Mac Pro & VI's- Best-case latency? System configuration?

[Allan Speers]

I'm trying once again to somehow turn my PT TDM rig into a workable composition tool.

Same old problems: Inability to run more than a few VI's at once (if that) and LATENCY ISSUES.

I am currently using a dual-2.7 G5 PPC.

Benchmarks:

When using Ivory, and no other VI's loaded, I can set my HWW buffer for 128 while recording the midi and/or playing back via midi.

When recording this Ivory midi to an audio track, I must change the buffer to 256, or do a lot of punching-in to fix clicks & stutters.

With Kontakt II, I must use a 256 buffer always.

The thought of having one instance of Ivory, one stereo string track, and some drums, all playing as virtual instruments is an unobtainable goal, unless I use a 512 buffer. (which is of course out of the question.)
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I'm considering getting the latest Mac Pro, but this would be a huge expense, since I'd also need new Digi cards & a new expansion chassis.

I'm hoping those of you with the current Mac Pro, who also use VI's a lot, can give me some of your benchmark numbers. Items of interest:
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1: With ONE VI instantiated, (preferably Ivory, so we have a standard reference) how low can you set your HW buffer for recording / playback of midi, and for rendering to audio?

2: How many stereo VI's can you typically run at once (as virtual instruments) ? Again, preferrably Ivory and Kontakt II, but definitely stick to VI's that stream samples. If using others, then of course list what they are.

3: What other PT playback-settings you use?

4: What type of drive subsystem do you use for your sample libraries? (speed, interface type, one large drive or separate drives for each VI, posibly raid, etc )

5: How much total ram you have installed? (PT can, of course, only use 4 gig total at this time, but system overhead might matter)

6: How many procs can you use?

7: any other thoughts or info concerning performance and/or optimization.

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It would be great to see this become an ongoing thread. We need such benchmarks desperately.

[Ray Lyon]

Allan,

I use a G5 dual 2.0 w/ the same VI's you mention and do not have a latency problem as you describe. Your machine should have more than enough horsepower to do what you're asking of it...

A few troubleshoot questions...

1> Are Ivory samples on a separate 7200RPM internal (or Ext. FW800) drive?
2> How much RAM do you have... 4+ gigs is good... I had clicks at 2.5GB
3> Are there any latency heavy plugs on the master fader? (remove if there are)
4> How high is polyphony set on Ivory? Make it as low as possible.
5> Are you using latest version of PT, which is approved with your operating system?
6> NI plugs like Kompakt are often problematic in PT RTAS... code is not optimized for PT... I'd avoid them

With 4.5GB RAM I use Ivory, Trilogy, (2) Atmosphere, (3 or more) Xpand, Strike plus more with no problems...

HTH

[Allan Speers]

Thanks, Ray. This is a good start, and good news.

-But What drives for your VI samples?
-Both Procs enabled?

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I have been using three external FW800 drives for my VI libraries. (PT audio on a scsi 320 subsystem) Ivory on one, Kontakt on another, and everything else on a third. I've actually been considering eSATA or even a raid system (if PT will allow it) but I have a feeling my drive system is not part of my problem.

Ram was definitely part of my problem. Unfortunately, when I first got this G5, the Mac OS limited any one application to only TWO gig. Now it's four, but I wasn't aware of the change, so I've been limping along for 3 years on 2.5 gig total. I just ordered another 4 gig, so hopefully that will make a huge difference.

[Ray Lyon]

Thanks, Ray.

-But What drives for your VI samples?
-Both Procs enabled?

I have been using three external FW800 drives for my VI libraries. (PT audio on a scsi 320 subsystem) Ivory on one, Kontakt on another, and everything else on a third. I've actually been considering eSATA or even a raid system (if PT will allow it) but I have a feeling my drive system is not part of my problem.

Ram was definitely part of my problem. Unfortunately, when I first got this G5, the Mac OS limited any one application to only TWO gig. Now it's four, but I wasn't aware of the change, so I've been limping along for 3 years on 2.5 gig total. I just ordered another 4 gig, so hopefully that will make a huge difference.

I'm not 100% sure, but do not believe PT allows use of RAID system...

My FW800 drives are 120GB each, total of 4 drives daisy chained in (2) Storecase 1 space hot swap enclosures... I have Ivory on drive #3, all other sample libraries are on the internal drive...

1 processor enabled at the highest % (can't remember the number)

Additional RAM should help immensely... it will be interesting to see if you still will have problems with Kontakt... again, I avoid the use of NI plugs in Pro Tools whenever possible... when you get your RAM, test Ivory alone and then instantiate Kontakt and see what happens...

BTW, what version of PT and Mac OS are you using? And make sure the delay comp is off.

[Allan Speers]

Interesting. I seem to be the only user that can use both processors without pops & clicks. Makes me think that only a few VI's cause this problem. My new ram just arrived, so I should have something to report later this evening. (and tested as you outlined)

Ray, if I read your last post correctly, you are using FW800 for both your Ivory samples AND your session audio, on separate drives but on the same bus. Yes? -So then that tells me just how little a demand VI's put on the drive throughput.

Since I use scsi for my audio, I guess I no longer need to consider a raid system for my VI libraries. (even if PT allows it, which oddly no one seems to know, not even Digi techs)

FWIW, I use the current beta version of PT (I'm a beta tester) but I can't talk about specifics. Bottom line is just that my PT version is not affecting anything germain to this discussion. Had I been using PT 7.x or earlier, then yes there would be some specific issues with Kontakt II and a few other VI's. Good thinking, though.

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Still hoping to get some feedback / benchmarks fro Mac Pro users. Anyone out there?

[Ray Lyon]

Allan, I really haven't gotten into detail with the dual processor usage w. RTAS since I had been reading by many posts incl Digi tech support to stick with one processor for now... maybe that will change w/ PT update...

Yes, my Ivory samples and audio are on the same bus... I do not do heavy edit density tracks... so perhaps this gives me better throughput than some...

Have fun with that beta version!

Ray

[drenkrom]

I never cease to be amazed how a native DAW with no DSP to handle the playback engine and delay compensation can absolutely wipe the floor with Pro Tools when it comes to using virtual instruments and native plugins. It would really be time to ditch RTAS or at least integrate a more efficient protocol, especially if you're going to try to sell native systems to people who will obviously compose with their systems, as with M-Powered. I wouldn't run a recording session on anything but Pro Tools, but for composition it is way sub-par. You should not need 4 gigs of RAM to run a few VI's and my experience has demonstrated you never do, except in PT.

This doesn't help resolve the problem at hand, but maybe with enough hints, Digi will move in the right direction. *hint* *hint*

[Allan Speers]

drenkrom,

would you tell us a bit about your system, hardware , software settings, and what type of VI performance you get?

I am really hoping to get a useful list of benchmarks here.

[Allan Speers]

Bump.

Are there really no VI users out there with Mac Pros?

No one can tell me what the best-case, lowest HW buffer will be?

[soundonsound]

I use Mac Pro and V.I.'s all the time.

I can run 128 with Strike, Structure and 4-5 Xpands open no problem. Which I find pretty amazing. I have 4 10,000rpm 74gb raptors inside all SATA.

Pro Tools does not support Raid, 100% fact. Stated on their internal drive requirements page which sounds like you should glance at:
http://www.digidesign.com/index.cfm?...4&itemid=23142

and no raid on external drive requirements:
http://www.digidesign.com/index.cfm?...4&itemid=23114

Raid can decrease overall performance and cause system instabilities on any machine when using PT. Avoid at all cost.

Soundonsound.com has stated the Raid is mostly benificial for Video files and small files (such as under the PT 2GB file limit) actually receive great performance on single un-raided 7200rpm+ drives and the average DAW doesn't have much use for RAID from a performance standpoint. Data security would be another issue.

Something doesn't sound right with the setup. I don't use Ivory so I can't say how much of a hog that should be. Most all N.I. plug-ins are pretty unstable in the PT world. Those might not be the best V.I.'s to tax PT with. I know Xpand, when you load multiple copies of it, they know how to allocate resources in such a way that they share some of the same processing. If you open one, then another, you'll notice they don't open the same amount of cpu power the second, third, etc time around..

How's the new Ram working out?