LOSTCIRCUITS

The BIOS for the FS40 is supplied by Phoenix Award and uses the standard yellow on blue interface. Most of the settings are straightforward, that is, everything that concerns the system configuration from the boot sequence to the integrated peripherals and hardware monitoring falls into the "off the shelf" category.

The BIOS does not offer any overclocking settings, but allows adjustments for the different flavors of 100 / 133 MHz FSB CPUs as well as PC1600 / 2100 memory in any combination of the two parameters. Since there are no FSB adjustments and the system is thermally already pushing its envelope it is a wise decision not to add any voltage adjustments.

The DRAM timing settings are somewhat meager, offering Safe, Normal, Fast and Ultra Mode for Auto Configuration. In addition, the CAS latency can be set to 2, 2.5 and 3 cycles, the CPU / DRAM clock synchronization control can be set to either auto, synchronous or asynchronous, meaning that the two clock signals will be derived either from a single clock or generated individually by the two separate clock generators.

Keep in mind that CAS latencies require the equivalent pipeline stages in the DDR chip output path and most current PC2100 chips do not support the CAS-3 option. Setting the system to CAS-3, therefore, will cause failure to POST in most cases since the CMOS will try to force invalid mode register settings on the DDR chips.

The only way out is to open the case and reset the CMOS to default values.

Another issue is that by default, the CPU is recognized as 100 MHz FSB. The potential problem with this is that if the CPU/DRAM synch is set to to Synchronous while using PC2100 memory and without adjusting the FSB to 133, the system will not initialize either. Open the case again and clear another CMOS.... !

The two other settings are:

• DRAM Background cycles which appears synonymous for the address command decode latency (CMD Rate)
• LD-Off DRAM RD/WR Cycles which is otherwise known as fast RW turnaround or bus latency.