White noise from recording

[Cswitzer]

I have been having an issue using Digital Performer lately and was wondering if anyone could offer some support for me. What I have seen is the CPU jump to 100% and from that point forward there is nothing but white noise. The funny thing is that the CPU monitor in DP does not max out, just the CPU monitor as shown in the activity monitor on the Mac. I found that the initial recording I do when I open DP startes out ok, then when I stop recording the Mac's CPU goes through the roof, all future recordings then tend to max the CPU out while recording, but not always. This issue does not happen every time I record but does happen about 90% of the time. I tried a bunch of things (listed below) to try and pin point the issue but have had no luck. I have not seen any performance issues with the Mac with any other applications, it seems to be isolated to DP. One other key point is that this seems to happen when I am recording live in a very loud room and not so much if I am recording single instruments. Has anyone ever seen issues due to vibration (maybe hardware related i.e. PCIe card vibrating causing audio signal to drop out?) I am hoping someone can help shed some light on this for me.

Setup:
Mac Pro 2 X 2.66 Ghz Dual-Core Intel Xeon
OSX 10.6.8
7GB Ram (667MHz DDR2 FB-DIMM
Digital Performer 7.24
Glyph GPT50
Motu 24i/o

Additional info and what I have tried so far:
I thought it might be a hard drive issue so I replaced the audio hard drive with the Glyph GPT50 with no change
I thought it might be a memory issue so I pulled half of the memory but it still happened
I replaced the memory and pulled the other half of the memory sticks but the issue remained
I tried using DP 7.22 and the issue seemed to stop for about a week but then came back
I am not playing through any FX while recording and have a template setup that has no plugins running while recording.
I am recording about 24 tracks at a time (I have been recoding this many tracks at once without issues for years now)
I have not made any software updates recently
No other programs max out the CPU like DP does
I am recording with a sample rate of 44.1khz
DP's buffer size is 1024
DP's Host buffer multiplier is set to 1
DP's priority is set to High
Input monitor mode is set to Direct Hardware Play through
I am using 20 stereo busses in the Studio Settings (which was higher but I lowered this to see if it would help but it did not)

[mikehalloran]

7G RAM only? You need more. That's my first thought. You could also have more than one bad stick.

DP 8 in 64bit uses RAM far more efficiently. Not only well worth the upgrade but you will also have access again to Tech Support.

It can certainly be a hard drive issue as well. Read this thread and take a look at your background processing preferences. RAM and hard drive speed both have an effect.

http://www.motunation.com/forum/viewtop ... =1&t=52507

My gut says that something on your Mac has a memory leak issue. Could be a plugin or something else. The best way to isolate is to re-boot, run the Activity Monitor and see what is spiking your CPU. I have had freeware and old commercial software be the culprit. An innocuous little bit of freeware called Temperature Monitor from Bresink gave me major headaches until I got rid of every last bit of it (what a PITA!).

TechTool Pro is capable of finding hard drive and memory problems that other utilities cannot. If Apple's RAM test and Disk Utility say your RAM and HD are good - but TTP says bad, believe TTP. I take care of a lot of Macs and have solved many problems by replacing drives and RAM that weren't bad enough to fail Apple's tests.

To properly test the drive in your Glyph, you must pull it out of the housing and mount it in your Mac Pro - unless you are connected via eSATA. It will also run 3-5x faster than FW400/800.

If the drive in your Glyph is PATA/ATA instead of SATA, it's old and should be retired anyway except as a Time Machine backup. In any case, there is no way to properly test that drive in your Mac Pro.

[MIDI Life Crisis]

Update all audio & MIDI drivers?

Repair permissions?

Kill all plists?

[kgdrum]

7G RAM only? You need more. That's my first thought. You could also have more than one bad stick.

DP 8 in 64bit uses RAM far more efficiently. Not only well worth the upgrade but you will also have access again to Tech Support.

I agree the OP might have bad ram and should have more than 7 gig.
But as a registered user of DP doesn't he have tech support? I'd understand if he was using DP4 or DP5 as they are ancient history but aren't users of DP7 still supported?

[Cswitzer]

I contacted motu but they had no useful information for me. As for the memory, I was recording with 3 gigs in the past and had no issues other than DP responding slow. Monitoring the memory shows DP using the most but there is still plenty available when recording. I did order more memory (have not received yet) but I am doubtful that is the solution.

I purchased a new HD and had the same issue. I also did a fresh install of the OS and DP and the issue remains. I am going to try moving the Mac to another room to rule out a vibration issue and will try the new memory when it comes in.

I am feeling like this is a PCIe card issue but I would rather not send it back to Motu until I exhaust all other options first. Thanks everyone for your input so far!

[Cswitzer]

Thought I would provide an update. Turns out the the issue was due to the vibration from the guitar amps in the same room as the Mac. I removed the Mac from the room and it now records with no issues. The Mac was sitting on a raised floor along with two 4x12 guitar cabinets and the vibration that was induced into the floor must have caused funny things to happen inside the Mac. Not sure what was actually causing the failure but all is good now! Lesson learned, be careful how much vibration your Mac sees when recording

[Shooshie]

Serious vibration will cause a hard disk to crash!