[Success]... mostly. Haswell + 10.9 + GTX670

[nxent]

Intel 3.4 Ghz Haswell
Gigabyte UDH5 MOBO
Gigabyte GTX670 graphics
16 GB Corsair 1600mhz ram (2x8)
seagate 4TB storage drive
240gb boot drive
OS 10.9
Multibeast 6 - don't recall exact settings, but using mac-pro 3,1
LG DVD/BD optical drive
corsair 500r tower

++++++++++++++++++++++++++
Finally got rid of the random freezes by putting the ram modules in the proper slots.
A couple of issues remain though:

1) Can't play movies from itunes without a hard freeze
2) Apple TV has trouble accessing itunes library. Oddly enough, I have no trouble pushing itunes media from the copm TO the Apple TV (As opposed to pulling FROM the Apple TV...).
3) Optical drive seems to hang the finder whenever a disc is left in the drive. When the disc is first inserted, all works well. But if I leave the disc in there for a while (long enough for the drive to sleep, perhaps?) the Finder hangs.

 

[NexusEclipse]

Did you have any luck resolving this? I have exactly the same problem (purchased cloud videos in itunes hard crash my system). Oddly, if my Apple TV is selected as the output, itunes can play the videos with no problem. This leads me to think that the integrated graphics driver (and maybe its interaction with the discrete card) is driving the problem. I have not really pushed trying to fix it since my real Mac Pro handles my iTunes library but now that there is someone with my exact same problem, I feel more vested.

My system is as follows:
Gigabyte Z87MX-DH3
i7-4770k
Haswell certified Seasonic PSU
16 gb Crucial Low Profile 1.35v Ram (installed side by side)
Sapphire AMD 7870
512 M4 SSD - Mac
128 OCZ SSD Vertex 3 - Windows bootcamp (pulled from Mac Pro)
500 Seagate HD - for data
Dual Screen both over Displayport but one connected to the integrated and one to the AMD card
Multibeast 6 (going to upgrade to 6.1 to see if that helps)
IO Gear recommended bluetooth (no drivers)
TD-LINK recommended WiFi adapter (no drivers)

My testing plan:
1. Upgrade to Multibeast 6.1
2. Connect only one display to the discrete graphics and see if the issue persists
3. See if it is actually hard crashing and not just freezing the display (I think I had a download running one time and it appeared to have finished in the background). Also if I try to do display mirroring on the apple tv I also only get a frozen image (could be related).

Intel 3.4 Ghz Haswell
Gigabyte UDH5 MOBO
Gigabyte GTX670 graphics
16 GB Corsair 1600mhz ram (2x8)
seagate 4TB storage drive
240gb boot drive
OS 10.9
Multibeast 6 - don't recall exact settings, but using mac-pro 3,1
LG DVD/BD optical drive
corsair 500r tower

++++++++++++++++++++++++++
Finally got rid of the random freezes by putting the ram modules in the proper slots.
A couple of issues remain though:

1) Can't play movies from itunes without a hard freeze
2) Apple TV has trouble accessing itunes library. Oddly enough, I have no trouble pushing itunes media from the copm TO the Apple TV (As opposed to pulling FROM the Apple TV...).
3) Optical drive seems to hang the finder whenever a disc is left in the drive. When the disc is first inserted, all works well. But if I leave the disc in there for a while (long enough for the drive to sleep, perhaps?) the Finder hangs.

 

[nxent]

not sure if you resolved this or not, but i fixed the freezing during itunes playback by deleting the integrated graphics kexts (i don't recall which ones, specifically, but there's a thread someone on tonymac about it). that's the good news. bad news is, the itunes videos (HDCP videos bought from the itunes store) still won't play. apparently no one's figured out a work around yet...

as for the apple tv - it works maybe about 50% of the time. rebooting it seems to help. i'm beginning to think it's an issue with the apple tv itself..?

another issue i'm having is this: I can only leave my hack running for maybe 5 or 6 days before it starts to destabilize... Mail, Safari, iTunes.. and eventually the Finder start crashing. but once i reboot, everything is fine. my older mac comps (power mac g5, mbp, imac) can run for months at a time - is this an issue common to mac hacks?