NuBus Video Cards

Radius Thunder IV GX

Physical Specs and Compatibility

The Radius Thunder IV GX series of cards are 7" NuBus cards compatible with 680x0- and PowerPC-based Macs running up to Mac OS 9.1. The card is known to be compatible with Sonnet and Newer Tech G3 upgrades.

We have had reports of incompatibility with Virtual Memory in Mac OS 8.1 through 9.0.4. They may be compatible with higher versions of the Mac OS.

Hands On: Chris Lawson

This baby is flying even in this IIcx. Same benching platform as the others; IIcx with 32 MB RAM, System 7.1, and Speedometer 4.02.

computer             1-bit  2-bit  4-bit  8-bit 16-bit
IIcx, "Toby"         0.252                0.248
IIcx, ROPS 24XLi     0.245                0.242
IIcx, Thunder 24     0.296  0.283  0.276  0.398
IIcx, Thunder IV GX  0.289   n/a   0.261  0.462  0.538

This card is killer for 16-bit acceleration. It feels faster than any of the SuperMac cards I've tested, and the Speedo numbers bear this out.

With acceleration off, this card is pretty pedestrian:

computer             1-bit  2-bit  4-bit  8-bit 16-bit
IIcx, Thunder IV GX  0.290    n/a  0.261  0.241  0.213

Now to find a NuBus-based Power Mac to see if Radius's claim of "up to 20x the speed of the 8100's built-in video" is true :)

Acceleration/Resolution/Color Support

The cards have four onboard AT&T 3210 DSPs (digital signal processors) running at 66 MHz for Photoshop acceleration and provide standard QuickDraw acceleration as well. All Thunder IV cards support the following resolution/color combinations, except as noted:

  • 640 x 480 up to 24-bit
  • 832 x 624 up to 24-bit
  • 1024 x 768 (at 75Hz) up to 24-bit
  • 1152 x 870 up to 24-bit
  • 1152 x 882 up to 24-bit
  • 1280 x 1024 up to 24-bit (1360 only)
  • 1360x1024 up to 8-bit (1152 only)
  • 1360x1024 up to 24-bit (1360, 1600)
  • 1600x1200 up to 8-bit (1152, 1360)
  • 1600x1200 up to 24-bit (1600 only)

The 1360 and 1600 support 1360x1024 in 24-bit color, while the 1152 supports this resolution in 8-bit color only. The 1600 also supports 1600x1200 in 24-bit color, while the 1360 and 1152 support this resolution in 8-bit color only.


  • Links to Radius and SuperMac software on Gamba's site.
  • QuickColor 3.3 (part of RadiusWare 3.3) works fine under any Mac OS up to and including Mac OS 9.1.
  • Dynamic Desktop crashes the Mac OS at startup when installed on Mac OS 8.6 or higher. SwitchRes (shareware) works to change resolutions instead.

Other Notes

  • DSPs (digital signal processors) are incompatible with Mac OS versions over 7.5.5 according to Radius. QuickDraw acceleration remains compatible.
  • The Thunder IV GX 1600 is compatible with Mac OS versions up to 8.5.
  • The Thunder IV GX 1360 is compatible with Mac OS versions up to 8.6.
  • These cards are compatible with G3/G4 upgrades.
  • The Thunder IV GX 1600 is compatible with Apple or Daystar PowerPC accelerator cards, but the PhotoEngine software is not. PhotoEngine software will be disabled and should be removed.
  • While these cards regularly appear on eBay, they are very highly sought after and, as such, command a premium price. Don't expect to get any of these for much less than US$100 - and expect to pay near $200 for the Thunder IV GX 1600.

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