digital performer works better with the internal audio card

[moscow studio]

hi guys, I run DP 5.13 on OSX 10.5.4 and I've noticed that it really works better when I'm using the internal audio card (I'm on an alu imac)
I was finishing a mix and I'got a bounch of plug ins going. not too much. audio buffer was 1024.
I started listen to severel hiccup in the audio playback, is quite normal for me the have them. after a while I've decided to listen the mix in the imac speaker, just to check it on small speakers. so I've changed the audio card.
after that everything worked better: no delay in editing, no hiccup, no nothing!

I'm started thinking that my audio card (presonus firestudio) could be the cause of degraded performances and crashes (I got lot of them when editing, copying, fading...lots of them)

is it possible? how can I check it?

[Frodo]

I'm not sure what the speed of your aluminum iMac's firewire port is, but most Macs have 33mhz busses. The 2008 towers now have firewire that are running about 2500mhz (thereabouts), which is closer to PCIx performance. The larger number means better performance. I'm not really surprised that the Built-In Audio works better at times (or more predictably). That has been my experience, anyway.

There are other things that could be looked at with no guarantees that they'd help, but they *have* helped at times. In addition to try the buffers at 1024, you might want to set DP's work priority to HIGH, unless you're running anything in standalone mode. If you using everything inside DP, then setting DP's WP to HIGH gives it a little CPU muscle.

DIsable "pre-fill buffers" in The Setup Menu-- under Configure Studio Settings.

But again-- that Built-In is working better means that the problem most likely rests elsewhere. It could be with how the firestudio driver is interfacing with Core Audio. It could be how both of those are interface with MAS. When you use Built-In, there is one less framework in the way where MAS and Core Audio work in a pair with Built-In Audio. Add a third party audio interface and Core Audio and MAS must shake hands with extra audio driver. The amount of data being ported at once could be the magic bullet that makes OSX, DP, and the CPU work harder to process all the data.

If the firestudio otherwise works fine routing iTunes or iMovie audio to your speakers, then it goes back to either firewire performance, the integrity of the presonus driver, or even some quirk in the firestudio itself. Have you tried a fresh FW cable? Sounds simple, but sometimes it's that simple.

I've seen this happen before, and I use Built-In for a lot of testing and troubleshooting because it tends to work quite reliably, even if it isn't quite as flexible as a dedicated interface.

[moscow studio]

thanks Frodo, it is interesting to see that I'm not the only user that have noticed that.

I will surely try to disable "pre-fill buffers" in The Setup Menu, usually I keep them on but now that you've pointed my attention to that I am thinking that this option could be releated to the delay that sometimes happen when I hit play. work priority is high yet.

firestudio in general works well with itune or quicktime, and also work well with DP before going to mix. when the CPU is stressed, it seems that the firestudio stresses it a bit more. DP become slower (editing,cutting, moving, etc...) and I get crashes and hiccup.

do you think that a MOTU interface performs better under this point of view? thinking about the new 828mk3. I've thought to change the firestudio several times but I would like to know if I can get a better stability

[kassonica]

There have been some issues with the firestations and presonus drivers and FW chips in general

This may account for your problems.

[moscow studio]

what about the 828 mk3 and DP?
It really works well as expected, being both from MOTU?

[1nput0utput]

I recall Presonus drivers being a little squirrelly under OS X. Try setting the work priority setting in DP to medium or low. I think that should make DP happier with Presonus FireWire interfaces.

[Pokeye]

what about the 828 mk3 and DP?
It really works well as expected, being both from MOTU?

828 mk3 works great with DP5.13. I also think it sounds better than my old pci424 and 2408mk2 as well...