Shuttle SN85G4 XPC ReviewFormer staff writer -
The popular Phoenix AwardBIOS is used for the SN85G4. Shuttle has done a few modifications to the BIOS for us overclockers out there.
There are a few different options under advance chipset features. The most noticeable of those changes are the LDT (Lightning Data Transport) downstream width, and LDT speed. The LDT options controls the speed and data width of the Hyper Transport buss lowering the LDT speed can have adverse effects on system performance. There is the option for 4X LDT speed, but even at stock speeds setting it to 4x will result in the system not posting. The only down fall to this is it sets the Hyper Transports speed to 600mhz (DDR1200MHZ).
Under pc health status, you have the ability to monitor voltages and select fan speeds. Thru the bios you have a few options for fan speed Smart Fan, Ultra-Low, Low, Mid, and Full. The smart fan option worked very well and the system was quiet, but on full speed, the fan can get a little annoying.
The SN85G4 BIOS allows control over memory speed, and CAS latency’s. Inexperienced user might find the max Memclock setting confusing when it comes to overclocking. It only allows you to select a max of 200mhz which might make you think that the memory cant be overclocked past 200MHZ, but the 200MHZ setting acts the same as a 1/1 ratio or synced.
I really liked the voltage options Shuttle include in the SN85G4’s BIOS. For the cpu you have the options of .80 to 1.70 volts. This allows a .20V max increase in Vcore voltage form the stock 1.50V of the Athlon 64, which is adequate for some overclocking. The only thing I didn’t like was the low voltage settings some inexperienced users might unknowingly set this to low. You also have plenty of Vdimm voltage ranging from 2.70V to 2.90V in .10V increments. Chipset voltage ranges from 1.70V to 1.90V in .10 increments. The bios also included voltage options for the LDT buss from 1.30V to 1.50V in .10 increments. AGP voltage is also controllable too. For such a small system, I was amazed at the voltage options offered.
The CPU overclock option controls the speed of the CPU acting as a FSB, and allowing you to change the speed in 1 MHZ increments. You have the ability to go as high as 280MHZ way more than enough to satisfy your overclocking adventures.