The bigger brother of the PX5 in ATX form factor is suffering from the same problem as its sibling, it is quite touchy about the SDRAM that’s used with it. Unlike the VX chipset predecessor of this board (IT5V) and unlike the TX boards form Shuttle and AOpen, it wouldn’t run stable with the Corsair SDRAM I’m using by default. This is not a very serious problem as long as you are using only 66 MHz bus speed, but 75 and 83 MHz will give you a lot of headaches until you find the proper SDRAM to go with it. I succeeded to run this board at these bus speeds with Toshiba SDRAM eventually.
This board is also using the TX chipset, it comes with the usual Abit SoftMenu and unlike the latest revisions of the IT5H it still includes the ’turbo frequency’ for 66 MHz. The performance is a little better than the performance of the PX5, but you could expect more form a TX board, especially in comparison to the ’old’ HX board IT5H. From the stability point of view do I prefer the IT5H, or if it has to be SDRAM and Ultra-DMA, the AOpen TX boards or the Shuttle HOT-565. From the convenience point of view however, it’s certainly the nicest TX board.
Coming with 4 PCI, 4 ISA, 4 SIMM and 3 DIMM slots, it supports all Socket 7 CPUs, including the M2 and the 3.2 V for the K6 233, you can use each type of RAM, cacheable area 64 MB, no ECC support, Ultra-DMA support, switching voltage regulator.
This board is still one of the fastest Socket 7 boards, especially at the usual bus speeds and the latest revision 1.5 supports 75 and 83 MHz as well. This revision is out now. It is a HX chipset board, so it can do ECC if you fancy that. Since revision 1.2 it is now also including a large tag RAM, which enables 512 MB of cacheable area. As all the recent Abit boards it comes with the SoftMenu feature (=jumperless design) and offers you the ’turbo frequency’ for ’non-overclockers’.
I recommend this board especially in the latest revision (1.5 and up) to everyone who wants to have a Socket 7 board that supports almost everything except the UltraDMA feature. It’s a very good performer, it’s extremely convenient due to its jumperless design and it can handle 512 MB RAM as well as 83 MHz bus speed.It’s actually one of the fastest boards for a K6 233 under Windows NT. The 83 MHz performance is somewhat lower than of a TX board, due to the missing SDRAM support, since with EDO you have to reduce the RAM timing for 83 MHz.
The IT5H comes with 4 PCI, 4 ISA, 4 SIMM and 2 DIMM slots, it supports all Socket 7 CPUs, including the M2 and the 3.2 V for the AMD K6 233, you can use FPM and EDO RAM of up to 512 MB, which is all cached by the L2 cache, it supports ECC, but it does not support SDRAM and Ultra-DMA. It until revision 1.6 is out it comes with a passive voltage regulator, but it is cooled very well and gets less hot than all the other passive voltage regulators I know.
The PX5 is Abit’s new Intel TX chipset board in Baby-AT form factor. It comes now with a BIOS that supports 83 MHz bus speed and it includes of course the SoftMenu feature, which saves you from fiddling around with jumpers. It seems that either the new 83 MHz BIOS or the my test board itself is not adjusted perfectly, because the 83 MHz were pretty unstable so that I had to reduce the SDRAM timing, which is unusual for TX boards. The board is also slower than with the previous 75 MHz BIOS, so that the performance I measured isn’t really too fast. Abit promised me a new board and a new BIOS revision and I will test it again as soon as I received it. Other TX boards as the AOpen AP5T or the Shuttle HOT-565 are faster at 83 MHz, they run at the fastest settings.
This Baby-AT board comes with 4 PCI, 4 ISA, 2 SIMM and 2 DIMM slots, supports all Socket 7 CPUs inclusive the M2 and 3.2 V for the AMD K6 233. All RAM types can be used, up to 256 MB are allowed, but don’t forget the TX chipset 64 MB cacheability pitfall, which will cost you 5% of performance in case you want to use more than 64 MB RAM. This board supports Ultra-DMA and no ECC. The PX5 comes with a switching voltage regulator.
AOpen AP5T(-3) (Baby-AT) And AX5T(-3) (ATX)
These two new TX chipset boards in Baby AT (AP5T) or ATX (AX5T) form factor are good performers. They support SDRAM (two DIMM sockets) and if you are into highest performance, you can benefit of their 75 and even 83 MHz bus speed support. The TX chipset offers the new Ultra DMA or ATA-33 EIDE specification for disk transfer rates up to 33 MB/s.
These boards underlie the limitations of the TX chipset, which means no ECC support, RAM only cacheable up to 64 MB. Hence you should forget about using more than 64 MB RAM, because it will do a performance impact of about 5% and you will not be able to use any RAM error correction.
Both boards are running extremely stable at high bus speeds as 75 and 83 MHz and you can take the full advantage of it in case you are using SDRAM. At these bus speeds these boards are faster than their competitors with HX chipset from Asus and Abit. The direct competitor of the AP5T (Baby-AT form factor) is the Shuttle HOT-565. It’s identically fast and has the same features except a better (switching) voltage regulator.
The AP5T comes with 4 PCI, 3 ISA, 4 SIMM and 2 DIMM slots, and the AX5T has one ISA slot more. Both support all current Socket 7 CPUs and from rev.3 also the 3.2 V for the AMD K6 233. All RAM types can be used, 64 MB cacheable, 256 MB max. Support of Ultra-DMA, no ECC. Both boards have passive voltage regulators and they get very hot. The AP5T was one of the boards that failed running NT due to a bad power supply.
Asus P/I-P55T2P4 Rev. 3 And Higher
The good ’old’ T2P4 has still got it’s charm. It was the first board to support 83 MHz bus speed and it offers the HX chipset features like ECC support and up to 512 MB cacheable RAM. It’s lacking SDRAM support, but since it runs fine with high quality EDO RAM, why bothering ? It also doesn’t have ATA-33 support, but currently there isn’t any Ultra DMA HDD available which would take advantage of 33 MB/s transfer speed.
Since BIOS revision 2.02, this board recognizes and initializes the K6 properly now and from board rev. 3.2 it supports the 3.2 V of the K6 233 as well. The new BIOS has improved the T2P4’s performance, so that it is still doing very well in the field with all these ’youngsters’.
The T2P4 doesn’t have any advantage over the Abit IT5H anymore, it’s a little slower and less convenient. Consider this in case you have to pay the same price for both or even less for the Abit.
Features : 4 PCI, 3 ISA, 4 SIMM slots, supporting all current Socket 7 CPUs, revision 3.2 supports 3.2 V for AMD K6 233 as well, ECC support, no SDRAM or Ultra-DMA support. 512 MB cacheable in case you are using COAST module with proper tag RAM or you got tag RAM chip for empty socket on board. The T2P4 has got a switching voltage regulator since the very beginning.
This board is some kind of special fellow. It doesn’t bother having SIMM sockets anymore, which is probably the reason why it’s usually shipped with one Asus 32 MB SDRAM DIMM. There is a version (TX97-E) that will allow you to use your old 72 pin SIMM EDO or FPM, but I haven’t received that one for testing, neither the ATX versions. It comes with a nice gimmick, which enables you to monitor the CPU and board temperature, the CPU fan function (that’s why it comes with its own heatsink/fan) and the board’s voltages. You can either check these values in the BIOS setup menu under ’Power management’ or via the Intel LDCM software from Win95, NT and over the network, that comes with the board on a CD.
The performance of the TX97 is very good, especially since its latest BIOS release 1.04. It’s one of the fastest Socket 7 boards available. However there’s one big let down, it does not support 83 MHz bus speed and rumors say that this is due to Asus close relationship to Intel. My personal opinion is to prefer an board that’s a little slower but offering 83 MHz support and I don’t really understand why Asus went off the 83 MHz idea, which was first introduced by themselves.
The TX97 comes with 4 PCI, 4 ISA, 3 DIMM slots, supporting all current Socket 7 CPUs, for the AMD K6 233 you can jumper 3.1 V, it doesn’t have ECC support, neither does it cache more than 64 MB of RAM, due to the TX chipset. It supports SDRAM, Ultra-DMA and FPM or EDO in case you can get them in form of DIMMs. It has a switching voltage regulator.
The Shuttle TX board is performance wise quite close to the AOpen TX boards and it also has almost the same features. It supports 83 MHz bus speed and hence it can run really fast with a K6 or Pentium at 250 MHz. It supports the K6 233 voltage of 3.2 V and these are supplied by a switching voltage regulator, that doesn’t get touched by bad power supplies too much at all. The decision between this board and the AOpen ones is certainly not easy, especially since the quality of both boards is also almost identical. I think that the switching power supply is one reason to go for this board, but as far as I know will AOpen put these on their next revisions as well.
Features : 4 PCI, 3 ISA, 2 DIMM, 4 SIMM sockets, supporting all current Socket 7 CPUs, supporting 3.2 V, no ECC support, cacheable area 64 MB, SDRAM and Ultra-DMA support, switching voltage regulator.
Tyan Titan Turbo S1570
Tyan’s TX board sticks to the usual standards of this US company, which offer maximum expandability. 5 PCI and 4 ISA slots are as high as you can go, 6 SIMM slots as addition to the 2 DIMM slots fulfill the needs of almost everyone. The performance at 66 MHz bus speed puts it in the league of the fastest Socket 7 boards. However there are also some let-downs. Tyan takes customer complaints extremely seriously and is still very afraid of RMAs due to unreliable functions under higher bus speeds such as 75 and 83 MHz - you obviously can’t really blame them for that. To avoid any incidents it doesn’t give you any chance to use these bus speeds at all. This is the reason why Tyan boards are not the right ones for overclocking types, but just right for high performance users that wouldn’t overclock in the first place. I spoke to several people at Tyan, including the COO and CEO and this policy might change pretty soon. The other temporary problem is the K6 support. If you run the K6 you must take care that you are using the very latest BIOS, because the BIOS my board came with wouldn’t enable the K6’s ’write allocate’ feature. If you are using the tools supplied by AMD, you won’t have a problem with that. Tyan is working hard on a new revision of this board, including the high bus speeds and eventually the proper voltage for the K6 233 of 3.2 V as well as a switching voltage regulator. My board here can only go up to 2.9 V for the K6 and it’s the second board that failed to run NT due to my test bad power supply. Let’s hope that this new revision will be out soon, so that all overclockers can take advantage of this extremely expandable board.
Features : 5 PCI, 4 ISA, 6 SIMM, 2 DIMM sockets, K6 supported with latest BIOS, no support of 3.2 V yet, no ECC support, cacheable area 64 MB, SDRAM and Ultra-DMA support, passive voltage regulator that is sensitive to bad power supplies.
Tyan Turbo ATX S1572
There is not much to say about the S1572. It’s the ATX brother of the above S1570 and its performance as well as its features are almost equal to the S1570. The main difference is that it comes with one PCI slot less, due to the ATX specifications.
Tyan Tomcat III 1563D
The Tomcat III dual CPU HX chipset board is out now for quite a while and eventually it found its way into my test lab. Again it’s a typical Tyan board, coming with a wealth of expandability features like 5 ISA, 4 PCI slots, 8 SIMM sockets and two Sockets 7, since this is a dual CPU board. The performance of this board is good, a little slower than the Abit HX, but faster than the Asus HX board. As mentioned above it suffers from Tyans fear of angry customers and hence it doesn’t support 75 or 83 MHz bus speed. It comes with a passive power supply, that isn’t strong enough to feed two Pentium MMX 200 CPUs (you only can use two P5 MMX 166 or two P5 Classic 200 CPUs), but it offers with 3.0 V a voltage that’s close enough to the 3.2 V a K6 233 needs. The next revision will most likely include the high bus speeds as well as a switching power supply with 3.2 V support. I personally can’t wait for that, because otherwise there’s no Socket 7 board out that could compete with its expandability features.
Features : 5 ISA, 4 PCI, 8 SIMM sockets, K6 support with latest BIOS, no 3.2 V support, ECC support, cacheable area 512 MB, no SDRAM or Ultra-DMA support, passive voltage regulator