So today I did the resistor swap that boosts the Performa 476 (LC 475, Quadra 605, etc) from 25Mhz to 33Mhz. And for fun I also swapped the 040 chip out with a couple others I have to see the difference. I tried with the stock 040 25 LC. an 040 33 LC, and a full 040 40. Using Mac Bench prior to the update as a baseline, the CPU performance benches at a 125% increase for all 3 CPUs. No surprise there. The FPU performance did not change at all between the original configuration or after the resistor mod, no matter the chip. Amusingly the FPU for the full 040 is 1400% faster than the 2 LC chips. Obviously the lack of an FPU hinders them, but I was not expecting such a big difference. The only item of concern I had, is that the 2 LC chips run at around 100°F/38°C while the full 040 runs at 120-130°F/50-55°C. Even though it is rated at 40Mhz and I am only running it at 33. I haven't run a machine with a full 040 since the 90's, and not sure I ever worried about CPU temp. Is that a standard temp for a 040 chip? Or is that too high. I've got some heat sinks on order so I may pop one of those on there and see how it goes. I'm just having fun maxing this little guy out with a 128Mb ram Simm and a Blue SCSI. OS 7.6.1 is pretty snappy, although that boot time with all that ram to check is no fun, almost a full minute. I see there is a spot for a ROM SIMM slot to be added. Anyone ever tried to stick a rominator in one of these? LOL starting to sound like an ActionRetro video.