I wrote the following program to initialize RAM in the "user basic area", just for the fun of it. It runs really fast, like almost instantly. I know VICE tries to simulate speed of processor cycles. I don't have a real VIC up and running well enough yet to try this. Is the 6502 really that fast or is VICE not as accurate on something like this?
These three lines are executed most of the time and need 6 (STA(),Y) + 2 (INY) + 3 (executed BNE) = 11 cycles per iteration, for 256 iterations (except for a few missing bytes in the first page) per page, and 14 pages in total.
11x256x14 ~= 40000 cycles.
On a 6502 running at 1 MHz, that takes 40 milliseconds.