Dual Monitor Support On Mac G4


I've been running a dual monitor setup on my "Digital Audio" G4 tower for some time now. It's got an ATI Radeon 9800 Pro w/ 128MB of SDRAM installed.

My questions is this: It appears that the video card's memory is being split equally between both monitors, devoting 64MB to each one. I'm a graphic designer, and use a wide range of graphics programs to work with large files, and I feel like this may actually be slowing down these types of processes. Is this true? Am I actually putting a 64MB limit on these processes because I have two monitors connected to this card? Would it give me a boost to install an ATI 9700 PCI 128MB card to run the second monitor, giving both monitors 128MB dedicated memory, or am I totally reading this wrong and the current card doesn't actually cap itself to 64MB for processes on each monitor?

Thanks in advance!

Jeff Nicholas


U.S.D.A. Prime
Yes, your video RAM is split equally between the two monitors -- both get 64MB.

Whether or not a full 128MB to one, single monitor will help depends on what you do. I doubt PhotoShop will run much faster (I don't think PhotoShop filters and effects are run through the video hardware, but redraws and screen effects may speed up), but if you do 3D rendering or anything like that it may help. Games may see a performance boost as well, although it won't be mind-blowing, it may be perceivable.

AFAIK, there is no ATi Radeo 9700 PCI Mac-specific card. You can choose from the ATi Radeon 7000 PCI 32MB card or the ATi Radeon 9200 PCI 128MB card -- I believe the 7000 is discontinued, so your only option may be the 9200.