nctechno,
Your post pozses several questions and to me is ambigous. If after reading this post you have a "specific question/problem" please post back.
One answer to one part of your question is no: The processes on a 64bit CPU system run at 64bit speeds. Much of the normal processing is waiting for I/O(these are short waits based upon system clock cycles and XEONS are in the MIPS range).
Another answer would be yes: if you are looking at total system speed/response and you have some application that is continually waiting for data from a particularily slow device say like a 14.4k modem. This is not the norm but illustrates/exagerates what waiting can do to performance.
SBC to me is a "Single Board Computer" what are you refering to?
32bit cards only refers to the data chunk size capability and not directly to data rate. Chunk size is only one component in determining Data rate.
Additionally, at this time most/many applications are still of the 32bit variety and therefore do not see direct benefit from a 64bit CPU.
rvnguy
"I know everything..I just can't remember it all