"Hello Mike, when reading your web page, I noticed your question about the AudioAUUC kernel extension which should allegedly be part of the "Mac Pro Audio Update".

(In my notes in yesterday's post on the "Mac Pro Audio Update", I had mentioned I didn't see that extension listed in OS X 10.6.2 Apple System Profiler (ASP) extension list before installing the Audio Update, although the same version was already present in 10.6.2. And after the update it was listed in ASP's extensions (i.e. actually being loaded) but was the same version (1.0)/same last modified date, etc. - which made me wonder if that extension just wasn't being loaded/used before the 'audio update'.-Mike)

You are right: The AudioAUUC extension has nothing to do with this update. It was in fact part of the Mac OS X 10.6.2 package. Apple has published wrong instructions here.

(At the bottom of Apple's "About the Mac Pro Audio Update" doc, it says after the update is applied (w/required system restart) to verify that ASP's extensions list shows the AudioAUUC v1.0 extension. That seems to imply it was a new/updated extension - but it may just mean it's actually now being loaded/used after the update. (From what I saw, the latter is true.) And like many Apple updates, there's little details on what really was changed but my feeling is checking for that extension actually being loaded was a way to confirm their updater had been applied successfully. i.e. My guess is this extension is now being used (where it wasn't before) due to the other changes Marcel notes below.-Mike)

It is undocumented what AUUC stands for, but my educated guess is that this is the "Audio Unit Upstream Client" which seems to play a role when sending audio data to HDCP-protected devices.

What the Mac Pro Audio Update actually does is to upgrade
- the IOPlatformPluginFamily extension from version 4.0.1d0 to 4.0.2d0 and
- the AppleHDA extension from 1.7.9a4 to 1.8.3fc1.

The first extension contains a collection of drivers which control the different energy-saver states of Intel processors. The second extension contains a collection of drivers for audio chips complying with the Intel High Definition Audio standard.

After the update, playing audio over the integrated audio chips will no longer create the unexpected change in processor performance. The temperature behavior of the CPUs (which has never been a problem) does not change, you only need different programs (not audio) to trigger a rise of temperature values now.
Best regards, Marcel Bresink
http://www.bresink.de/"

Regardless of what they did, I'm just happy that simply playing audio in OS X with my 09 Mac Pro no longer ramps up temps and system wattage (110W+ rise from audio alone) as it did before. (The high wattage/temp increase from audio alone was not seen in Windows or Linux.)
And as I said yesterday, hopefully they'll release a similar patch for OS X 10.5.8. (BTW: Unlike 10.6.2, that extension does not already exist in 10.5.8.) I've updated my original article/tests on this issue from last Nov. to include a FYI about the Audio Update for 10.6.2.

BTW: A reader said the "Audio Update" also fixed the high wattage/high temps seen during Firewire transfers (I still see this in 10.5.8), but some Firewire audio interface users are reporting the "audio update" has caused a High pitch squeal when using Firewire audio devices.

"I just wanted to give you an update on the Sonnet Tempo E4P SATA card. They finally released the updated drivers for Snow Leopard a couple of weeks ago, and I've been giving them a good workout for about a week now.
http://www.sonnettech.com/support/kb/kb.php?cat=338&expand=&action=a3#a3
It all seems pretty good. The bug they introduced in version 2.2.0 is fixed (noted here last year - as well as their re-post of earlier drivers after that until they fixed the 2.2.0 issues), and they now have 64-bit support. I've been running my (Early 2009) Mac Pro in 64-bit kernel mode without any problems. (Initially - but see his later comments below on problems seen later) I can't say I've seen any noticeable change in performance so far, but at least it seems pretty stable. Then again, I'm not using much in the way of 3rd-party drivers - just the Sonnet driver (v2.2.1), and the DroboPro iSCSI initiator (v1.6.7).

Anyway, just thought I'd pass this along in case anybody else out there has been waiting for Sonnet to release 64-bit support for the E4P.

(Update: From a later mail (Feb 20th):)
Tempo E4P v2.2.1 drivers cause Mac Pro (Early 2009) to hang
Sigh. It turns out that there are still some serious issues with the Tempo E4P drivers for Snow Leopard on the Mac Pro (Early 2009).

I've been running with the drivers in 64-bit mode for a while now, and have been having problems more and more frequently (probably mainly due the fact that I put some extra drives on the E4P, so it is working harder).
(are the problems seen with 32bit SL boot as well as 64bit?-Mike)
Yes, I get the same buggy behavior on 32bit and 64bit SL. The 2.1.8 drivers work flawlessly on 32bit.
(I think he means v2.1.9 drivers - they were reposted last fall after many had problems w/v2.2.0. However v2.1.9 is no longer on their drivers page.)

The symptoms are simple: either all the disks hanging off the E4P lock up, or worse, all external disks lock up (even a DroboPro connected with iSCSI). Trying a regular restart doesn't work, as the machine hangs indefinitely, so the only solution is a hard shutdown (holding in the power button) and restart.

I did a quick web search, and it looks like other people are having similar problems (e.g., Lloyd Chambers). My problem is not related to sleep issues - my Mac Pro never sleeps, and it has happened both while the machine is idle, and (far far worse) in the middle of a major batch job (which totally ruined my day!). I've emailed Sonnet, but my advice to your readers is to stick with version 2.1.9 of the drivers for now (unfortunately, it also means they have to stay running the 32-bit kernel as well).

Unfortunately, Sonnet have removed the download links for the older drivers (no longer on the Sonnet drivers page), so if you install 2.2.1 you won't be able to back out if you haven't kept a copy of the older drivers...

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