The Mactell XB-Pro G3 300 is a high-performance Macintosh clone from 1998, engineered on the Tsunami architecture and rooted in the SuperMac S900 platform. Powered by a 300 MHz PowerPC 750 (G3) processor card, this clone delivers enterprise-grade performance in a standard ATX tower enclosure. Its modular layout made it one of the most upgradeable systems of its time.
Standard configurations included 32 MB of RAM, SCSI-II hard drives (2.1 or 4.3 GB), and an 8 MB IX-Micro Twin Turbo video card. The tower supported dual processors through Mactell’s ASPD (Advanced Second Processor Daughtercard) technology, making it popular among graphics professionals and Mac power users.
Mactell XB-Pro G3 300 – Technical Specifications
| Component | Details |
|---|---|
| Model Name | Mactell XB-Pro G3 300 |
| Architecture | Tsunami (based on SuperMac S900) |
| Form Factor | ATX Tower (PC style) |
| Processor Type | PowerPC 750 (G3) |
| Processor Speed | 300 MHz |
| System Bus Speed | 50 MHz |
| Backside Bus Speed | 300 MHz |
| FPU | Integrated (PowerPC 750) |
| Level 1 Cache | 64 KB |
| Level 2 Cache | 512 KB (backside), 1 MB (L3 optional) |
| ROM Size | 4 MB |
| Data Path | 64-bit |
| RAM Type | 70 ns 168-pin DIMM |
| Standard RAM | 32 MB |
| Maximum RAM | 1040 MB |
| Motherboard RAM | 16 MB onboard |
| RAM Slots | 8 |
| Hard Drive Options | 2.1 GB or 4.3 GB SCSI-II |
| CD-ROM | 24X |
| Floppy Drive | 1.44 MB (manual) |
| Video Card | IX-Micro Twin Turbo with 8 MB VRAM |
| Maximum VRAM | 8 MB |
| Expansion Slots | 6 PCI |
| Expansion Bays | 1 × 5.25″, 2 × 3.5″ (all external) |
| Ethernet | AAUI, 10Base-T (10/100 optional with 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 (Apple officially supported up to 8.1) |
Flexible Power for the Mac Clone Era
The Mactell XB-Pro G3 300 stands out for its balanced design — high-speed PowerPC performance, dual-processor potential, and wide compatibility with Mac OS and expansion cards. Thanks to its S900 heritage, this Mac clone offered more than standard Apple towers, appealing to enthusiasts who valued flexibility, performance, and long-term upgrade options.
