NuBus Video Cards

Radius PrecisionColor 24XP

The Radius PrecisionColor 24XP card is a 12" NuBus card compatible with 680x0- and PowerPC-based Macs running up to Mac OS 8.5.1. It may be compatible with higher versions of the Mac OS, but no information for Mac OS 8.6 is available at this time, and it's doubtful that the card is compatible with Mac OS 9.

Hands On: Chris Lawson

PrecisionColor 24XP tested in a Mac IIcx running System 7.1.0 and the QuickColor control panel from RadiusWare 3.3 installed.

The following video benchmarks were obtained at 640 x 480 resolution using Speedometer 4.02:

computer            1-bit   4-bit   8-bit  16-bit
IIcx, "Toby"        0.252     n/a   0.248     n/a
IIcx, PC 24XP, off  0.280   0.265   0.243   0.214
IIcx, PC 24XP, on   0.290   0.307   0.341   0.406
IIcx, 8•24 GC, on   0.421     n/a   0.422     n/a

The "Toby" card is Apple's unaccelerated Macintosh II Video Card; it wasn't tested in 4-bit mode. The PrecisionColor 24XP was tested with acceleration off and on. Performance was significantly improved with acceleration enabled: 3.5% faster at 1-bit, 16% faster at 4-bit, 40% faster at 8-bit, and a very impressive 90% faster at 16-bit.

The Apple 8•24GC accelerated video card is shown for comparison. I wasn't tested on the 4-bit setting, doesn't support 16-bit video, and won't work in 24-bit mode on the IIcx. On the tests we did run, it easily outperforms the PrecisionColor 24XP.

Worth noting: It might just be my card (ROM version 2.0), but this card does not do millions of colors at 640 x 480 in the IIcx - it has a bunch of horizontal lines and wrong colors on the screen and is nearly illegible. It works fine at thousands and below except for 2-bit, which is not an option. The card really shines at thousands of colors but is still only good for running a second monitor in a Quadra, since the onboard video in Quadras is pretty fast on its own.

One of the nicest features of this card is the Radius PowerSaver control panel - it works fine with my Apple High-Resolution RGB monitor, turning it off after the specified period of time. I don't know if it actually cuts power consumption - I don't have a way to test it - but it apparently turns the CRT off.


The card provides standard QuickDraw acceleration. The Radius PrecisionColor 24XP supports the following resolutions in 24-bit color:


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