The Mactell XB-Pro G3 300 is a tower-style Mac clone designed for users who demanded high performance in a familiar ATX chassis. Based on the Tsunami architecture and modeled after the SuperMac S900, this clone featured a 300 MHz PowerPC 750 (G3) processor card and shipped with 32 MB of RAM, upgradable to over 1 GB. Storage came via 2.1 or 4.3 GB SCSI hard drives, making it a strong performer in graphics and workstation environments.
This system stood out for its upgrade flexibility, including dual-processor support via ASPD, and expansion via six PCI slots. The included IX-Micro Twin Turbo video card with 8 MB VRAM offered accelerated 2D graphics performance, suitable for multimedia and design users of the era.
Mactell XB-Pro G3 300 – Technical Specifications
| Component | Details |
|---|---|
| Model Name | Mactell XB-Pro G3 300 |
| Architecture | Tsunami |
| Form Factor | PC Tower (ATX) |
| Processor Type | PowerPC 750 (G3) |
| Processor Speed | 300 MHz |
| System Bus Speed | 50 MHz |
| Backside Bus Speed | 300 MHz |
| Level 1 Cache | 64 KB |
| Level 2, 3 Cache | 512 KB (backside), 1 MB |
| FPU | Integrated |
| ROM Size | 4 MB |
| Data Path | 64-bit |
| RAM Type | 70 ns 168-pin DIMM |
| Standard RAM | 32 MB (plus 16 MB onboard) |
| Maximum RAM | 1040 MB |
| RAM Slots | 8 |
| Hard Drive | 2.1 GB or 4.3 GB SCSI-II |
| CD-ROM | 24X |
| Floppy Drive | 1.44 MB (manual) |
| Video Card | IX-Micro Twin Turbo, 8 MB VRAM |
| Maximum VRAM | 8 MB |
| Expansion Slots | 6 PCI |
| Expansion Bays | 1 × 5.25″, 2 × 3.5″ (external) |
| Ethernet | AAUI, 10Base-T (10/100 optional via E100 card) |
| Modem | Not included |
| Battery | 3.6V Lithium |
| Built-in Display | None |
| Dimensions (HxWxD) | 17.25 x 7.0 x 17.5 inches |
| Average Weight | 28 lbs |
| Original Price | $5,000 USD |
| Mac OS Compatibility | 7.5.3 to 9.0 (officially up to 8.1) |
Expandable Clone with SuperMac Roots
What set the Mactell XB-Pro G3 300 apart was its heritage—it borrowed design philosophy from the SuperMac S900 series and extended it with G3 performance. It supported ASPD processor swap and P-series secondary CPU cards, making it one of the most customizable PowerPC clone towers available at the time.
Ideal for professionals and enthusiasts, the system provided classic Mac OS performance in a flexible, industry-standard form factor—long after Apple shut down Mac clone licensing.
