Ultralite mk3 with Expresscard pegging CPU core @ ~100%

[LiqMat]

Hi folks,

This might be a bit wordy, but I want to give a "quick" background to my issue. Thanks for any help in advance.

First time here. Never have had any issues with my Ultralite mk3 FW until now. I recently moved my music production over to a laptop from a desktop. I don't know if any of you have noticed, but finding a laptop with Firewire nowadays is incredibly difficult. I went with a SIIG FW Expresscard instead. It detects my mk3 just fine. The SIIG card is using a Texas Instruments chipset which I believe MOTU recommends. My laptop has a 4-core i7-2960XM CPU which is the fastest mobile CPU right now. My problem is when I load Cue FX or anything to do with the mk3 one of my cores (usually the first core) gets pegged at 85%-98%. This is with nothing using the mk3 other than an app like Cue FX being loaded. If I load my host seq Ableton Suite 8 I get immediate latency issues on playback. I can play a few simultaneous tracks, but beyond let's say 5 or 6 tracks audio dropouts start to happen and that is with the SPB (samples per buffer) set @ 1024.

So I did some investigating around the web and noticed a few others with laptops and FW Ultralite mk3 units having the same types of issues. One thing I did learn it has all to do with the FW driver and not the MOTU driver in Windows 7 64-bit. One person in another forum states that MOTU's latest driver solved all his issues in Win7 64. Well, not me. I was using the standard TI 1394 OHCI driver that comes with Windows 7, but that driver pegs at 100% with one of my cores. I then tried the ubCore FW driver, but that does not support pro audio devices, just storage, cameras and networking devices. So I tried another suggestion that worked for someone having almost an identical problem that I was having. I force the Windows 1394 OHCI Legacy driver in Windows 7 64 down my SIIG Expresscard's throat. Well... a massive improvement in playback latency. Now my CPU sits at about 1-7% CPU usage sitting idle with Cue FX or Ableton loaded. I can also leave my SPB now @ 128.

Sounds great, but what I wanted to ask all of you using an Ultralite mk3 FW model is this: Is it normal for the CPU to have any percentage used by Cue FX or any app related to the mk3 while sitting idle? Mine now sits at about 1 to 7% idle with just Cue FX loaded. I would think there would be no CPU usage while sitting idle with no tracks playing, etc. I could be wrong and wanted to compare notes with what you folks are getting. Thanks for any responses. Unfortunately I never checked this when I had my desktop because I never had many latency issues with my motherboard's built-in FW port.

[torrentg]

Yes, it is completey normal for CueMix to use cpu time continuously, even when it appears as "idle".

I was the one that popularized the Legacy driver when I first figured out that it works flawlessly, as opposed to the normal Win 7 included 1394 driver.


As I always say, depends on the hardware. It has helped tons of users.

[LiqMat]

@torrentg:

Well, you sir helped me out tremendously. That advice prevented me from selling my UL mk3 and purchasing the hybrid model so I could use USB instead. Works perfect now and much appreciated. I would never have guessed to use a legacy driver like that.

P.S. - Just noticed I was calling CueMix FX, Cue FX. Isn't that lovely.

[psicopat04]

Hi folks,

....
I was using the standard TI 1394 OHCI driver that comes with Windows 7, but that driver pegs at 100% with one of my cores. I then tried the ubCore FW driver, but that does not support pro audio devices, just storage, cameras and networking devices. So I tried another suggestion that worked for someone having almost an identical problem that I was having. I force the Windows 1394 OHCI Legacy driver in Windows 7 64 down my SIIG Expresscard's throat. Well... a massive improvement in playback latency. Now my CPU sits at about 1-7% CPU usage sitting idle with Cue FX or Ableton loaded. I can also leave my SPB now @ 128.

Hello

today you save my life

Many many thanks from a french man !!!