Dual Monitors Reduce Performance?

Since the System Profiler shows video card memory split equally if two monitors are connected, does that mean there is a reduced performance for the features in Motion which rely on video board RAM?

Is it best to only connect one display in order to get the most out of the video board, OR, is the memory allocated to the respective displays simply not a factor in Motion's use of VRMA, resulting in no drawback to connecting two monitors?

...Tom



G4 1.25 DP MDD, 2GB, Radeon 9700 Pro Mac, 23" Apple Display with ADC and 20" Apple Multiscan VGA. Motion hasn't arrived yet.

My copy of Motion seems to run well on my system with a similar setup. Quicksliver 2002 dual 1.0 Ghz - 1.5 GB Ram - ATI Radeon 9800 Pro Mac Edition video card.

22" Cinema Display (ADC) and Sony G500 21" CRT (VGA)

Guys, after reading an article by David Saraceno at Kenstone.net i assumed that running Motion off of my 9600 Pro with two 17" LCD monitors connected to it would result in a sluggish performance of the app. Never got a chance to test that theory though, since i had an old ATI 7000 lying about, i just split the monitors off and so far i've no real complaints. Frankly, i'm surprised we hadn't seen this thread sooner.

-abehjha

Both Creative Cow and Apple Motion Discussions have mentioned this subject, but nothing close to a definitive answer.

Anyone from the Apple Motion team care to step in on this?

It would seem reasonable to assume having two displays connected to the same board would cut Motion's performance in half for those specific features that are videoboard-dependent.

Barefeats has a good rundown on CPU/graphic card combinations (although no comparision with G4 MDD with Radeon 9800), but also doesn't mention the possible dual display issue.

[www.barefeats.com]

Motion and the 9700 should arrive today, so I'll see what kind of tests I can run over the next few days to get some idea about this. Could be that with a marginal rig like mine that overall it just doesn't matter whether two displays are connected or not.

...Tom

Hi Guys,

Running two monitors off one card does split the V-RAM and this will cut Motions on screen performance.

--ken

So, I guess the question would then be given the relative speed of a particular G4 or G5, its system memory and the video card with its VRAM, just how much would a dual monitor set up drag down the VRAM-specific features and the overall performance of Motion?

May not worth the effort to try and quantify this, as you either need or want to run two monitors or you don't, and if you do, there's going to be something of a performance hit if using a single card. Just have to see how it works out.

...Tom

Tom,

I can tell you that the 64 meg video card that ships with the new G5s will enable Motion to run but after adding just a few elements the playback frame rate will drop to 4 or 5 frames per second. Very choppy, not good.

I have run with 128 megs of V-RAM and the speed goes up to about 17 fps. Only the 256 card comes close to real 'real time', but add enough to your prroject and even the 256 will bog down.

My 2 cents.

--ken