firewire soundcard makes my iMac lag

[bontempi]

hello

when i plug my firewire soundcard (Echo Audiofire 8) to my new 24" iMac 2.66 ghz + 4 gigs RAM + 9400M , the graphics aren't fluid anymore.

Dashboard lags, expose lags ... it doesn't "slow down", there's just a clear drop of frame per second, that makes me feel i'm back to a GMA950.

there's nothing in the activity monitor that takes too much CPU.
i restarted the mac : same thing.

fresh OS 10.5.7 ... don't get it. any idea ?

thanks

 

[Hellhammer]

Drivers maybe? Some 3rd party hardware aren't OS X best friends

 

[bontempi]

i plugged an external hard drive instead of the soundcard (which needs no drivers)

when i copy files : the lag appears
when the disk is iddle : no lag

...

looks like either the iMac or the OS has a problem

 

[Hellhammer]

Your FireWire port can be defective. I would give Apple a call.

 

[bontempi]

spent half an hour with apple.
we haven't found anything. he told me to return the iMac if i wasn't happy as it's brand new

then i've found this thread
http://discussions.apple.com/message.jspa?messageID=9248655

looks like a driver problem ... hope it will get fixed with 10.5.8

i will do some tests in windows with bootcamp

 

[Hellhammer]

spent half an hour with apple.
we haven't found anything. he told me to return the iMac if i wasn't happy as it's brand new

then i've found this thread
http://discussions.apple.com/message.jspa?messageID=9248655

looks like a driver problem ... hope it will get fixed with 10.5.8

i will do some tests in windows with bootcamp

Okay, good. nVidia drivers sucks because Apple writes them.

 

[bontempi]

how is that ?
is there any documentation on the matter ?

thanks !

 

[Hellhammer]

how is that ?
is there any documentation on the matter ?

thanks !

I don't know why Apple writes them. Maybe nVidia has enough work already. That's what I've heard and people usually recommends ATI for better drivers.