Crazy-high CPU usage in Cubase SX

cerendir

Hello everyone,

Haven't posted anything in quite some time here because, well, I haven't really felt like messing around much with kX since everything's been working like I want it to. Up until a while ago at least.

First of all I want to make something clear to avoid the "are you sure your computer is poweful enugh?" questions: I have used this exact setup since August or so without the slightest problem. So yes, my machine can handle the load and has been doing so happily for months. The problem I'm about to describe has reared its ugly head recently, maybe within the last three weeks or so.

And oh, if you're wondering why I'm posting this here and not on some Cubase forum, the answer is simple: I'm not a member of any Cubase forums and I know there's a lot of knowledgable people hanging out here. So sorry if this isn't strictly kX-related but I didn't know where else to turn.

As the thread title implies, my CPU usage in Cubase SX (2) has suddenly shot through the roof. Before this started happening the CPU meter would idle at perhaps 10% and it would go up to 30-35% tops under maximum load (5.33ms latency BTW). And we're talking just midi and VST instruments here, mind you; no audio tracks at all. But suddenly, or so it seemed, Cubase went from running like clockwork to being unusable. Now the CPU idles at 40% and shoots up to 80%+ when playing back. I get crackles and dropouts all the time and everything generally sounds like shite. And not only that; the meter also jumps up and down like mad whereas originally it would just sit peacefully at a certain level.

I have absolutely no idea what's wrong, I'm at my wit's end here. With no programs except for shell, firewall and mouse drivers running, my CPU hovers around 0-10%, which rules out (I think) that there's something in the background stealing cycles. If I check the task manager I can clearly see that it's Cubase and nothing else that's maxing out the CPU. I've scanned for viruses and malware with several different programs and found nothing. I've checked the device manager and event viewer for any hardware glitches and error messages -- nothing. I've moved my soundcard to a different PCI slot (originally it shared an IRQ with my gfx card, but that didn't use to be a problem before) and still no luck. I've tried several different versions of the kX drivers -- doesn't seem to make a difference.

Did I change something recently, you wonder? Well, yes and no. I reinstalled Windows maybe a little more than a month ago, but SX worked fine after that. No new hardware, no new programs that I can think of. I'm using the same drivers for everything that I used before the reinstallation. As far as I can tell this problem appeared right out of the blue, completely unprovoked.

Does anyone have any idea what might be going on here? This is driving me nuts and I would be very, very thankful for any suggestions.


Anyway, this is my system:

AMD Athlon 64 3200+, Abit KN8 mobo (nforce4), 1024MB RAM, 2 Samsung SATA drives (160GB & 250GB), Soundblaster Live! Value, Geforce 6600GT, Windows XP SP2, Cubase SX 2.0.0, kX drivers v. 3538j (though I've tried several other versions).

A typical Cubase project would contain a drumkit in sfz format (nothing huge, just 40 megs or so) plus a handful of VST synths, most commonly Synth1, augur, LightBag II, Crazy Diamonds, GTG JP7A and 4Front piano module. Mostly I also use two fx buses with Kjaerhus Audio reverb & delay.

cerendir

No one?

Maddogg6

did you chane 'mode' in the KX ASIO CP applet - some modes make mu CPU usage change..?? thats all I got sorry...

thomasabarnes

If you made no hardware or kX driver change, it sounds like you didn't setup as you once had things setup. You will do good to post your system specs! You said you reinstalled Windows;that could make a big difference. Maybe you have an ACPI windows configuration, now, and maybe you used to have a Standard windows configuration when Cubase and kX was working right for you. Some systems need to have a Standard windows config., and on those systems an ACPI windows config will cause you to see high CPU usage and freaquent drop outs when playing a project.

You need to try to have installed the same kX driver and windows config you had when it was working right.

Also you might want to take a look at Lex's Guide for setting up Cubase and kX: A Newbie Guide - "How to setup Cubase SX with KX"

And like Maddogg said, depending on what version of the kX driver you're using, you have to try the different driver modes in the ASIO control panel, you can see high cpu usage and drop outs when playing back a project using some of the different driver modes.

cerendir

I've tried a couple of diffrent modes but I haven't had any luck with anything but the default one. As some modes very effectively freeze up my computer it kind of makes you hesitant to experiment with it.

Uh, I did.

That would seem like a logical conclusion, but like I said in my inital post this did not start happening immediately after I reinstalled. It all worked fine for several weeks before this problem started.

I'm not willing to bet my life on it, but I'm 99% sure that I did have an ACPI setup previous to the reinstall, as I do now. But I'm going to try and switch to standard PC instead and see if that helps. But what are the downsides of running a modern machine in "legacy" mode like that? Will stuff like processor power management and stuff like that still work?

I do.

I've looked at it before and to my knowledge everything is set up properly. But I'll have another look just to be sure, thanks.

thomasabarnes

Sorry man, I was reading to fast and missed your system specs.

You should be fine with an ACPI config. But if all else fails, you might as well try Standard.

Can there be any problem with your Motherboard or some other hardware? Does all other programs run OK?

Have you made sure all your Drivers are up to date (Video aand motherboard, etc.)?

After noticing your system specs, I have nothing more to suggest, sorry.

cerendir

Well I'll be damned. I've solved it. More or less.

The answer was not ACPI, though it was something similar: processor throttling. When my CPU goes into power saving mode, the clock frequency is reduced by half... and a 1GHz CPU can't handle all the soft synths I have running. Thus the stutters and dropouts.

I've solved it for now by uninstalling the AMD CPU drivers... but it's not an ideal solution as the CPU will consume a lot more power (and run hotter) by running at full tilt all the time. The question is: why does the CPU remain in power-saving mode when Cubase is launched? I know for a fact that it didn't do this before, even though I had those drivers installed. As soon as I ran Cubase I would hear the CPU fan start spinning faster, just like when I launch a game. Hmm, something to investigate.

Thanks for your help guys. If it weren't for the talk about ACPI, I would never have thought of this

thomasabarnes

Good to hear it man. A little chit chat can sometime spark ideas or help in some way.

Good luck with your solving the other problem.

K1t4r0

Hi all, this setup is usefull with fruity loops too?