Poor Graphic Performance On Left Cinema Display of Pair

pheidius:

Thanks.  Yeah, got those infamous converter boxes on there .  That whole concept of power and signals all-in-one was a nice idea originally but turned out to be a big techno blunder on Apple's part.  Despite having them in the chain think it was only once over the years that I ever encountered a bum one.  We have a computer room where the MacPro sits isolated from the edit suite for sound reasons.  Enabling that distance required a couple Gefen extension cables which have worked fine.  My first effort to troubleshoot this was to do some swapping of the various elements (I have a new ADC-DVI converter on hand as a backup).  Didn't reveal a weakness in the chain.  Yesterday I saw a post on the 8800 GT where someone complained of essentially the same problem in a single monitor setup and was advised to ensure they were connected to the DVI connector closest to the motherboard.  That's currently my setup, where the main display (which is working smoothly) is running off that connector.  So then I decided to swap the entire signal chain right at the videocard and the problem followed the port, seemingly reinforcing that it's related to the videocard or OS.  I'm pretty sure I had this situation for a brief period a while back but can't recall what I did, so I don't think the repair guys missed anything.  I may have been prepping for a reinstall of the OS at the time anyway and the fresh install took care of it in the process.  I hate the fact that driver control typically is absent from the Mac environment, but I will follow your suggestion and check out that tool.  I did do a couple switches of main secondary and flipped on mirroring once, but perhaps could do a bunch more of that in sequence to see if it 'updates'.  Appreciate all of your recommendations.

Have switch Rez loaded, but to be honest am not sure what to tweak.  Other than the basics concerning gfx cards it's not a subject I know in depth as my work typically only requires stock settings and I'm not a gamer.  Guess I need to read through the documentation. Yes, I was trying to find out how to determine if QE was actually enabled.  However, as my inital question noted System Profiler was indicating the second display didn't support QE.  Wasn't sure why one monitor would be and one wouldn't.  Didn't seem right for a fairly recent gfx card.  I'll check the link.  No, this is an 8800GT that came installed in the Mac Pro.  Actually been a bit problematic before this as After Effects CS4 has some issue with it, but I'm sure that will be worked out in time.  I can come up with two DVI LCDs for testing if need be.  The resolution has always been matched.  Think we use the max for those displays at 1680x1050.  Prior to discovering this problem, though, I was investigating a way to drive a 3rd display, a Panasonic plasma, though a DVI-HMDI connection using a TripleHead2Go or a splitter from Gefen but that may end up being a problem because of mismatched resolutions.  Anyway, that's another story.  I'll keep you posted.

pheidius:

After playing with the Quartz Extreme code in the Terminal window I realized I was, in part, doing what that handy app, Quartz Extreme Check, made a much easier task of.  When you run it it throws up a nice little dialog right smack in the middle of the screen.  So it appears to be working, the question is how to control whether it functions on both screens...assuming my issue is related to QE.  Will bring over those DVI displays later, just to get all the technology up to a more contemporary level and see if that impacts it, but I need to wait for the person using the workstation the displays are set up on to go home.

Sorry, I still need to get Quartz Debug going and see what that tells me.

OK, yes QE not running on the left display is the issue.  Ran the wonderful Frame Rate gauge, which indicated that no matter how much I moved a window around on the left the rate never went above 10 fps, whereas it was upwards of 50 on the right (main).  When I disabled QE in Debug the right display acts exactly as the left has.  Hmmm, so how do I get it functioning on both.  Will report back after I see whether the DVI displays fare batter.

Newer DVI Cinema Displays perform no different.  Read the post of someone with a previous gen Mac Pro who was playing with the Expansion Slot utility and made a change in the utiliztion of lanes that enabled QE on both displays after it stopped working on the second.  We have the Early 2008 model so that utility no longer applies, but it got me thinking if something isn't disabled or missing from the system config then it must be 'interfering' or taking away resources in such a way as to prevent QE from performing on #2 display...

Have to resume the hunt tomorrow.  Enough for one day.

Interesting.  Will do.

HELP!  Not sure how I did it, must have cleared something with OnyX that I shouldn't have, but QE Debug now has the "Enable QE" menu option greyed out, meaning it thinks the graphics card is not QE capable. Now I've got 2 molasses screens.  Using the Terminal command noted in the page you linked me to the code I'm getting back says QE is enabled, but QE debug and actual performance confirm otherwise.  Thought I might rectify things by zapping the PRAM, but that didn't correct it.  How do I get OS X to redetect/reinitialize the graphics card?  As much as I hate Windows a lot of the time at least it's very easy to uninstall a device, update drivers, etc.  Sorry, the limitations of my knowledge regarding the 'deep' innerworkings of the Mac is showing itself.  Fortunately we don't have a job on the system now, but I do need to correct this problem very soon.  Thanks again.

Ok, QE selectability has returned and interestingly the menu entry for Quartz2D Extreme now replaced with QuartzGL.  Guess the applet was updated.  Yes, turning off Beam Splitter does accelerate performance nicely.  There must be a way to permanently disable this.  Back to my orginal situation.  troubleshooting continues.

Yes there is a way to disable it if you google it. I never did it because he terminal commands were too long.defaults write /Library/Preferences/com.apple.windowserver Compositor -dict deferredUpdates 0   you can try this but I thought it didn't live past reboot. K this page looks better http://www.macosxhints.com/article.php?story=20050622224239730

Update:  Figured I was wasting too much time trying to figure out the source of this.  If I couldn't turn up the answer in a reasonable amount of time my normal procedure would be to clone my backup copy of the boot drive (made with Carbon Copy Cloner or SuperDuper) to create a 'fresh install' and update any key preferences files from the old drive.  I recently re-created the system wheh we went to Final Cut Studio 2 but waited a week or two after it had been used to make the clone.  Problem is, because the left monitor was out for repair and we were operating in single screen mode I didn't realize the QE issue existed at that time and it became part of the clone as well.  So my backup was useless.  

This past Thursday I created a fresh install of the OS on a FW drive with only alatest updates applied.  Profiler reported QE supported on both displays and acceleration also enabled on both.  Figured I was at the point of doing a fresh install of everything anyway so I could also have an uncontaminated clone, so I decided to experiment and copy some files over from the working install to the problem one.  Didn't do many files, but I thought maybe replacing the GeForce driver files in the Extensions folder might help.  In the process of this I overwrote the GeForce.kext.  While this created an error (can't load Extension) it did eliminate the problem on the jerkiness while dragging on the left display.  Of course, the system now reported QE not supported on either display and acceleration was completely disabled (although the QE Debug frame gauge still reported about 60 while dragging, there were artifacts (tearing, etc.) when moving windows).  

Guess I could have worked at fixing the kext at that point but the system was free and I had resolved to do a clean install, so I cloned what I had just done on the FW drive and continued from there.  I didn't mind doing the install in this case due to some other things I wanted to see left off this time.

I'm not quite done with the install.  Most of the 'heavy' apps have been installed and QE is working as it should on both displays.  Still need to add After Effects, some plug-is for that a couple other things.  Assuming nothing there creates the problem, we'll be on the lookout for any changes or correspond to the reappearance of the problem (and I'll have a clean clone for recovery).  

So if I have any nes insights I'll try to put them here even as an addendum.

phiedius:  Thanks for your assistance and enlightening me on some useful apps, tweaks, etc.  Technically, I guess I have to make this comment the solution but I'll give you the points for your help.

glad it worked out.

Hello. I just now discovered the actual solution to my problem and it's reflected in my final comment at 8:24PM.  I'd like the question to accurately indicate the solution (I had previously selected my 12:08PM comment and was awaiting approval) but I would still like all the points awarded to pheidius for his/her help along the way.  Can this be done?  Thanks for your assistance.

- mrpierce2