how fast is a 040 cpu?

[Karlos]

Twice as fast seems like an underestimation to me. Most of the benchmarks I've ran in my time show that the 25MHz 040's I've owned have been 1.5 - 2x as fast as 030's running at 50MHz, i.e. 3-4x faster per clock.

This, of course, is on boards having their own Fast RAM. The stock 3640 board for the A4000 is crippled by the memory interface.

[Karlos]

hi will it say that the stock 040 is not so much faster than my 030 i have now?
remember i only have 18 mb ram.
what if i buy a 128 mb ram board and put in, with my 030 cpu will it increase speed

If you can get an 040 board with it's own local memory, the 030 won't see it for dust. Adding RAM to the system through the Z3 will just give you more memory to do stuff, you won't see any real speed increase.

An 040 board for the A4000 really only makes sense if it comes with sockets for attaching local RAM.