CPU Overload using Post's "EMPEROR" Piano in Konta

[tjtracey]

I am running DP 4.61 on a PowerMac G5, dual 2.0ghz with 4.5g ram. While recording a single piano track (with only click) using PMI's Emperor in Kontakt 2.2, the CPU usage gradually builds over time and overloads somewhere in the 2 - 3 minute mark forcing me to quit recording. The same thing happens when I freeze a track in an existing project. It plays along fine for 2 - 3 minutes (gradually building in the CPU usage bar) and then overloads, forcing me to stop freezing the track. I use other (larger) samples with no problem of this sort at all.

Can anyone suggest any help? Anyone out there using this piano sample in Kontakt (in DP) that can guide me? I don't fiddle with Kontakt enough to understand it well. I wrote Michiel Post. His reply:

Well this is certainly not normal. You need to find out what exactly is causing the CPU to work so hard. First thing that comes to mind is the Kontakt Convolution effect. There are many settings in the Convolution effect that can be used to lower the CPU load. You can make the impulse shorter, you can lower the sample rate of the Convolution process and add more latency there. The other CPU intensive thing is the Overtones script. You can try to bypass it altogether just to check if that is causing the CPU flipping.

I'm not even sure what the "Kontakt Convolution effect" is or what settings to adjust.

Thanks for any help. Appreciate suggestions on DP settings as well as Kontakt settings from those of you who have resolved a CPU overload issue, even if you don't use Kontakt or Emperor.

[tjtracey]

Anyone have any general suggestions for overcoming CPU overload? Still looking for help...

Thanks.

[chrispick]

Does it only happen with Kontakt and that piano sample? Are you streaming the sample from disk (my assumption is you are)? Have you loaded the sample traditionally into RAM to see if the problem remains?

My half-blind assumption is you're streaming the big samples off a drive that can't keep up, so it's compoundedly taxing your CPU. Are you running DP, your OS and your Kontakt samples off the same drive?

It's just a guess though. Not much info to go on.

Also, how low is your buffer set? Often, 128 is the lowest practical buffer setting for tracking -- and, actually, 256 is more CPU-comfortable, although some users find it too slow in response (I usually don't). The lower the buffer, the harder your CPU works.

[Spikey Horse]

I'm not even sure what the "Kontakt Convolution effect" is or what settings to adjust.

In Kontakt click on the spanner in the loaded piano instrument to open the edit sections, you should see convolution reverb in the send effects section. You could try changing the preset or deleting the effect altogether. I don't know what the con reverb should be by defaullt as I don't own this piano.

I suppose there is a chance you changed the reverb to something wacky without knowing it and then saved it as part of the instrument, but it sounds unlikely to me to be the cause in any case.

Further to chrispick's suggestion, it might be worth checking the exact data path of the loaded piano - I'm talking about if you have the samples duplicated in two locations (say a good hard drive and a really crappy one) and have accidentaly browsed and loaded the wrong one.

[Shooshie]

To simplify: turn off all reverbs and effects in Kontakt.

Shooshie

[chrispick]

Any development here? Get the problem solved?

[dweiss]

It may not apply in your case but I had the same symptom when I was unknowingly overloading my UAD card CPU. For some reasong the computer CPU goes nuts when you overload the card. Removing a few plugs solved them problem. Just throwing that out there.

[chrispick]

It may not apply in your case but I had the same symptom when I was unknowingly overloading my UAD card CPU. For some reasong the computer CPU goes nuts when you overload the card. Removing a few plugs solved them problem. Just throwing that out there.

You can alleviate this problem by knocking your work priority down to low. This'll allow your CPU to talk to the UAD-1 card with better efficiency.

Try it. It works.

[dweiss]

Interesting. Are there any side effects of the low priority?

[Frodo]

Interesting. Are there any side effects of the low priority?

It's often a temporary compromise-- low priority allows for other non-DP items to benefit from more CPU, but of course, you limit the available CPU cycles in DP. Once you get the tracking done, you might want to readjust the work priority to a setting offering greater CPU equity to DP and other devices/plugs running concurrently.

for tjtracy:

I must agree with the others-- disable any luxurious fx while tracking, convolutions especially. Use a decent low-profile reverb if you can't stomach dry samples while tracking, and save your high end fx for mixdown.

Another thing to consider is how much data you have running through your various busses. If you are streaming Kontakt samples along the FW bus plus have an FW audio interface, it could be that infamous FW bus clog jamming the CPU. An internal or external SATA solution will alleviate some of the burden on the CPU.

Can you either limit the numbers of voices this piano uses-- to reduce them from, say, 32 voices down to 24 or even 28? Or can you get away with using patches that require fewer than the max number of velocity layers? While the former is a common optimization, the latter does offer a few caveats while opening up CPU cycles for better performance-- that is if and only if there are available patches with fewer velocity layers. The caveat, of course, quickly becomes one of a possible musical compromise, so this approach is not highly recommended if your piano track must run at full wack.

As long as you have Dual, you may want to consider at some point putting in more RAM. That way, you can run Kontakt "outside" of DP in standalone mode. Currently, DP, OSX, all plugins, and Kontakt (plus Emperor) are all competing for the same 4.5 GB. If, for example, you had 8GB, DP tops out around the 3GB mark, so you'd have 5 GB left for streaming Kontakt.

I know someone is going to chew me out for bringing up the RAM issue again!! But, it does keep the boat afloat in a pinch... With virtual instruments (those which run in standalone mode), it doesn't make sense to use half the available resources.

[blue]

I know someone is going to chew me out for bringing up the RAM issue again!!

Well, you've always got the friendly hobbit guise for cover.

As they say, RAM is the best bang-for your-buck upgrade you can make to your machine. I recently added 2 more GBs to mine and the difference is big.

I don't think anyone could reasonably fault you for good, solid advice.

[brett]

in Kontakt, go to options, advanced tab and turn the buffers to minimum. Slide the fader all the way to the left on both of them. I was having the same problem with Les Paul Custom performance preset. Works fine now that I lowered the buffers. This is a global setting and will not need to be touched again.