[SWLUG] ide=nodma question

[asura at theexcession.co.uk]

i'm suffering from the following affliction:
http://kerneltrap.org/node/4993
http://lkml.org/lkml/2006/7/13/37
further googling seems to hover between an actual faulty (atypical) 
motherboard versus badly designed motherboard, right now however the 
only apparent workaround is the ide=nodma kernel option, with an amd x2 
3800 how much slower will this make my disk access, are there only 
certain types of apps where i would notice a slowdown?
i'm anticpating having difficulty rma'ing the mobo using quotes from 
linux kernel hackers as evidence!

bascule