Bad VST performance for Cubase 6.5.4 on Mac pro 2,1

Hello Cubase 6 forum,

I just bought a Mac Pro 2,1 with 8 cores of 3 Ghz and 8 gigs of Ram and I’m pretty disappointed with how Cubase performs on it. My last computer was a 5 year old macbook pro Dual core 2.3 Ghz with 3 gigs of ram and the VST performance on my mac pro is not that much better. The strange thing is that when I monitor my CPU performance with activity monitor it tells me that my processors are mostly idle even Cubase is running so hot that I’m getting audio glitches.
I’ve had a look around various different forums and there does seem to be a lot of people saying that Cubase isn’t very good at hyper threading on macs but surely it can’t be that bad. Currently, Cubase is only using a fraction of my computers capabilities. Has anyone got any suggestions about how I might improve Cubase’s multicore CPU usage.

Here is list of the software I’m using. It’s very short as I like to keep things as simple as possible.

MacOS 10.6.8(Plus whatever software that comes bundled with it)
Cubase 6.5.4
Various Waves bundles and plugins
Sonnox reverb
2C Audio Aether
All of the D16 plugins
All of the Audio Damage Plugins

first cubase does not utilize hyperthreading. second your machine is a version 2,1 which is an older model and Im not sure what has changed in the architecture recently but w Mac Pro we are at least on version 5,1 intel hardware now

You can test your project by deselecting multi processing in the vst audio device panel. Some pluggins that do not properly support multiprocessors you may see an improvent in performance. for example i had some older waves version I was running on C4 that i just upgraded from waveshell 6 to version 9 and the new versions are noticeably more efficient. Also 2c Audio 's reverbs are heavy duty computationally.

FWIW i am just moving into 64 bit mode and that is helping me - i just inquired recently at a post (link below) and while it that info was more specific to windows there are a few posts that should shed some light on the problem.

Have a look through this thread and check my post at the end