Let's assume a generic system like this:
- Two modern multi-core CPUs, like a Xeon Dual Core
- 2x 7120M, 3.00 GHz, 95 W power dissipation each, according to Wikipedia
- 2x 835Watt PSU (redundant)
- 8GB RAM
- 4 HDDs
- no video
What would such a system approximately draw when I switch it on and send it to BIOS? Idling...