device pcm kills SMP performance -CURRENT

[matthew tillman]

Hello-
I have an ACorp 6A815EPD motherboard, Intel i815
chipset, with a pair of P3 733s.  My sound 
card, is a SoundBlaster Live Value.
 
Whenever sound support is compiled in the Kernel,
performance takes a 
huge hit, X runs about the same as on a P2 300 or so. 
But If I boot to 
a kernel that is configured exactly the same, without
device pcm, the system is very 
responsive.
 
Booting to a non-SMP kernel in 5.1-Release with or
without sound support, the system was very fast.  I
did not try no sound support with SMP, as I thought
the issue was only SMP performance in general.

I then CVSuped to -CURRENT on Nov 8th, because at the
time I didn't realise the issue was isolated to the
sound system.  However, I still have the same issue.
 
I also tried swapping the card into a diffrent PCI
slot, but that 
didn't help.
 
Any ideas?
Thanks,
Matthew