Performance of Heap table?!

[chchen]

Hi all

I find out that the performance of Heap table seems bad than MyIsam table.
of course, MyIsam table usually on the H.D., so it will slow down
because of I/O.

but i do a test. I mount a memory disk on FreeBSD 
and update/inser a table. I find out that would faster
than use Heap table with the same structure.

and the speed almost double while the table grows up
to 200K+ rows

any ldeas?

Regards 
chChen