provided by: 
Originally published at Internet.com
* Specifications * CPU Soft Menu * Documentation * Performance * Advantages/Disadvantages * Overall Report * Contacting ABIT Computer Corp. ----------------------------------------------------------------- Important Addendum
All of the known bugs, such as the battery overvoltage problem and the incompatibility with some ATX power supplies, have been fixed in rev. 2.22. Don't let it's previous problems effect your opinion of the AX5. ABIT has indeed fixed all of the problems, and they no longer exist.
And a quick note about using SDRAM!
If you happen to have any difficulty getting SDRAM to work in the AX5, or if you haven't bought SDRAM and you want to make sure you buy the right kind, ABIT says that 10NS Toshiba SDRAM works "rock solid". I used a 32MB DIMM made by "Siemans" for the review.
Specifications: ----------------------------------------------------------------- CPU:
* Uses ZIF CPU Socket 7 * Three voltage regulator/cooling plate sets for a more stable CPU operating environment. * Supports Intel Pentium CPUs: 75MHz to 250MHz+ and P55C MMX CPUs * Supports all AMD sixth generation AMD-K5 and K6 CPUs * Supports all Cyrix sixth generation 6x86 CPUs * Reserved circuitry supports future sixth generation CPUs * Supports 75MHz and 83MHz bus speeds.
Chipset
* Intel 430TX chipset * Supports standard version PCI 2.1
L2 Cache Memory
* 256K or 512K cache memory (Pipelined Burst)
System DRAM
* Four 72-pin SIMM sockets: support FP and EDO DRAM * Three 168-pin DIMM sockets: support FP, EDO and Synchronous DRAM (SDRAM) * DIMM sockets use PC modules (3.3V Unbuffered DRAM) * Up to 256MB memory configuration possible * Allows you to mix EDO SIMMs with SDRAM DIMM(s) -- (The AX5 that I am using to type this has 2 16MB 60ns EDO SIMMs and 1 32MB SDRAM DIMM co-existing without any problems)
BIOS
* AWARD BIOS * Supports Plug-and-Play (PnP) * Supports Advanced Configuration Power Interface (ACPI) * Supports Desktop Management Interface (DMI)
Multi I/O
* Two Universal Serial Bus (USB) ports * Four fast IDE channels (PIO mode 0-4, Ultra "DMA/33" and Bus Master) * One EPP/ECP parallel port and two 16550 serial ports * Two floppy disk drive connectors (FDD) (360K, 720K, 1.2M, 1.44M, and 2.88M)
Other features
* Standard ATX architecture dimensions * Four ISA bus slots and four PCI bus slots * Supports 3-MODE for a special Japanese floppy disk drive * Supports two bootable hard disks--able to run two different operating system
CPU Soft Menu (TM) ----------------------------------------------------------------- The CPU Soft Menu is a menu within the BIOS Setup that allows you to setup the speed and voltage of the CPU, as well as the bus speed and multiplier factor. Because the CPU is setup completely through the Soft Menu, there is no need for jumpers or DIP switches.
Soft Menu's outstanding features:
* The ability to specify the the CPU speed and have the external clock and multiplier settings automatically set, * The ability to manually specify the external clock settings. The supported speeds are: 50MHz, 55MHz, 60MHz, 66MHz, 75MHz and 83MHz. * The ability to manually specify the clock multiplier settings: 1.5x, 2.0x, 2.5x, 3.0x, and 3.5x, * The ability to manually specify the voltage from single or dual. Single processors such as the Pentium P54C, the Cyrix 6x86, and the AMD-K5, use only one voltage. However, future processors such as the P55C MMX Pentium, the Cyrix 6xx86L, and the M2, require dual voltages - one for the internal processing of the CPU and one for external processing.
The single voltage options are: 3.38v, 3.52v, and 3.6v. The Dual, Core Plane Voltage options are: 2.50v, 2.70v, 2.80v, 2.93v, and the I/O Plane voltage options are: 3.30v, 3.38v, 3.52v.
One additional feature of the CPU Soft Menu is the Turbo Frequency Setting. This setting allows you to speed up the external clock by 2.5%, thereby increasing the CPU speed as well. Take note however, the turbo frequency feature is only an option at a bus speed of 66MHz. The feature is designed to be used as an important tool for test units to verify CPU stability, and it is reccomended that it not be used for normal operation. The AX5 performed flawlessly with the feature enabled though (it also performed flawlessly with the external clock speed set to 75MHz and a CPU speed of 225MHz, so I doubt 2.5% extra on top of 66MHz is going to faze it ;), but it is a bit of a speed increase for those who don't want to overclock.
A new feature to ABIT's CPU Soft Menu is an option called "Speed Error Hold." When enabled, this function prevents the user from operating the CPU at a higher speed than is intended. (if you put a P55C-200MHz CPU in the AX5 and try to run it at 250MHz, and Speed Error Hold is enabled, the BIOS won't let the system boot and will give you an error such as, "CPU settings have changed..." When disabled -- overclock till your heart's content!
Documentation ----------------------------------------------------------------- All of the ABIT manuals are virtually identical. Therefore, the following text is basically a duplicate of the other ABIT board reviews. The manual for the AX5 is detailed, accurate, and very complete. There are explanations for all of the external connectors, all of the CPU Soft Menu settings, and almost all of the BIOS settings. It is by far one of the most complete manuals I have seen. By comparison, most manuals give pictures of what settings are present in the BIOS Setup, and some even say what the options are for each setting, but few offer explanations on what the settings do.
The only shortcoming of the manual's explanations is on the DRAM memory settings. Instead of detailing what each of the settings does, the manual simply states:
"... If you do not understand this very well, don't make any changes. Our BIOS is able to autodetect the characteristics of your DRAM and to choose the best settings."
There are a ton of diagrams in the manuals that include information such as:
For Pentiums: What multiplier factor and external clock settings should be used with a certain speed CPU. The diagrams even go so far as to list the CPU model number to be certain that the voltages/clock settings are set correctly for each model.
For Cyrix and AMD:
Tables that describe the different parts of the CPU model number to help you decifer the codes into different things such as Internal Clock speed, processor name, P-Ratings, Package Type, Case Temperature and Operating Voltage.
All of the tables are extremely detailed and contain very useful information.
Performance
The performance of the AX5 was measured using the benchmarks shown below for various CPUs, with a system setup of:
ABIT AX5 Motherboard Matrox Millenium 4MB WRAM (@1024x768 - 16bit color) One (1) 32MB SDRAM DIMM Western Digital Caviar 22100 2.1GB HD
Windows Benchmarks
Processor CPUMark 16 CPUMark 32 Norton SI Winstone 97 Pentium 200MHz MMX
Author: Scott Wainner
Read article at Internet.com site