bare feats real world speed tests

Can The "Dual Head" DX-Max AGP Graphics Card Run Two Displays As Fast As One?

April 13th, 2001
rob ART morgan, Bare Feats mad scientist

Do you want two displays but hate to use two slots? Don't you wish you had two AGP slots to run two fast graphics cards? Well ProMax has the solution. They call it the "Dual Head" card or DH-Max. It sounded great but I had to wonder if it can handle the happenings on two displays as fast as two cards can handle two displays. And how does it compare to other graphics cards in terms of performance? Let's take a look...



Performance Analysis

For 2D, it's not quite as fast as the GeForce2 or Radeon. Three-D needs work. They are promising OpenGL support real soon now.

Surprisingly, there was no speed penalty for running two displays simultaneously. The times shown on the graphs above were identical for either display. That's due to the design which uses a unique 256-bit DualBus combined with 128-bit memory bus.

However, if you can afford to use one of your PCI slots, the Radeon PCI is faster and comes with a DVI, VGA, and S-Video out.

It occurs to me that the DH-Max would make an interesting upgrade for a Power Cube owner who has no PCI slots but wants to run two displays. Be aware that it only has VGA connectors so it won't work if you have the newer Apple flat panel or CRT's.

Don't count on playing Quake or Unreal or other 3D hardware accelerated games with the DH-Max. Quake 3 Arena returns an OpenGL error and quits. The RAVE version of Unreal Tournament gave a black screen when I tried to set up a game. In defense of the DH-Max, it is designed for video production, not for gamers. In fact, it comes with an adapter that lets you connect one of the ports to an NTSC or PAL studio monitor.


Where To Buy

Order the DH-Max direct from ProMax for $299. (The original manufacturer is Matrox who makes a similar card for Windows PC's. They fully endorse this product.)

If you want to run 2 ADC displays, take a look at Gefen's solution.


Test Notes

Test system was an Apple Power Macintosh Dual G4/533 with 512M of RAM running Mac OS 9.1

Test cards included:

Four tests were performed:

  • Photoshop (6.0) Zoomed Scroll -- I zoom in to 400% on a 27MB document and scroll from top to bottom, measuring the time with a stopwatch.
  • AppleWorks (6.0) 250 Page Scroll -- I use a stopwatch to see how long it takes to scroll through a 250 page document.
  • CineBench OpenGL Shading -- I use the Shading test to compare the speed at which the card can handle dynamic shading and model "fly by." CineBench uses a rating system instead of frames per second.
  • Walker 3D Corridor Spin -- This demo application was created by Dair Grant of LightWork Design. I use the sample 3D model called Corridor. I spin around from one position. The frame rate can vary from 8 to 80 frames per second, depending on how many polygons are having to be drawn. I'm most interested in the frame rate at most complex part of the model. (Walker 3D was removed from their site.)

© 2001 Rob Art Morgan.

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