Choppy audio and slow loading

[Penderworth]

Hey guys,

I'm now the proud owner of a 2008 octa-core Mac Pro. I know, I should have at least gotten the 2009 model. I didn't do enough research. Oh well.

Anyway, I've noticed a bit audio choppiness in iTunes when I'm just scrolling around and in Logic Pro X when I'm creating music. It seems to happen when there's more read-write stress on the disk, but I'm not entirely sure. I plan to buy an SSD, but right now I just have the stock 1TB drive. I wanted to ask you what you think about this type of issue. I don't quite know where to start, but I do know the HDD's read/write is 110/100.

 

[Inutopia]

It shouldn't be happening, regardless of whether you have an SSD or not.

Questions:

Is the OS a clean install?

Does the issue follow you to a new user account?

When you open activity monitor, is there anything chewing up your CPU/RAM?

How much RAM is installed in the machine?

Do you have an external audio interface?

Does the disk report as healthy in SMART?

Have you run tests on the HDD?

 

[Penderworth]

It shouldn't be happening, regardless of whether you have an SSD or not.

Questions:

Is the OS a clean install?

Does the issue follow you to a new user account?

When you open activity monitor, is there anything chewing up your CPU/RAM?

How much RAM is installed in the machine?

Do you have an external audio interface?

Does the disk report as healthy in SMART?

Have you run tests on the HDD?

Clean install with a few things running. 4 GB of RAM in use, 10 GB installed. Nothing seems to be eating up CPU. It's under 10% load max. I tried an external interface as well and it didn't help. Smart seems fine, though I don't know where to look other than Disk Utility. I only ran a Blackmagic test to see its speed.

One other note: I was downloading some large files in Safari as this issue was happening. Could that be the issue?

 

[Inutopia]

One other note: I was downloading some large files in Safari as this issue was happening. Could that be the issue?

Nope, the music should never stutter because of other things on the system, at least not unless you were hammering it hard. I assume of course you're not talking about streaming music, just playing local files in iTunes to speakers that are physically connected to the computer?

I'll give you an example of a regular scenario on my old 2008:

Exporting 500 raw images from Lightroom, rendering a 200mp panorama, and listening to music in iTunes. it never stuttered even once under this load, and the CPU and RAM were both being absolutely pegged.

Anyway, so you're just using the onboard audio, that should be fine. Plenty of RAM, also fine. Nothing eating all the CPU either. At that point I'd probably want to look at the hard drive being bad, I'd try to use a different drive and see if that fixed it.

 

[liabeokgm]

good info,thanks for your sharing

 

[Penderworth]

Nope, the music should never stutter because of other things on the system, at least not unless you were hammering it hard. I assume of course you're not talking about streaming music, just playing local files in iTunes to speakers that are physically connected to the computer?

I'll give you an example of a regular scenario on my old 2008:

Exporting 500 raw images from Lightroom, rendering a 200mp panorama, and listening to music in iTunes. it never stuttered even once under this load, and the CPU and RAM were both being absolutely pegged.

Anyway, so you're just using the onboard audio, that should be fine. Plenty of RAM, also fine. Nothing eating all the CPU either. At that point I'd probably want to look at the hard drive being bad, I'd try to use a different drive and see if that fixed it.

Yeah I'm just locally playing music through iTunes. No streaming to speakers or from the Internet.

On your 2008, how much RAM did you have? Could my issue be a bad DIMM or the fact that I mixed 667MHz with 800MHz? I removed the 667 and tried just the 800 but it still happened. My way of testing things is to encode an MKV in Handbrake. Whenever I switched from iTunes to Handbrake or back the audio would stutter as if the CPU spiked. I will note that in this instance, the CPU load was at 7.5. Still, from what you're saying I should be fine.

I'm also running iStat to keep track of things. Nothing seems to be going on. I checked the Console and only found this error: USB Sound assertion in AppleUSBAudioDevice at line 4968.