The FS50 motherboard
The heart of the SS50 is Shuttle's tour-de-force of miniaturization, the FS50 motherboard. Built to conform to the Flex ATX spec, the SS50 packs nearly everything you'd want in a modern PC onto a 254mm by 185mm board. Let me drop the spec list on you, then I'll cover the highlights.

CPU support Socket 478-based Pentium 4 CPUs with 100MHz front-side bus
Form factor Flex ATX
Chipset SiS 650 (SiS 650 North Bridge, SiS 961 South Bridge)
Interconnect SiS MuTIOL (533MB/s)
PCI slots 2 32-bit 33MHz
AGP slots None
AMR/CNR slots None
Memory 2 184-pin DIMM sockets for up to 2GB of PC1600/PC2100 DDR SDRAM
Storage I/O Floppy disk
2 channels ATA/100
Ports 1 PS/2 keyboard, 1 PS/2 mouse,
2 serial, 4 USB (2 front, 2 rear), 3 IEEE 1394 (1 front, 2 rear), 1 RJ45 Ethernet, 1 DB15 VGA out, 1 S-Video out

2 line out/front out (1 front, 1 rear), 1 line in/rear out, 1 bass/center out, 1 mic in (front) for C-Media 8738 audio
BIOS Award 6.0
Bus speeds 100MHz-165MHz in 1MHz increments
Monitoring Voltage, fan status, and temperature monitoring

The FS50's advancements over the FV24 are legion. This time around, Shuttle has chosen an SiS chipset, the 650, which offers GeForce2 MX-class graphics built right into the north bridge chip. This graphics core is similar to the SiS 315, which we reviewed here. The SiS 315 is a full DirectX 7 GPU with a T&L engine and support for environmental bump mapping.

Like most integrated video solutions, the SiS 650 GPU has to share memory bandwidth with the processor, but in this case, there's 2.1GB/s of memory bandwidth available, courtesy of the FS50's 266MHz DDR SDRAM. No, the FS50's fill rate isn't going to lend itself to lots of high-res gaming, but the graphics ought to be fast enough to run most current games in lower resolutions.

The SiS 650 chipset, of course, also provides support for Pentium 4 processors, which means the board offers a 400MHz front-side bus and insanely high processor clock speeds. To keep things pumping, the SiS 650 also uses a 533MB/s link between its north and south bridge chips. (For the curious, SiS claims its MuTIOL interconnect "features a bi-directional 16 bit data bus operating in 4 x 66MHz.")


The SiS 961 south bridge chip

Shuttle has augmented the SiS chipset with a number of task-specific custom chips. Almost as if to prove a point about their prowess, Shuttle's engineers have added chips rather than use the built-in functions of the SiS 961 south bridge, like sound and Ethernet networking. The FS50 uses C-Media's 8738 chip to generate six-channel positional audio on par with a SoundBlaster Live! card, and a RealTek chip handles 10/100 Ethernet connectivity. An SiS 301 provides TV encoding for the S-Video out port, and a Lucent FW323 brings Firewire capabilities. There's also an ITE chip to handle legacy I/O like serial ports and PS/2 ports.


C-Media's ultra-popular 8738 chip provides 6-channels of audio goodness

There are, in short, loads of chips on this teeny little motherboard, and by virtue of them, the FS50 offers features, connectivity, and I/O on par with a typical full-size ATX system outfitted with a couple of PCI expansion cards.


At rear, the SS50 bristles with ports—plus two PCI slots