Asus' XP55T2P4 is the ATX version of the famous P55T2P4 AT board. Featuring the Intel i430HX chipset, it can support 512MB of EDO-DRAM, and if the optional TagRAM socket is populated it can cache all of it too. It supports FSB speeds of 50, 55, 60 and 66MHz, but unlike its AT sister, there are no settings for higher speeds due to the ICS9159M PLL not supporting more than two frequency select pins. The boards is shipped with either 256kB of L2 cache and a COAST slot or 512kB and no COAST slot (the latter shown in the photograph).
Split voltage is supported, with voltages down to 2.5V available officially. With multiple jumpers it is possible to obtain lower voltages down to 2.0V (jumper 2.5V, 2.7V, 2.8V and 2.9V for this). Pretty much any So7 CPU is supported on this board, although anything expecting an FSB over 66MHz will run proportionately slower. AMD K6-2+ and K6-3+ CPUs require an unofficial BIOS (linked below) to be correctly recognized.
Max HDD size with official Asus BIOS is 32GB, but the unofficial BIOS patch for K6plus CPUs also increases the HDD limit to 127GB.
On the Rev.3.0 board subpar I.Q. 1000uF 6.3V capacitors were used, which should be checked for bulging, leaking or other failure.
Aside from 4 PCI slots and 3 ISA slots, the board contains an Asus proprietary MediaBus 2.0 slot, which is essentially an extra ISA slot in miniature form in front of the 4th PCI slot. Asus manufacturer a small number of combined VGA/audio and SCSI/audio cards (with ATi Mach64 VGA, Adaptec 2940UW SCSI and Creative SoundBlaster Vibra16C audio). Note that MediaBus 2.0 is not backwards compatible with Mediabus 1.2, so older cards cannot be used.