If the new Firestorm with PBR runs super slow on your system under Windows, run the Linux version under BookwormPup64. It's much faster and smoother. I gained at least 20 FPS more speed; even with higher graphics settings*.
BWP64 is the only Puppy that it will run under. No Fossapup, no EasyOS (DARN DARN DARN!), no nothing; just Bookwormpup64. My only two uses for Linux are getting the new FS to run and surfing questionable websites, so BWP64 is great for that. Oh yeah, the older FS (non-PBR) just zoooms at 60-80FPS. It's amazing.
*WIndows: 5-10 FPS on low. No way on Ultra with mirrors.
BWP64: 25-30 FPS On Mid/High. About 3-5 FPS on Ultra with mirrors but it does run. At least I can look around a bit.