Multimedia Production Forums

I'm using my Sony VAIO NS21 laptop with Vista together with a E-MU 0404 USB interface for live music, so realtime performance is very important. So far it works quite well, even with the lowest latency setting (2ms).

However, periodic CPU spikes occur every ~17 seconds, where the CPU peaks at 50-70%. So, when I'm running VST's which use > 20% (like Truepianos), sometimes pops & clicks occur.

Some observations:

* The peaks only occur when I'm using audio software (Ableton Live / Reaper / EnergyXT)
* In that case the peaks always occur, even when no VST's are loaded and the software is idle
* Higher latency settings do not have influence on the occurance or height of the peaks
* I've tried various optimizations, Vista should be completely optimized for realtime audio now

The above leads me to the conclusion that maybe something is wrong with the E-MU ASIO driver? Anyone else has ideas what to try next?

See a picture of the periodic peaks below:

Have you disabled your network cards?

Yes, I've disabled both network cards as well as the internal Realtek sound card and the internal webcam.

By the way, according to Process Explorer the peaks are caused by "Deferred Procedure Calls".

I just reminded, Microsoft ACPI-compliant Control Method Battery can cause some glitches too, that would be my next guess. If you haven't done so already, try to disable the power management stuff in the hardware manager, or at least the part related to the battery monitoring (Microsoft ACPI-compliant Control Method Battery).

... and if you have any Sony Support software running, "kill" it... and the Windows backup thingie... can't remember what it's called, where it writes an image to a hidden partition... I must be gettin' old...

Sounds like you may be dealing with a DPC latency problem.

Run the DPC latency checker. You can download it here:

http://www.thesycon.de/deu/latency_check.shtml

Also read the info on the download page that explains very well what those DPC latencies are about and how to best identify and eliminate the culprit(s).

As you already have the onboard networking gear, the Realtek sound and the webcam off, the DPC latency checker can tell you if there's another component causing latency spikes that spell trouble for audio work.

USB hubs (external or internal) can be troublemakers, too.

Just as vital as those DPC latencies is, of course, that your E-MU has an IRQ of its own that's not shared with anything else (especially not the graphics chip/card), so make sure you take a look at your IRQ table and maybe post it here for all of us to take a look.

Johnny, jmail and TwoRocks thank you very much for your help so far!


My first guess was also that it is probably related to power management. I disabled all power management, including the "Microsoft ACPI-compliant Control Method Battery" (had to go to device manager --> view by connection for that) but nothing changes in the behaviour unfortunately.


I killed everything related to Sony and I disabled all scheduled tasks (like defrag, restore points, etc.).


I've run the DPC checker. Here are the results:

Running audio software (idle), with 0404 USB switched on:



Running audio software (idle), with 0404 USB switched off:




I can imagine that. I've tried different USB ports on the laptop but the behaviour is the same everytime.


Here is the tail of my IRQ table (sorry, in Dutch):



It looks like there is some sharing going on? For example with the video card (probably a bad thing!). Anything I can do about it? Might this be the problem?

Oops... Hum, I would try to install XP if I were you. I recently installed Win 7 in my laptop, and the performance with my 0404 usb is not as good as with XP (which I kept on another partition for my music stuff).

Well, it looks like USB is using IRQ 16 and IRQ 19, so no matter where you plug your 0404 in, you have one possible troublemaker, each: the graphics chip on IRQ 16 (which you can't turn off, natch), and the SATA controller on IRQ 19 (which you can't turn off, either). Looks like you're caught between a rock and a hard place.

However, it looks like you still have your HD audio on (IRQ 22) -- you should definitely turn that off in the BIOS, as two sound cards / audio interfaces active simultaneously is never a good thing.

Also, if you don't need firewire (IEEE 1394), turn that off, as well -- one device less "battling over" IRQ 16.

Your DPC latencies with the E-MU on definitely don't look good.

Try disabling the remaining components, go through all available USB ports again, and see if you get one scenario where the DPC latencies don't produce that strange "comb" pattern.

If you still get the same, trying a different OS seems like a last resort solution. XP would probably be preferable (if you can get all the drivers for your lappy's onboard components), but if you do a full back up and hard drive reformat, anyway, you might as well set aside an extra partition (some 35-40 GB should suffice) for the Windows 7 release candidate, just "for kicks".

Other than that, I'm fresh out of ideas...

But wait: I just noticed that USB is also using IRQ 23, and there's nothing else on there "competing", so if you plug your 0404 into one of those ports that are using IRQ 23 you would have eliminated the IRQ conflict problem.

And before you ask: sorry, I don't know of a method to identify which USB port use which IRQ -- anybody?

Thanks, I will try that as a last option. So far I have not found a "downgrade" option for my VAIO model, so I will probably have to buy a fresh Windows XP installation disc.


I would if I could, but unfortunately modern VAIOs only seem to have a very basic BIOS where you can only change your password and boot options. I will disable as much components in Windows as possible, though.


Thanks, will try that. Anyone else with Windows Vista seeing the same behaviour? Looking at the comb pattern, it seems that clicks & pops could easily be avoided by the OS if it would spread the CPU usage more evenly. Or, this could also be a "bug" in the EMU driver. Could someone with Windows Vista take a look at their DPC checker results?


I will go through all the ports again!


My guess would be that you could plug a device in an USB port and disable them in Windows one-by-one until your device stops working (then you have the right one!).

Yeah, that sounds like it could work...

But I noticed something else that leads me to believe that your problem is not an IRQ-related one: the DPC spikes in your bottom screen cap (with the E-MU off) occur roughly every 15 seconds, and that's also roughly the interval of your "comb" pattern when the E-MU is on.

So there's definitely some misbehaving VAIO component causing it, and with the E-MU on, things get worse.

As the N.O.S.Y. folks don't give you all the tweaking power in the BIOS that you should have, try disabling as many items in device manager as possible. You'll obviously have to leave the graphics and SATA on, but turn off everything non-essential, then run the DPC checker again (with the E-MU off) and see whether you still get the same spikes every 15 seconds or so, or wether they're gone.

If they're gone, you're in luck, and you can then turn them back on again, one by one, until the spikes return, and then you'll know who's been misbehaving...

If you still get the same spikes even with just the "bare essentials" running, a newer BIOS might fix the troublemaker, and if there's no download available from the N.O.S.Y. site, you can e-mail support and ask them for a custom BIOS. Some reputable motherboard makers actually are very responsive in that regard, while you never hear back from others.

Good luck!

I average 25~47us with DPC Latency Checker, although I use a PCI card, you shouldn't be getting latency through your USB that bad. I trust you are using a USB 2 port for connection. Make sure any onboard audio is disabled. If this is already covered then I apologise for mentioning this.

When the EMU is off the spikes are not really periodic (although it looks like it in the figure), but indeed something is happening.


I disabled almost everything, but no luck! But I'm pretty sure that a device still may cause interrupts even though it is disabled in Windows (interrupts are hardware-controlled right?). So I will have to disable them in the BIOS, it is a shame that Sony won't let me


Good tip, thanks. I contacted Sony about a BIOS update.


Thanks!


Thanks for checking. That is indeed the amount of latency I get when the EMU is off (besides the single spikes every 10-20 sec) so I agree with the rest of you that something is wrong.

The ports are indeed USB 2.0.