IDE/DMA/VIA chipset question (compiling new kernel)

[Jeronimo Pellegrini <jeronimo@iname.com>]

Hello,

  Before anything else, I'd like to thank the people who have helped
  me before. This has been really nice... And so far, support here in
  this list has been really efficient. Thank you all.

  Ok - now, to my little problem:

  I have a Pentium II 400Mh with 64Mb RAM;  my motherboard and HD both
  support DMA/66, the CD-rom drive also supports DMA/33.

  I'm running potato now, and I've compiled a new kernel
  (2.3.47), optimized for my box... But at a certain point when
  running make xconfig I had one doubt... 

  According to the help box, I shouldn't choose to "use DMA by default
  when available" is I have a VIA VP2 chipset. Well, I have a VIA
  693/596 chipset in my motherboard (which has 2 PCI IDE interfaces
  on-board)... And I don't know if my chipset would be somehow
  "related" or "derived" from the VP2, or whatever... In short, I
  don't know if it's safe to use DMA by default... So I've compiled it
  without it.

  Now... My questions are:

1) How much difference would that option  make?

2) Would it be safe to compile the kernel with that option?

Thanks a lot!
J.

-- 
Jeronimo Pellegrini
Institute of Computing - Unicamp - Brazil
http://www.dcc.unicamp.br/~jeronimo
mailto:jeronimo@dcc.unicamp.br    mailto:pellegrini@iname.com