How much CPU do plugins' GUIs use?

[Dengus Squatburg Jr]

Is it normal for plugins with fancy GUIs to increase CPU load dramatically and cause reaper to pop, click and stall?

Reason I ask is that I downloaded some of Stillwell and Schwa's excellent VST plugins to give them a try on an existing project. They seem to work great, but I noticed that the CPU load jumps from about 40% to 60-70% when I display them with their fancy white-tie designed UIs. For example, the Pshycho Dither plug increases CPU load dramatically (20% minimum), but when I toggle the "UI" button so that the graphical interface is replaced by simple sliders, the CPU drops again and everything works smoothly. Similar with Stillwell's "1973" and "Event Horizon", as well as plpugins like Voxengo's "Span", to varying degrees. These plugins all have either vu meters or frequency displays (ie moving stuff) in common. Maybe that has something to do with it...?

So it seems apparent that the plugin itself isn't hogging the CPU, just its UI. Even so, I would have thought that at 60-70%, there still should not be pops and clicks...

I'm thinking that maybe my video card has something to do with it. Anyone got any clues? Is there some setting I can change to overcome this?

Or could this be a bug with the Reaper 2.0 beta, as has been suggested elsewhere?

Note that I'm not suggesting that the plugins mentioned above are at fault, it strikes me as a display engine problem or something...

System vitals as follows:
P4 3.0ghz with "hyperthreading"(whatever that is...)
ATI Radeon 9800 video Card (128mb)
Edirol FA-101 - latency adjusted to 10ms
1.5 gig RAM
Windows XP SP2
Reaper installed on a clean partition with very little other software to get in the way.

(Sorry about the long post)

[stringtheory]

Hey Dengus,

I've noticed the same problem with stillwells' plugins as well as a few others, and also the same problem while moving the fader, pan, buttons etc. I get huge spikes in cpu, pops and clicks, occasional stutters. Hope someone has an idea, 'cause I really dig the 1973 eq. I've tried different buffer settings with the card as well as within reaper, no change.

My setup is an XPC C2 which also has hyper-threading. Perhaps HT is a clue?

Reaper 2.0 beta 2
P4 HT 3.2GHz
2 GB DDR400 RAM
(2) ATA 133 HDs 7200rpm
Windows XP Home SP1
NVidia GeForce MX 4000 64MB
M-Audio Delta 1010

[Dengus Squatburg Jr]

You might be on to something there, stringtheory...

I've tried disabling hyperthreading (makes it worse - which is expected), changing buffer settings, thread settings in Reaper, installing latest Radeon drivers, and it still happens.

As I understand it, Hyperthreading, sort-of, "fools" the software/os into thinking there are two CPUs. Maybe this is causing some kind of imbalance in the system. I'm sure someone in the know will correct me.

And I concur about 1973 - awesome on drums! Just a shame I can't get it to "play nice"...

[sstillwell]

Have you downloaded the latest versions of our plugs? We've made HUGE improvements in GUI CPU use.

Anything with meters or moving parts will chew up more than one without, but it shouldn't be THAT bad. At its worst it was using about 25% on an Athlon XP 2100+...a P4 3.0 GHz should have just smoked it.

With the latest version of 1973 running on my XP 2100+, I literally can't tell the difference in CPU use with the real GUI or the host UI displayed. I know there IS a difference, I just can't reliably measure it.

Scott

[sstillwell]

Also,

Shoddy video drivers CAN be a major pain. Sometimes video card manufacturers will set their drivers to set their buss priority SUPER high, so that they can get high framerates for games. Unfortunately, that sucks dog nads for audio I/O performance.

Google things like DoubleDawg, PCI Bus Latency Tool, stuff like that. You'll find tools to help manipulate your video card's latency back down to a reasonable value, which will help with more than just stillwellaudio plugs.

Scott

[Dengus Squatburg Jr]

Thanks for the quick responses, Scott.

When were the plugs last updated?

Also, 1973 isn't so bad, on its own (I'll have to take another look at the CPU numbers and get back to you). A big culprit is the "PsychoDither" plug, which jacks up the CPU enormously, then if I display 1973 it just kills it off.

Again - I don't want to give people the impression that these plugs are in any way inefficient or the problem, as I'm sure it's something to do with my computer...display settings or whatnot...

I've tried both DoubleDawg and PCI Bus Latency Tool, but really don't know what I should be adgusting. In any case, those two applications show me different latency values, and PCI Bus Latency Tool only displays my "Secondary" display driver ( the ATI card has two video outputs), which I am not using. Are there other latency values that I should adjust other than display drivers anyway?

[schwa]

I'd note a few things.

- This is definitely not a Reaper issue, FWIW. Plugins are in charge of drawing their own GUIs.

- A plugin with a gui that's just sitting there shouldn't use any extra CPU, no matter how fancy it is.

- Stuff moving on the screen does cost CPU. The more pixels moving, the more CPU it uses. (If you really want to see a CPU spike, try dragging a window around.)

- For visual analysis plugins like SPAN or Schope, all the work IS the GUI. The analysis doesn't even happen if the GUI isn't open.

- Definitely look up the Double Dawg app, and Scott's other links. Huge video driver latency can kill audio performance.

- For Psycho D, I admit the GUI is fairly gratuitous. It's useful when setting parameters to see exactly how the signal and noise spectral density compare, and it's pretty to look at, but once it's set, it does its work just fine if you close the window completely.

- Having said that, I run a P4 3.0 just like you, and the GUI on Psycho D costs maybe 5-10% extra CPU. If that 5-10% is critical, by all means close the window.

[Dengus Squatburg Jr]

Thanks schwa, and I get what you're saying. If I toggle the UI, or close it the plugin barely registers on the cpu. It's just that a 20-30% difference strikes me as excessive. Obviously my video card is hogging things more than it should, so I'll have to mess around with those latency apps again when I get home (Unfortunately I can't post screenshots or more specific detals as I'm at work...cyberbludging...)

[sstillwell]

Originally Posted by Dengus Squatburg Jr

When were the plugs last updated?

Some as of 2 Sept, others as of 9 Sept. I'm testing another build right now that has some final tweaks and should go up within another day or so. We don't move as fast as Justin does, but we're no sluggards, either.

Originally Posted by Dengus Squatburg Jr

I've tried both DoubleDawg and PCI Bus Latency Tool, but really don't know what I should be adgusting. In any case, those two applications show me different latency values, and PCI Bus Latency Tool only displays my "Secondary" display driver ( the ATI card has two video outputs), which I am not using. Are there other latency values that I should adjust other than display drivers anyway?

You should really google the subject, there's LOTS of material out there on PCI buss latency. Usually you can tell if a card is a video card with a sucky driver because the latency will be set up above 200, or even 250. Try dropping it down to about 60-90 and see how it behaves. If you have more than one video card, adjust the latency of both, whether actively in use or not.

As far as changing other values...I'm really going to have to suggest that you read up on the subject...there are so many system-dependent variables that you just sort of need to wrap your head around the subject and then adjust the system until it works right for YOU. That may mean not doing ANYTHING, but I doubt it.

Hope that this helps a little...

Scott

[Dengus Squatburg Jr]

Sure does - thanks again for taking the time, gentlemen...

Researching latency as we speak, and have already improved my understanding of it.

Rumour has it that ATI cards override latency settings to be 255 by default. Am I correct in understanding that if, say, my audio interface is set at a lower value, the video card will get the lion's share of the cpu's efforts? Therefore, if I can lower the video card's latency, it will start to behave better?

Still wondering why the latency tool only report my "Secondary" display (both display outputs are on the same card)... maybe I should just go out and buy a new card....

Time to start dicking around with the ol' confuser again and figure out what's going on....

[sstillwell]

Nope, doesn't have anything in particular to do with CPU use...it's a measure of the priority assigned to who gets to use the PCI buss (and even AGP cards, but NOT PCI-e, which uses a different buss structure). The numbers actually have no absolute meaning, but they are relative to each other...a value of 255 is going to take priority over darn near everything, all things considered. The data from other cards and ports WILL get delivered, but it may not get delivered in a timely-enough manner to stop dropouts and stutters.

Hope that helps.

Scott

[schwa]

Dengus, I just updated Psycho Dither with a new version that uses much less CPU (there's less detail in the frequency drawing, though I doubt anyone would notice). You might see if it helps you out. CPU use is down under 5% on my PC (which has the same specs as yours).

http://www.stillwellaudio.com/?page_id=27

[Dengus Squatburg Jr]

Ok schwa, hopefully I can download and try it tonight when I get home. If not, it'll definitely be in the next day or so. I'll let you know how it goes. Thanks.

[Dengus Squatburg Jr]

So I got a chance to quickly mess around last night.

The new version of Psycho Dither was an improvement, negilgible difference in CPU use on a "clean" project (1 track, no other effects) when the GUI is toggled.

However, I still get a huge jump of at least 20% and stutters on a large project with lots of plugs.

Adjusting PCI latency seemed to help marginally using DoubleDawg, couldn't tell with PCI Latency Tool.

What I did find, however, is that if I set the thread priority to "highest" and set the number of "Audio Reading/Processing threads" to 3 or 4 (default is 1 per processor, 2 on my system) in reaper's Buffering settings, the clicks and pops are pretty-much completely gone, although this does cause the CPU to jump a fair bit.

For example, in the project described above, the CPU jumps to well over 80% (with Psycho Dither, Voxengo GlissEQ and 2 instances of Event horison displayed), but the audio runs almost seamlessly, where prior to adjusting the above settings, it would crack and pop like crazy in the 50's.

However having all these plugs displayed at once is not a typical scenario. I'm happy if it runs smoothly with one plugin displayed at a time, so it's all good! And when I close the plugs, back down to 45-50 it goes...

I also noticed that when the going gets tough, the display becomes slighly jerky (pauses slighly every second or so), rather than the sound, so it looks like the sound is getting priority over the display. A good thing in my book... Perhaps this is DoubleDawg doing its latency timing thing? Whatever the case, this is the right way around in my opinion - sound takes precedence over graphics.

In any case, it looks like I'm having success in solving this issue, so thanks guys for the guidance and hopefully this might steer someone else who's having similar issues in the right direction.

Cheers

Dengus

[fluffy]

For what it's worth, on my machine, the Stillwell Audioplugins use no more cpu (at least no discernable amount) with the GUI turned on than with it turned off.

AMD64x2 4200+
2G ram
NVidia Onboard (shared) Video

[Dengus Squatburg Jr]

Thanks fluffy, that confirms my suspicion that something's not quite right with my system, as I'm still getting these big spikes. But at least I've managed to curtail the pops and clicks.

I still suspect its got something to do with the ATI Radeon card....I might see if my motherboard has an onboard video device and see if that changes things.

[funkster1]

Dengus,
I'm using an old ATI 7000VE/64 MB which is also clogging the PCI bus.
I'm using a tool called 'LtcyCfg2' to adjust this (google it up)

I had to put my video down to 32 and my audiocard up to 160/192 to smooth things out.

With that and some Reaper settings like 'Thread Behaviour/Priority' adjusted plus the 'Advanced Disk I/O Options' I got it going alright on a (t)rusty AMD XP 2200+.

I have answered to someone regarding my settings in another thread, mybe you could find some useful settings there as well?

http://www.cockos.com/forum/showpost...88&postcount=5

Cheers
Raphael

P.S.: I did a google search myself for the homepage of LtcyCfg2, while I didn't find it, there was a lot of noise about some mal-/spyware called just the same, so I uploaded a zip to download, which is 100% clean (though always test/check yourself).

http://rapidshare.com/files/55651817/LtcyCfg2.zip.html

[schwa]

Dengus, and whoever else,

I added some precalculation code that makes a major CPU efficiency improvement to all my plugins. Psycho Dither, on my PC, now uses only 1-2% more CPU with the GUI open and drawing the real-time frequency graph than with it closed.

But any extra CPU can be the last straw on the camel, so (with White Tie's help) I also added a button on Psycho Dither to toggle the real-time graph display on and off. If you switch it off, there should be literally no CPU difference between having the GUI open and having it closed.

I hope that helps you out! And thanks for the feedback on this, I'm happy to do any work that makes the plugins more usable for more people.

[Dengus Squatburg Jr]

Thanks Funkster and schwa.

Funkster - I already spotted your other post and have saved it in anticipation of trying some of your settings. Just haven't had time (busy painting the house all weekend!) I'll report back with any improvements.

Schwa - I did get a chance to try Psycho Dither on a friend's computer - cpu change was negligible with GUI on. Definitely a problem with my setup...