Although it seems like ATX is taking over the world there are quite a few users who are ATX challenged and refuse to leave their wonderful AT standard behind. Actually, before I bought my Pentium II, I was much like that. Now I have seen the light and will never go back, however for those of you that still aren't convinced that ATX is the way of the future ABIT has made a scaled down version of their excellent AX5 TX board, called the PX5...however, how closely did ABIT model the PX5 after the AX5, is 1 DIMM slot the only thing missing from the PX5? Let's find out...

Motherboard Specifications

Socket Style: Socket 7
Chipset: i82430TX
Cache: 512KB
Form Factor: AT
BUS Speeds: 50 / 55 / 60 / 66 / 68 / 75 / 83 MHz
Clock Multipliers: 2.0x / 2.5x / 3.0x / 3.5x / 4.5x / 5.0x / 5.5x
Voltages Supported: 2.5 / 2.7 / 2.8 / 2.9 / 3.2 / 3.38 / 3.52
RAM Slots: 2 72pin SIMM Slots (EDO/FPM)
2 168pin DIMM Slots (EDO/FPM)
PCI/ISA Slots: 4 PCI Slots
4 ISA Slots (1 Shared / 1 Full Length)
BIOS: AWARD PnP BIOS w/ SoftMenu CPU Setup
PCI EIDE Controller: Super I/O
2 EIDE Channels
1 FDD Channel
2 Serial /1 EPP


The Good

Like the newest revision of the AX5, the PX5 from ABIT is in no way impaired and functions above and beyond the call of duty. When ABIT stated that the PX5 came in a "baby-AT" form factor they weren't exaggerating at all, this is one of the smallest Socket-7 AT boards I have ever come across. That can be a major plus, especially if you are installing it in one of those Full Tower cases with 12 or more bays, so you have more room available for your computer to "breathe", meaning better cooling. Like any other ABIT board, the PX5's major strongpoint doesn't come from its Jumperless SoftMenu CPU Configuration, but from its excellent documentation. ABIT's manuals are some of the best I have ever seen, they contain detailed diagrams, large and bolded headers for important topics, as well as easy to follow how-to instructions. Setting up an ABIT board is beyond simple, with the manual in hand you can cut the motherboard installation and configuration time to under 4 minutes if you really know your way around the system, and have a handy power screwdriver =)

I mentioned before that the PX5 is a scaled down version of the AX5, this is mainly because in order to keep the footprint of the PX5 as small as possible the ABIT engineers had to make a few sacrifices. The main features of the AX5 that got the boot were 2 out of the 4 SIMM slots and one of the 3 DIMM slots. As a result of this, expansion on the PX5 isn't too highly encouraged.

Performance-wise, the PX5 is almost on par with the AX5, scoring a tad bit slower in most tests. After retesting the ABIT AX5 and getting it to work properly at the 83MHz bus speed, I felt like I was on a roll, so I decided to give the PX5 another shot at the gold...the results? Not bad at all...after performing another clean format (I have to admit that after testing the AX5 I didn't perform a clean format and reinstallation of the testing suite as I normally do since I figured the two boards were similar enough), popping in the Megatrends SDRAM yet again and removing some left over drivers I got the board to work much more stable at the higher bus speeds. However did this cure ALL of the problems I experienced with the PX5...?

The Bad

I still am not completely satisfied with the PX5, its performance is not up to par with the ABIT AX5 and the cramped Baby-AT form factor can be difficult to work with, especially if your motherboard tray was designed for use with larger AT boards. Unlike the AX5, I couldn't get the PX5 past 233 with any processor, not even with the Pentium MMX which is a bit of a disappointment. However very few users actually run their 233MHz Pentium MMXs at 290.5MHz so it isn't that great of a problem. The overclocked stability of the PX5 still lags behind that of the AX5 as well as competing boards.


IRQ Usage

  • Allows user to individually set IRQs for each Legacy ISA card

  • Allows user to reserve IRQ/DMA Channels if necessary

  • Auto-detects PnP Cards after HDD Detection


BIOS Settings

Here are my Recommended BIOS Settings for those of you who have been having problems with the IT5H and higher bus speeds. Below are my recommended settings for bus speeds < 66MHz, 75MHz, and 83.3MHz. If you are using Non-EDO RAM, then use the settings the in the 2nd (Non - EDO) column, if you are using EDO RAM with a 50/60/66MHz bus speed use the 3rd (66MHz Setting) column. If you are using EDO RAM with a 75/83.3MHz bus speed use the 4th (75/83MHz Setting) column. Finally, if you are looking for the safest and most stable setting, use the last column.

PX5 Chipset Features Setup

Item Non - EDO 66MHz Setting 75/83MHz Setting Safe Setting
Auto Configuration: Disabled Disabled Disabled Enabled
DRAM Leadoff Timing: 11/7/4 10/6/3 11/7/4 11/7/4
DRAM Read Burst (EDO/FPM): x222/x333 x222/x333 x444/x444 x444/x444
DRAM Write Burst Timing: x222 x222 x444 x444
Fast EDO Lead Off: Disabled Enabled Disabled Disabled
Refresh RAS# Assertion: 4 Clks 4 Clks 5 Clks 5 Clks
Turbo Read Leadoff: Disabled Enabled Disabled Disabled
Refresh RAS# Assertion: 4 Clks 4 Clks 4 Clks 5 Clks
Fast RAS to CAS Delay: 3 2 3 3
DRAM Page Idle Timer: 2 Clks 2 Clks 2 Clks 4 Clks
DRAM Enhanced Paging: Enabled Enabled Enabled Enabled
Fast MA to RAS# Delay: 2 Clks 2 Clks 2 Clks 2 Clks
SDRAM(CAS Lat/RAS-to-CAS): 3/3 2/2 3/3 3/3
SDRAM Speculative Read: Disabled Disabled Disabled Disabled
System BIOS Cacheable: Disabled Disabled Disabled Disabled
Video BIOS Cacheable: Enabled Enabled Enabled Enabled
8 Bit I/O Recovery Time: 2 2 2 3
16 Bit I/O Recovery Time: 3 3 3 4
Memory Hole At 15M-16M: Disabled Disabled Disabled Disabled
PCI 2.1 Compliance: Enabled Enabled Enabled Disabled



Recommended SDRAM

This little addition to my review layout was put in here just so you all can have an idea of what brand of SDRAM I recommend and have tested with the board, just to avoid problems in the future if you decide to purchase the board.

Recommended SDRAM: Advanced Megatrends SDRAM; Corsair SDRAM; SmarTech SDRAM
SDRAM Tested: 2 x 32MB Advanced Megatrends SDRAM DIMMs; 2 x 32MB SmarTech SDRAM DIMMs; 2 x32MB Corsair SDRAM DIMMs

SDRAM to Avoid with this board: pairs of 2 SDRAM DIMMs may cause some problems, not in all cases though. Overall stability is decreased when using a pair of SDRAM DIMMs with the PX5.

Manufacturer: Advanced Megatrends
Purchase Web-Site:

Manufacturer: Corsair Microsystems
Purchase Web-Site:


The Test

In recent times, choosing a motherboard cannot be completely determined by a Winstone score. Now, many boards come within one Winstone point of each other and therefore the need to benchmark boards against each other falls. Therefore you shouldn't base your decision entirely on the benchmarks you see here, but also on the technical features and advantages of this particular board, seeing as that will probably make the greatest difference in your overall experience.

Test Configuration

Processor(s): AMD K6/233 ANR & Intel Pentium MMX 233 & Cyrix 6x86MX-PR2/200
RAM: 2 - 32MB Advanced Megatrends SDRAM 2 - 32MB SmarTech SDRAM 2 - 32MB Corsair SDRAM
Hard Drive(s): Western Digital Caviar AC21600H
Video Card: Matrox Millennium (2MB WRAM)
Busmaster EIDE Drivers: Intel v2.85
Video Card Drivers: MGA Millennium
OS: Windows 95 Service Release 2

Windows 95 Performance of the ABIT PX5

CPU Business Winstone
AMD K6/200 52.5
AMD K6/225 56.6
AMD K6/233 56.1
Cyrix 6x86MX-PR2/166 (150/75) 53.4
Cyrix 6x86MX-PR2/200 (166/66) 56.1
Intel Pentium MMX 200 51.0
Intel Pentium MMX 225 56.4
Intel Pentium MMX 233 56.1

The Performance of the PX5 is almost on par with the AX5, although a tad bit slower in most cases, I'm not exactly sure why. It seems as if ABIT did some work 'underneath the hood' with the PX5, just goes to show you that looks and be deceiving.


The Final Decision

I strongly suggest staying away from this motherboard, unless all the overclocking you wish to perform can be done using the 66 or 68MHz (turbo frequency) bus speed. If you don't plan on overclocking and don't want to get the more advanced ATX version of the PX5 (the AX5) then this is an excellent board. However I wouldn't recommend it too highly for a die hard overclocker, I seriously doubt that you will have the world's best time when using some of the higher bus speeds with this board, it caused me quite a bit of trouble although I seemed to have resolved quite a few of the problems myself.

Comments Locked


View All Comments

Log in

Don't have an account? Sign up now