There has been a lot of discussion about getting MC3.0 (PC) to work with Geforce cards on these forums (thanks to all the people who contributed their experiences with this.)  This information is spread across a few different threads, some of which are rather long.  I therefore started this thread in order to concisely list the various possible fixes in the top post of a single thread.  I would also like to ask if there are other fixes that I have not heard of yet, and get opinions and feedback on these fixes from other users.

I want to be clear that I owe ALL of the thanks to other Avid users who were able to figure out these fixes, and then took the time to share their findings here.  I am merely "gathering" the information from others that have done ALL the work.  I have not had the opportunity to try these fixes myself yet, so I welcome any feedback and/or corrections.  I simply started taking some notes on this subject, and figured that this info could be helpful to others, so I'm posting it here.

Quadro Soft-Mod.  The first fix that I heard about was the Rivatuner Quadro Soft-Mod fix.  This involves using a program called Rivatuner to "modify" the Geforce card via software so that the system "thinks" the Geforce card is a Quadro.  This fix is limited to only certain Geforce variations, so some Geforce cards cannot (at least not yet) be soft modded.  More information about this can be found here:  http://www.techarp.com/showarticle.aspx?artno=539&pgno=1.  This fix has been reported to work with both XP and Vista.

Force OpenGL 1.5.  The second fix was to once again utilize Rivatuner to apply a setting called "Force OpenGL 1.5."  This setting does not require a reboot, so it can be easily switched on just when Avid is used, and then switched off again.  So far, I have not yet heard of any side effects in Avid from forcing the older OpenGL version, so I'd be curious to hear if anyone has ever seen any limitations from using this fix -- i.e. does anyone know if Avid utilizes any "post-version-1.5" OpenGL features?  This fix has been reported to work with both XP and Vista.

Turn OFF "Threaded Optimization."  The third fix is to open the Nvidia Control Panel and go to "Manage 3D Settings > Threaded optimization" and switch it to "Off" (the default is "Auto.")  Once again, I have not not read of any side effects from this fix, but I'm always curious to hear feedback from people that have tried it.  This fix offers the advantage of negating the need for a third party application (Rivatuner), but I don't know if there are any performance advantages or disadvantages to this fix compared to the other fixes.  If Avid is unaffected by this change, than this would be the "easiest" solution.

Note that the Nvidia Control Panel offers the capability to set program-specific settings rather than making a change "global" (see the two different tabs), so it might work to add "Avid" to the list of programs, and then make this change so that it ONLY effected Avid.  I have not heard of anyone trying this yet, so I don't know if this would work.  If it did not, the change could be made globally whenever Avid was used, and then switched back to "Auto" for other programs.

One thing that I still need clarification on with the "threaded optimization" fix is if it works for XP as well as Vista.  So far, the posts that talk about successfully using this fix either list Vista 64bit as their OS, or don't list the OS at all.  I have not found a post that mentions using this thread that ALSO mentions using XP.  I do know that this setting shows up on XP systems, but it would be nice to have a confirmation from somebody using this fix with XP.

I welcome feedback from people that have used one or more of these fixes, including corrections or additions to what I've said.  If anyone knows of another fix that I have not yet heard of, please share it here.

Thanks again to the Avid forum community for all the terrific work in addressing this issue,

Larry

 Program specific setting in Nvidia control panel works with avid.   Threaded Opt off only during Avid start.

01/02/08 update:  I re-installed the 177.79 beta into vista64.  Now MC3 starts without hanging on ACPL -- no adjustment in the nvidia control panel required.

lalittle:

Turn OFF "Threaded Optimization."  The third fix is to open the Nvidia Control Panel and go to "Manage 3D Settings > Threaded optimization" and switch it to "Off" (the default is "Auto.")  Once again, I have not not read of any side effects from this fix, but I'm always curious to hear feedback from people that have tried it.  This fix offers the advantage of negating the need for a third party application (Rivatuner), but I don't know if there are any performance advantages or disadvantages to this fix compared to the other fixes.  If Avid is unaffected by this change, than this would be the "easiest" solution.

Note that the Nvidia Control Panel offers the capability to set program-specific settings rather than making a change "global" (see the two different tabs), so it might work to add "Avid" to the list of programs, and then make this change so that it ONLY effected Avid.  I have not heard of anyone trying this yet, so I don't know if this would work.  If it did not, the change could be made globally whenever Avid was used, and then switched back to "Auto" for other programs.

In the version of the nVidia control panel that I use, there are two tabs, one for global settings and one for program specific settings.  The program specific one is the one that automatically pops up when the control panel starts so you actually make it seem more complex then it really is.  You just open the nVidia control panel, select Avid Media Composer as the program to optimize on the top left of the screen, and then go down and click "threaded optimization" to off.  No other programs should be affected and it's simple as pie.  Doing this, I quickly got my GeForce GT9800GTX to play nice with Avid and didn't have to mess with any soft-modding or tuners.  Especially where soft-modding is concerned, I don't think convincing your video card to think it's a different card is going to be a good idea as far as stability is concerned. 

As far as "side-effects," I really couldn't say since I don't know how fast MC 3.0 would have been running if I hadn't used this setting (it wouldn't launch without out).  What I can tell you is that everything has been blazing fast on my new rig (I mostly edit 720p) and full screen playback works like a charm.

 The "turn off thread optimization" does not work for me.  I'm on XP with 175.19 drivers with a 8800 GTS 320Mb.

The switch to V1.5 openGL does not work either.

The only thing so far for me is emulate a Quadro 4600. 

 I'm on Vista 64 and I can't find where in rivatuner you can emulate a geforce into quadro...
What should I do?

Glans:

 I'm on Vista 64 and I can't find where in rivatuner you can emulate a geforce into quadro...
What should I do?

 Did you try the other fixes first?  Based on my reading, the quadro soft-mod is the most difficult of the 3 fixes listed.  I'd only try it if the other fixes didn't work.

As far as the question of how to use the soft-mod goes, did you check the link listed in the top post of this thread (ie. http://www.techarp.com/showarticle.aspx?artno=539&pgno=1)?

Larry

 It's been a long time since I posted here. After reading a lot of threads I decided to go out and purchase a 8800GT to see what all the fuss was about. Running Vista 64 bit, Installed the card updated the drivers to 175.19 Avid opened up without a problem. Then installed the latest driver 177.89 (may be beta, http://downloads.guru3d.com/) once again Avid opens without issues, plays back fine with full screen playback. Then I figured I would do what I have been doing for years with GeForce cards, install the Quadro driver that Avid recommends, in this case it's 169.47. Driver installs with Geforce 8800 GT and Avid opens up without issues. No soft mod, no force open gl, no threaded optimization needed. Like I said, I have been using Quadro drivers for years with Geforce cards. Next step I took was to download the latest Quadro driver 169.96, to my surprise this driver would not install to the Geforce 8800GT. Maybe Nvidia has wised up. Anyway, with the latest Nvidia Geforce drivers for your 8800 GT series card you should not have any issues or have to jump through hoops just to get Avid to open and play nice. Then again, I'm using Vista 64bit cannot say what other operating systems this works for.

gvs:

Anyway, with the latest Nvidia Geforce drivers for your 8800 GT series card you should not have any issues or have to jump through hoops just to get Avid to open and play nice. Then again, I'm using Vista 64bit cannot say what other operating systems this works for.

I seem to remember seeing some posts saying that these fixes were not needed with 64bit Vista, so this may indeed have been an important difference in your case.

What I'm most curious about now is whether or not 3.0.5 changed the behavior of Geforce cards with MC at all.

Larry