Cubase 8 with HD Native - Word Clock Issue

Hello everybody,

Im having a bit of a problem using my HD Native I/O with Cubase 8.0, hope somebody can help me out there.

I usually use my HD with PT 11 and do most of my recording there, but lately i have been getting quite a bit of work that requires extensive programming with samples so I also use Cubase 8.5 for this. Last year I decided to ditch my Apogee interface in hopes that the HD would cover both PT and Cubase, but the avid core manager seems to be giving me quite a bit of grief, I use Cubase rewired to Ableton Live and load all my samples in Vienna Ensemble Pro outside the host, so here is my problem:

After a couple of hours working in Cubase, with a lot of samples loaded (about 28 Gb) all of a sudden the sound starts cracking up and getting glitches. This usually happens when I load any new VST instrument or create a send, but sometimes it just happens out of nowhere (and the cpu graph on the activity monitor shows a suden spike in the cpu usage). Now my question is: Is this behavior caused due to the fact that the HD I/O was made just for PT and its use with any other DAW through the avid core manager is not supported 100% or is it a question of something like Word Clock?, do i need to get SYNC or do you think the best solution would be to just get a dedicated interface for Cubase? like Symphony. Or is it a question of actually upgrading to PT 12?

This is driving me crazy because i have to restart Cubase 30 times a day and im loosing so much time!!! Hope somebody can help.

Thanks

Juan

Mac Pro (Mid 2010)
2 x 2.66 GHz 6-Core Intel Xeon
36 GB RAM
PT 11.3.1
Cubase 8.0.30

I just experienced this with a 12 core yesterday .
The studio runs PT with an HD 192 and sync

I prefer cubase 8.5

Assigning I/O was slower than usual. Refreshing was required. Reopening past connection tabs etc.

The HD card does not talk to cubase quickly. Selecting events was sluggish. Starts and stops of playback and record delayed almost 2 seconds after pressing the space bar. Then after about 2 hours glitches appeared as well.

So sync is not helping