Can't get above 50% on G5 w/Logic!!!

[HockeyMike]

I'm starting to mix songs that I've tracked since I picked up a UAD, and I'm getting pretty lousy performance compared to the other G5-ers that have posted on the forum.

If the UAD meter is below 40%, no problems. If it's hovering in the 50's, I'll get gaps in playback happening, maybe 2 or 3 times in a 4 minute song. The gaps are a little over 2000 samples in length when I look at a bounced file in the sample editor, so I'm guessing that has to correlate somehow to a problem with the card communicating with the computer since the I/O buffer is set to 1024 (the gaps being double that). If I push the UAD more, past 70%, I get major stuttering and a CoreAudio: System Overload error.

I've tried using internal audio instead of my Q10, but there's no difference.

Here's my setup:
G5 dual 1.8 (1st version with PCI-X)
OSX.3.5
Logic Pro 6.4.3
3.5 gigs RAM
2 SATA drives
Aardvark Q10
1 UAD-1 card
(UAD and Q10 PCI cards on separate PCI busses)
MIN_GNT at 64, AMD-8131 checked
Logic I/O buffer at 1024 (does the Process Buffer Range setting in Logic make any difference?)


Help! I should be able to get more than 40% reliably on a G5, even with their notorious \"issues\" with UAD's, right?

Thanks everybody,
Michael

 

[harvestmark]

I can't say I get dramatically better performance. I have a very similiar setup, i.e.,G5 dual 1.8 early version, osx 10.3.5, Logic 6.4.2, & 2 uad cards. I can get a little above 50%. Past 60% I get dropouts & stuttery playback similiar to you. I've tried everything. I'd LOVE to utilize the room I have left.
Mark Miller

 

[UAJames]

Hi Mike,
Out of curiosity what are your Logic process buffers set to? You will want either medium or better yet large. That could be the difference there if you set it higher, the key word their being could Also, just for grins, take out any RAM so you are 2 GB of RAM instead of 3.5GB. Nothing techinical behind that at all except it have noticed that in many cases where people are having unusually bad experiences with G5/UAD-1 many of them have 2GB+. I seriously doubt it would really have any effect, but it could be just one of those things.

Also this is directed mainly to Mark, but if you have 2 UAD-1 cards and your meter shows 50% that is 50% of 2 cards, where as Mike is only getting 50% of 1 card. Also keep in mind the G5 issues deal mainly with the number of UAD-1 plugins in use and not directly related to the DSP usage of the card, which is what the UAD-1 Meter is showing.

 

[egorjazz]

Hi All!
I´m not on g5 but some times ago i was in similar situation.
My setup:la6.4.2,Os10.2.6,Motu 2408mk3-pci424,1.25gb ram,external fw LaCie D2 Hd 120mb.
What i discovered is:
1.Process Buffers.Very Important in my case.Large did not work for me at all-drop outs during play back and mixdown.Even with just 4 mono tracks(piano LR,bass,vox),2 reverb buses,1 piano subbus.Uad-45%,logic-10%.....
Medium-great!Right now i´m mixing a song with 8 stereo traks,2 rev busses.Uad-92%,logic around 60%.Everything smooth..
2.Be careful with were you put uad plugins.The worst situation for me is when i open large reverb(space designer) on some bus and than add some uad plug(pultek for example).Well,it´s crititical on higher cpu loads.
Also,i`m not a big fun of mixing uad plugs with other plugs on the same channel.
Hope this helps.
Best regards!
Igor.(or Egor,as u want)

 

[HockeyMike]

Yesssss!!!! Eureka!!! and so on!!

Egor hit it on the head with the process buffer. When I switched it to Medium, I was able to get up to around 75% with no stutters whatsoever. It was pretty much all or nothing, though, since when I added another plugin that put me at 80% I got a huge \"Powered Plugins Error-UAD not responding\" message. But, to go from under 40% to close to double, that is a big step.

Anybody know if it matters if the \"Larger Disk Buffer\" checkbox is ticked or not?

Egor: When you gave the example of a bad situation with opening space designer on a bus and then adding a UAD plug, were you talking about putting that UAD plug right after space designer on the SAME bus channel? Just curious...

James: I'd like to hear a little more about what you've observed regarding G5 problems being related to the number of UAD plugs as opposed to DSP usage % on the meter, since that's the first I've heard regarding that aspect. What range of plugin numbers are \"typical\" among users? (In the particular song I was having trouble with I had 23 plugins, mostly mono, pretty much half Cambridge and half LA2A/1176). Are certain plugs in quantity more prone to overloading things than other plugs? If it's a question of quantity, does it make much difference if they're stereo or mono? And how about location (track, bus, aux, output, etc)?


Thanks again everybody...

 

[UAJames]

Hi Mike,
The reason the G5 issue is effect more by the number of plugins in use rather than the DSP usage is that the G5 issue is related to bandwidth usage, and each of the UAD-1 plugins use the same amount of bandwidth. For each plugin, data is transferred to the card at the same rate, but some of the plugins alogorithms use more math than others, and those are the ones that use more DSP, so DSP and bandwith usage are not directly related to one another. So you can actually have more problems on the PCI-X G5s (G5s using the AMD-8131 PCI-X controller) with a large number of \"small\" (non-DSP intense) plugins than you would with just a few \"large\" (DSP intense) plugins which would show a high usage on the UAD-1 Meter. It does make a difference if they are mono or stereo. Basically it is all based on mono data streams, so a stereo plugin will be 2 mono streams and therefore x number of stereo plugins uses more PCI bandwidth than x number of mono plugins. This was the same on a G4, but the AMD-8131 in the G5s is what is making the problem. If you think of the PCI-X controller as a PCI traffic cop, the AMD-8131 is like Mr. Magoo directing traffic I don't have any specific plugin count numbers for when you starting to run into problems because it varys between systems and depends on your type of sound card, other PCI devices, and sometimes other peripheral devices (FW, USB, etc).

 

[DBS]

Hello UAJames,

Is there any solution in the future for this problem (like software updates for UAD Card or firmware updates for G5)?

Or is this an issue without any solutions?

 

[UAJames]

We are still working with Apple on resolving the problem and as of right now I don't have an ETA on when a fix will be in place or even what kind of a fix it may be. We have just been doing what we can to workaround the limitations and get the best possible performance for our G5 users and obviously we don't want to just leave it as it is, especially with more and more of our users moving to the G5s, but it's not an easy fix :-(

 

[egorjazz]

Hi Mike!
I´m glad to hear u got it right!
:lol:
-----
Egor: When you gave the example of a bad situation with opening space designer on a bus and then adding a UAD plug, were you talking about putting that UAD plug right after space designer on the SAME bus channel? Just curious...
-----
Yes,on the same channel.Generally the escenario is when you open somthing that eat a lot of cpu(SpaceDesigner,Altiverb,MoogModular..) and than put an uad plug.I feel that on busses its much more critical than on audio channels.
Cheers!
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