The Tyan Trinity 400
S1854 Via Apollo Pro133A mainboard

Monday, March 13, 2000


Due to a lack of available time, I was - until now - unable to examine the much-celebrated Tyan Trinity 400 S1854. Now, though, I have the chance to do just that. The S1854 implements the VIA Apollo Pro133A chipset, and benefits consequently from support of PC133 memory, 4X AGP, and ATA66 drives. One of the main peculiarities of the S1854 lies in its support for two different processor connectors. Unlike most of the mainboards, the S1854 sports not only a Slot 1 connector, but also a Socket 370. The S1854 is thus able to make use of the full range of Intel PII, PIII, and Coppermines for Slot 1, and for those in the new FC-PGA format. What we have then is an extremely versatile board, in terms of its support for processors. All that said, it can be considered that the development of the S1854 by Tyan came as a result of the long production lag in both RAMBUS and Intel 820 chipset.

The features

The S1854's expansion possibilities are provided by its 6 PCI slots, no ISA slots, and single AGP port.

Note that a version sporting an ISA expansion slot is also available.

In terms of memory, the S1854 sports 3 168-pin DIMM sockets which can support upto 768MB of memory.

One other note is the inclusion of an integrated PCI sound card which is based on the Creative Labs ES1373.

Configuration of the S1854 is accomplished through a set of BIOS options and jumpers. The sole function of these jumpers is to set the processor's clock multiplier; a fairly inconsequential detail considering Intel processor's have been ignoring the user-chosen clock multiplier for years. In the BIOS, the "Chipset Features Setup" menu contains a function for adjusting the main bus frequency between to any of the following speeds: 66Mhz, 75Mhz, 83Mhz, 95Mhz, 100Mhz, 112Mhz, 117Mhz, 124Mhz, 133Mhz, 138Mhz, 140Mhz, and 150Mhz with a clock multiplier of between 3X, and 8X in steps of .5X.

Finally, like many other boards, the S1854 permits the memory bus to be set to a value 33Mhz above or below that of the FSB.

Among the many BIOS options, two functions are worth of mention here. One is the AGP Driving Control function, which permits one to assure compatibility with AGP cards, and the other is the CPU IOQ Size function, which determines the size of the In-Order-Queue - which can be set from 1 or 4, with 1 being the default. When the IOQ is set to 4, a noticeable jump in performance is achieved. Of course, the system can also become unstable under these conditions. Thus, only your own test will tell if stability while using an IOQ of 4 is satisfying for your needs. The IOQ also happens to be a function that's found with the Abit BF6. If you remember that board, recall that the In-Order-Queue, when set to 1, totally deactivated the processor's pipelining.


Seeing as this board does not possess jumpers allowing the system bus to be forced into a given frequency (66Mhz, 100Mhz, 133Mhz) as is the case with several other boards, it is therefore impossible to push the system to 133Mhz when using a processor meant to operate on a 100Mhz bus. Normally, there is such a set of jumpers that allow the system to be forced into a setting of 66Mhz, 100Mhz, or 133Mhz, as desired, but unfortunately that is not the case here. So, if you absolutely insist on using a 133Mhz bus with an FC-PGA processor, it will be necessary to use an FC-PGA compatible Socket 370-to-Slot 1 adaptor, and set the adaptor to 133Mhz.

Another thing to note is that in such a case (as it often happen with Overclocking tests), it might becomes impossible to reboot the system. However, when this happens, the S1854 possess a function that will allow it to ignore the last series of changes that were made to the BIOS. So, if in Overclocking the S1854, you find yourself unable to boot, then, power off the system, wait 10 second, press the "Insert" key, power on the system and hold the "insert" key pressed until the CPU frequency is displayed on the monitor. At that point, unpress the "insert" key and press the "Del" key, and make your changes to the BIOS.

One final note, is that the onboard soundcard cannot be deactivated, as no jumper is provided for that purpose. It is thus necessary to deactivate it from the Windows devices manager if you really wish to do so, with all the headaches that may entail. Since the integrated sound card is included as an option only, I'd advise anyone who wishes to use an external sound card later not to buy the version of this motherboard with the onboard soundcard.

Next: additional features.