I have 2 dockstars and one GP+. In preparation to put on new heat sink, I removed the heat plate on GP+. Then I thought, "I wonder how hot dockstar gets in open air". So I leave dockstar and GP+ CPU in open air, disconnect all network connections. And after 2 hrs idle time, I did my finger test (Still waiting for my cheap IR thermometer). CPU in GP+ is burning hot. CPU on dockstar is warm. I touched the memory chips. And it's same story, memory chip on GP+ give me burning sensation. Yet, memory chips on dockstar is just warm.
Dockstar's power supply provides 12V, and I'm sure there are step down DC/DC converter to down-convert to whatever voltage Marvell CPU needs (2.5 or 3.3V?? Maybe even 1.8V?) As far as I can tell, dockstar and GP+ have same CPU, operate at same frequency: 1.2GHz. And I think even the DDR2 memory is same at 400MHz. So first possible explanation come to mind for the temperature difference is maybe GP+ is operating at higher voltage. Anyone have schematic that shows which DC/DC converter or voltage regulator were used on GP+ and dockstar? Or maybe someone have means to measure Vcc off Marvell CPU directly?
Could the additional power burned was due to 3 DDR2 memory chips?
Thanks in advance for any suggestions.