Microprocessor Speeds

[Perx]

I know this may sound like a ridiculous question, but I'm fairly new to the computer scene (I just decided to join the 1990's).

What is the difference between a 68030 and a 68040? I recently purchased a Performa 450 33MHz '030. Is a 25 MHz '040 faster than a 33 MHz '030? How do the speeds of the specific chips relate to each other? Would a Quadra 605 w/ a 25 MHz '040 be faster than my performa? If so, why?

I'm clueless on this point. Thanks for any help.

-Perx

[Perx]

[Perx]

Sorry about the hardware post. I forgot what group I was in. Won't happen again.

Cheers!!

--Steve

[Kelly Davies]

The clock speed (measured as megahertz or MHz) relates to how fast one cycle
in a processor takes. The higher the clock speed, the less time for one
processor cycle. Each processor instruction takes one or more clock cycles.
Therefore, the higher the clock speed, the less time for each processor
cycle, and the less time for a processor instruction to execute. Clcok speed
is a measure of raw processor speed.

However, on different processors instructions can differ in how many
processor cycles required to execute an instruction. The 68040 chip has a
more efficient design than the 68030. Instructions on the 68040 typically
take fewer clock cycles to complete; at worst, a 68040 can execute an
instruction in as many cycles as the 68030. A 25 MHz 68040 is faster than a
33 MHz 68030 because the difference in efficeincy is more than the difference
in clock speed.

The moral of the story is not to use clock speeds as a reliable measure
except when comparing similar processors. For example, just because a Pentium
can run at 100 Mhz doesn't mean it necessarily outperforms an 80 MHz PowerPC
601. The 100 MHz Pentium can outperform an 80 MHz Pentium, however.