Hey Trips, I just wanted to thank you for your post as I am experiencing the exact same scenario as you, almost down to the letter. And like you I am at my wits end. Two solid weeks of digging with no results. Praying someone can help you with your issue because it sounds like it may fix mine as well.
First off, I don't want to hijack this thread, just wanted to add my info for troubleshooting perspective. Hopefully some of the work I have done will give you some insight into what you are dealing with yourself. If anyone is reading this, please address Trips' scenario.
The reason I think my info may be helpful is that I am using an older mobo yet experiencing the same issues, and as you deduced, I believe my issue is also a global problem as opposed to specific to any one device or piece of software. Also, my last ditch solution was going to be to build a new machine almost exactly like the one you have built (I'm very jealous by the way! Nice rig! :) But seeing you are having these issues gives me hope that a solution will give me a few years of work out of this old rig of mine.
The core of the issue seems to show itself most clearly in the following scenerio - I plugin my Focusrite, set it as default audio (ASIO), get sounds out of the speakers (from an mp3 or internet), everything seems fine, until I open Maschine or Pro Tools. Only then does Task Manager show CPU spikes at regular intervals. This is without any audio playing in either Maschine or PT11. When audio plays, the baseline CPU usage increases only slightly and the spikes remain. This happens with Pro Tools 11 open (no session open, nothing playing) and with Maschine open (again nothing playing.) Close Maschine or Pro Tools and the spikes disappear, turn off the Focusrite and the spikes disappear. This happens at any buffer setting although the CPU usage baseline and peak height change with different buffer settings but only slightly. This tells me it is not specific to Maschine or Pro Tools (as it happens with both open separately), or the buffer settings.
As with you, the culprits seem to be USBPORT.SYS, ATAPORT.SYS, HAL.DLL (among others in a minor way) all causing system interrupts. This info comes from running DPCLAT, LATMON, and xperf.
Troubleshooting done so far:
1. Disabled Ethernet, Floppy Drive, Firewire, other audio engines, DVD drive, all to no avail.
2. Disconnected my RAID drives and rebooted to see if anything changed. No joy.
3. Disconnected my Focusrite and set my Eleven Rack as the default audio, no change. (This tells me also that it is not specific to the Focusrite or Eleven Rack)
4. Updated BIOS, updated Ethernet, Graphics drivers, and Chipset with no change. Also updated USB drivers (I had to manually go in and update the USB drivers as they were all stuck on version 6.1.7601.18328 with a date of 6/21/2006. I have been able to update my Intel(R) ICH10 Family USB Enhanced Host Controller to version 126.96.36.1995 with a date of 2/25/2008 but my USB Root Hub remains at the older version/date and I can't seem to find a way to update these.)
5. Physically removed my graphics card and switched to internal graphics. No change.
6. Reinstalled all Maschine drivers/software, reinstalled Pro Tools. No change.
7. Ran System File Checker - came back clean.
8. Ran a Memory Test - came back clean.
9. Disabled Microsoft Security Essentials - no change.
10. Plugged my front panel USB hub into a different socket on the mobo, plugged the Focusrite and Eleven Rack into different USB ports, etc - no change.
Here are my basic specs: (just switched my rig to a new SSD with a fresh install of Win7x64 SP1 hoping to get some more life out of this rig)
OS: Win 7x64 SP1 (Fresh install 3 weeks ago on a brand new SSD)
CPU: Intel Core2 Duo CPU E8400 @ 3.00GHz (2C 3GHz, 6MB L2)
MOBO: GigaByte EG45M-UD2H
RAM: 4x G.Skill F2-6400CL5-2GBPQ 2GB DIMM DDR2 PC2-6400U DDR2-800 (Total 8GB)
OS Drive: Samsung SSD 840 EVO 250GB (250GB, SATA600, SSD)
DATA Drives: 2x Seagate ST3640323AS (1.3TB, RAID0/SATA300, SCSI-4, 3.5", 7200rpm)
VIDEO: Integrated Intel Graphics
1) Focusrite Scarlett 18i20 Interface (USB2)
2) Avid Eleven Rack (USB2)
1)Maschine Studio (USB2)
Network Adapter : Realtek PCIe GBE Family Controller (Ethernet, 100Mbps)
FireWire/1394 Controller 1 : Gigabyte TSB43AB23 1394a-2000 OHCI PHY/link-layer Controller
SMBus/i2c Controller 1 : Intel ICH SMBus
Audio Software: Pro Tools 11
So I am curious Trips, when you have Maschine or your DAW open and your Audio Interface on and connected but not playing anything, do you see these intermittent, regular CPU spikes too? Mine are timed about 5 or 6 seconds apart and go from 0-1% to 60-80% CPU usage, and last for about 2-3 seconds. Oddly enough, I can play an mp3 or wav file in Windows Media Player or a hidef video with audio in chrome (through the Focusrite) and I don't see any spikes or weird behavior. Very strange.
I find it interesting that you are using Firewire and I am using USB with similar issues. We do both use an SSD and a separate RAID array. Not sure what that means though...
Anyway, I hope this helps you in some way with perhaps some more perspective on your issues. And again, thanks for taking the time to post. I eagerly await a solution or it's off to the insane asylum for me :)
And to anyone with thoughts or solutions, thank you in advance for your time and any help you can provide.