UAD and spiking- heads up

[dweiss]

I thought I'd post this information that I discovered the hard way yesterday. No doubt some of are already be aware of it but it may save someone some troubleshooting.

I was working on a project with about 30 tracks and a couple of VIs, not huge but not small either. At some point when I was tracking vocals I started to get erratic spiking which I couldn't associate with anything in particular that I had done to the track recently. The spiking seemed to be related to DFHS because when disabled the problem was reduced significantly. The weird part was that the sequence would play normally for a minute or two and then the CPU meter would start to climb into the red and stay there, causing distortion etc, and then run normally again.


Of course I needed the drums so I started looking for other problems that could be the cause. I reduced my bussing, merged soundbites, removed a VI and some native plugs but the problem persisted.

Finally I noticed that removing a UAD plug (the Neve demo that I was playing with) completely normalized the system again. The CPU meter was cruising along at 30-40%. I put the plug back in, spikes returned. On opening the UAD CPU meter I discovered that with the Neve plug I was running the card at 90% CPU. Without it I was at about 73%.

So, apparently the UAD card maxes out at somewhere around 80%. Any higher load than that and things go crazy. I never would have suspected that maxing out the card would affect the performance of the whole system, but it does.

Now, the dark side is that I've really been loving the Neve plug but may have to look at Native alternatives since apparently that's where I have more headroom.

Hope this saves somebody some grief.

G5 Dual 1.8
DP 5.01
OS 10.4.7

[IO]

i own all of the UAD-1 plugs..., i put DP on the shelf for now, but it might be a demo thing because the full version did not do this and i have the same machine you do.....

[dix]

Any reason you haven't bumped up to 5.1? I'm wondering if you'd see any difference.

[chrispick]

So, apparently the UAD card maxes out at somewhere around 80%. Any higher load than that and things go crazy. I never would have suspected that maxing out the card would affect the performance of the whole system, but it does.

You can minimize these spikes by switching our Work Priority to Medium or Low. Even though the UAD-1 processes its own effects, it still needs to be addressed by DP and your system. Switching DP off High Priority tells your box CPU it's okay to communicate with non-DP resources while addressing DP instead of only after.

Try it. It works.

Now, the dark side is that I've really been loving the Neve plug but may have to look at Native alternatives since apparently that's where I have more headroom.

FWIW, I think the SE versions of the Neve plug are pretty useful. They'll allow you more instances, thus giving you a little more plug mileage.

[grimepoch]

This is a known issue described on the UAD site and is completely related to the AMD chipset issue. I have a dual 1.8 and have the same problem. DO NOT go above 80% (or just get a second card).

Hopefully this will be gone with PCIe on the MacPro.

[dweiss]

I can't find the delete option for this forum.

[dweiss]

Thanks all for the replys. Interesting about the work priority Chris. But wouldn't that affect performance in some other way?

Dix,I haven't gone to 5.1 because I don't own an Intel mac and I have fear and loathing that half my plugs won't work once I do.

Grime, I thought the dual 1.8 was not an AMD machine, one of the reasons I chose it actually.

IO, the demo and licence are one and the same. The only difference is the license.

[chrispick]

Thanks all for the replys. Interesting about the work priority Chris. But wouldn't that affect performance in some other way?

Not in my experience. I mix at high buffer rates (1024 and above), so most real-time DP functions are no longer in play anyway.

I haven't gone to 5.1 because I don't own an Intel mac and I have fear and loathing that half my plugs won't work once I do.

The only plugin problems I ran into with 5.1 were MAS-related. DP has updated their MAS plug handling. If you're using a MAS version of a third party plug, it may prove incompatible (unless they've updated as well as Altiverb has) . However, for me, all AU versions of third party plugs are working great. In some cases, I had to delete their MAS bundles, but thereafter, all was cool.

[giles117]

The best solution to the UAD spike issue with a PCI-X G5/AMD chipset is a magma. As you may note on the UAD site I and others manage 90 + % with a multi UAD/Magma card setup.

Card inside the G5 is HELL....

[dix]

Dix,I haven't gone to 5.1 because I don't own an Intel mac and I have fear and loathing that half my plugs won't work once I do.

To be clear, 5.1 isn't just for IntelMacs. It seems much more stable on my system than 5.01.

[rainmaker]

Hey giles117,

How many uad cards can you effectively run from a magma chasis? I'm running two inside my dual 2.5 G5 but wouldn't mind adding a third or fourth if the system can handle it. I know the individual uad cards can handle it, but how much data can be sent back & forth through the one bus to get to the Magma?

Thanks,
Rainmaker

[Hide]

The best solution to the UAD spike issue with a PCI-X G5/AMD chipset is a magma. As you may note on the UAD site I and others manage 90 + % with a multi UAD/Magma card setup.

Card inside the G5 is HELL....

Am I lucky? because I installed 3 UAD-1 cards into my dual 2.5GHz PowerMac.
So, I have no empty slot... my next step is using Magma that I'm thinking.
But I don't have any bad experience with it even my mac has AMD chip of PCI controller.
Very smooth and very stable.

By the way, I'm using dp5.1 now.

[dweiss]

Good to know that 5.1 is generally stable and compatible with current plugs. I guess I'll look into that sometime soon.

Thanks again for the good advice everyone.

[giles117]

You can max out cards in a magma...

and Mr Dual 2.5 Glad you are having success.

I never managed more than 8 or 9 1176's before my G5 started spiking out.

Perhaps Apple made some subtle changes to the arch. with the Dual 2.5 Machines.

Where I have dumb issues is my powercore disappearing act cards. But then I have 2 of them and never used more than one, so I slapped one inside my G5, along with my PCI-424 and the magma Host. I Wish apple would go back to 4 Slots..... Even with teh double wide Video deal gimme a 4th slot for expansion.

My Dual 867 had all of it's slots used. At least with 4 HD bays I can eliminate the need for my SATA card.

Cant wait till September and I can buy the new Puppy