[malawar]

Introduction:
I'm running this session and facing a few problems which I've listed below. I can't figure out if it's a hardware or software issue. I've also listed some of the things I think are causing or resulted in the problem. I've leaning towards it being a software issue since I compared this session to a similar session and and the other session works fine. I hope someone can go over the information I've provided below and maybe help me resolve this or optimize my system better.

Problems:
1) Latency when on record-arm or input-monitor even with low buffer.
2) MIDI region first notes on bar disappear
3) While looping a section, I hear the last notes of the previous bar; although they're not in the selection. I've also

What I think is causing the problems:
1) Audio is recalled from back up copy on my external drive rather than being saved in the "clips" and recalled from the internal hard drive.
2) Group-moved everything to an earlier spot in the editing window (including meter changes and markers)
3) Too many instruments/plugins (although the other session has more or less the same)

System Specs:
Please see signature for details.

Session Info:
48 kHz
24 bit
System Delay: 7757 samples (2319 in other session I compared to)
BWF (.WAV)

Playback Engine (I've tried all the different combinations here):
128 samples
1 GB Cache

System Usage:
CPU approximately 40% total on both sessions
Disk 0%
Disk Cache 12%
Memory 15%
Voices 30/256
HDX Card has quite a few here all over 50%

Failed attempts to resolve the issue:
1) reduce buffer size to 64 samples
2) dedicate thunderbolt bus on mac to HDX card
3) go over the system optimization document on Avid website
4) run all possible plugins on DSP
5) free space on Mac (98GB free from 256)
6) run session on Mac instead of external HD
7) "save copy in" to create a new version of the session

Sorry about the heavy post, I tried to add as many details as I could, I'm still an amateur on Pro Tools and might not understand a lot of the technical aspects of the software.

Looking forward to your responses!

Best,

M