Need for heatsink, and CPU underclocking

[kilowatt]

Greetings,

My application of the FIT-PC2 is onboard a small unmanned aircraft. I have two questions:

1) Under what conditions is the optional heatsink typically needed? We expect ambient air to be around 25-35C. We are unsure of the CPU load at this time but expect it will average around 50%.

2) Can the CPU be underclocked? That is, can we order the 2GHZ model and tell the BIOS (or with jumpers) to run it at only 1 GHZ? If so, what kind of heat or power consumption might we change?

Thanks very much,

--E

[yogev_ezra]

1) In your described conditions the heat sink is not needed. It could be needed if the ambient temperature is high or if FitPC2 is placed inside a closed plastic box with no air ventilation.

2) You can underclock the CPU via BIOS but it's not recommended since:
a. It changes the FSB speed and not the CPU multiplier (since the CPU multiplier is fixed and cannot be changed). Some FitPC2 components (like LAN etc.) do not work good with non-default FSB speed.
b. The power saving from such change would be very minimal. It is easier and more cost-effective to order 1.1GHz CPU and run it at full speed, than underclock 2GHz CPU.
c. If you do want to save some energy then use SD card or SSD instead of regular hard disk (this also makes sense because of aircraft usage), and you can also disable unused components in BIOS (for example, disable LAN and SDIO if they are not used - this will save some energy).