As discussed, support for a 533 MHz RDRAM clock is not officially supported by the 850E chipset. Any manufacturer wishing to support PC1066 RDRAM needs to choose components carefully to make sure the board will run with stability outside the specifications.


Choosing an appropriate Direct Rambus Clock Generator (DRCG) is particularly important. Iwill has selected ICS' 9212AF model. We scoured ICS' site, and found no mention of this particular part. We did find a datasheet for a similar part, however, designed for PC600/PC800 RDRAM (300/400 MHz), and found the following:
http://media.hardwareanalysis.com/articles/small/10463.jpg">The datasheet shows that the older controller does in fact have a setting for PC1066 RDRAM (using a 66.67MHz RefClk and 8x multiplier internally), so it's likely the 9212AF controller used on the board is merely a slightly improved variant of ICS' older designs, validated for 533 MHz operation.


Intersil's HIP6301 voltage regulator is a common part, seen on a wide range of current motherboards. It supports a 5-bit voltage select (corresponding to the Pentium 4's 5 VID pins), and is capable of output voltages from 1.100V to 1.850V. As mentioned, these voltage settings can be manually specified in the BIOS. When selected, the board overrides the VID inputs to the regulator from the CPU, and inputs its own selection based on the BIOS setting chosen.


Iwill uses low-ESR capacitors manufactured by Her-Mei in Taiwan. Our experience with Her-Mei capacitors has been fairly positive thus far (failure rates are certainly lower than weaker Tayeh or Jackcon capacitors), although they may not be of the same excellent quality as the Nichicon or Sanyo capacitors Intel uses on its own desktop boards.




(From left to right) Realtek's RTL8100B networking controller provides 10/100Mbit on-board networking capability. Iwill likely opted for the Realtek part over the networking offered by the ICH2 for ease of implementation. C-Media's CMI8738 6-channel analog/digital sound controller provides the on-board sound in either 2, 4, or 6 channels, depending on the optional riser included. Winbond's W83637HF hardware monitoring controller provides surveillance of the standard voltage rails, as well as two fans and two temperatures (including the Pentium 4's on-die thermistor).