Intel(R) ICH9 Family USB Universal Host Controller - 2938
Device ID: PCI\VEN_8086&DEV_2938&SUBSYS_82771043&REV_02\3&11583659&0&D1
Driver: n/a
Name: Intel(R) ICH9 Family USB Universal Host Controller - 2937
Device ID: PCI\VEN_8086&DEV_2937&SUBSYS_82771043&REV_02\3&11583659&0&D0
Driver: n/a
Name: Intel(R) ICH9 Family USB Universal Host Controller - 2936
Device ID: PCI\VEN_8086&DEV_2936&SUBSYS_82771043&REV_02\3&11583659&0&EA
Driver: n/a
Name: Intel(R) ICH9 Family USB Universal Host Controller - 2935
Device ID: PCI\VEN_8086&DEV_2935&SUBSYS_82771043&REV_02\3&11583659&0&E9
Driver: n/a
Name: Intel(R) ICH9 Family USB Universal Host Controller - 2934
Device ID: PCI\VEN_8086&DEV_2934&SUBSYS_82771043&REV_02\3&11583659&0&E8
Driver: n/a
Name: SM Bus Controller
Device ID: PCI\VEN_8086&DEV_2930&SUBSYS_82771043&REV_02\3&11583659&0&FB
Driver: n/a
Name: Intel(R) ICH9 Family 2 port Serial ATA Storage Controller 2 - 2926
Device ID: PCI\VEN_8086&DEV_2926&SUBSYS_82771043&REV_02\3&11583659&0&FD
Driver: n/a
Name: Intel(R) ICH9R/DO/DH 4 port Serial ATA Storage Controller 1 - 2920
Device ID: PCI\VEN_8086&DEV_2920&SUBSYS_82771043&REV_02\3&11583659&0&FA
Driver: n/a
I think it's probably impossible to completely eradicate stutter (just look at the jerky starships on Star Trek films to see what thousands of dollars of equipment can't achieve) but it can be reduced to an acceptable level.
I find it's a question of balance. Try to set you graphics card to run as fast as it can, within your system, and have your CPU running at around 3+GHz. Your memory also needs to be able to feed the graphics so consider 800MHz as a bare minimum.
You've got an Asus motherboard and they are usually very overclocker-friendly. Experiment and have fun.
Overmarze -- How does RailSim run on Vista, compared with XP? I'm wondering about Ultimate, myself.