Hi Jim,
I believe you're already working on this with our front-line Product Support team. The problem is that for your virtual sessions through Citrix, the virtual vga layer is being used, whereas when using RDP directly to the server that does not come in to play. Inventor will detect that virtual layer & default to a lower graphics performance level, since the nvdia GRID cards are not being "seen".
From the diagnostic info which was sent to Product Support you can see the info to confirm this:
For Citrix session:
Graphics Device Information:
Renderer: SW
Manufacturer: (Standard display types)
Chip Type: GRID K2
DAC Type: Integrated RAMDAC
Graphics HW Memory: 3.933 GB
Display Mode: 869770120 x 869770120 (869770120 bit) (869770120 Hz)
Graphics driver file: 6.1.7600.16385
Driver file version: 6.1.7600.16385
Driver Date: 21 June 2006 0:00:00 UTC (Coordinated Universal Time)
Direct3D Graphics Device Information:
Adapter Description: Citrix Systems Inc. Display Driver
Vendor ID string: 0x00000000
Device ID string: 0x00000000
VendorID: 0
DeviceID: 0
SubSystemID: 0
Revision: 0
For RDP:
Graphics Device Information:
Renderer: HAL
Manufacturer: NVIDIA
Chip Type: GRID K2
DAC Type: Integrated RAMDAC
Graphics HW Memory: 3.933 GB
Display Mode: -1048576 x -1048576 (-1048576 bit) (-1048576 Hz)
Graphics driver file: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2um
Driver file version: 9.18.13.4052
Driver Date: 2 July 2014 0:00:00 UTC (Coordinated Universal Time)
Direct3D Graphics Device Information:
Adapter Description: NVIDIA GRID K2
Vendor ID string: 0x000010de
Device ID string: 0x000011bf
VendorID: 10de
DeviceID: 11bf
SubSystemID: 100a10de
Revision: a1
The Vendor ID String & Device ID Strings are used as lookup values by Inventor. The defaults are set in a file "C:\Program Files\Autodesk\Inventor 2015\Configuration\hardwarelibrarydm.xml". From that you can see that the Vendor & Device ID Strings for Citrix (virtual vga) are set to level 10 for each different operating system. If you change that value to 50, Inventor should not defualt to using software graphics anymore for new virtual sessions, but you will still not be using the full nvidia GPU until that virtual graphics layer has been removed for the Citrix sessions.
I don't know the exact sateps to disable that virtual vga layer for the Citrix sessions, but am awaiting further info from our Citrix experts. You may also be able to get the necessary steps from your Citrix/nvidia partner in the meantime.
Thanks,
Chris

Chris Mitchell
PDMS Customer Engagment Team
Autodesk, Inc.