Intel DH77DF vs. Asus P8Z77-I (power consumption)

[jimmerthy]

I’m working on a project to run my VDSL modem, gigabit router and home server primarily from PV solar. I'm not doing this to try to save money on electricity - I'm doing it so I can learn about off-grid solar.

The solar battery voltage will be 24V (nominal).
I plan to run the 12V devices (VDSL modem, gigabit router) from one of these…
http://linitx.com/viewproduct.php?prodid=12679
And the PC from one of these…
http://linitx.com/viewproduct.php?prodid=11664

All of the equipment will be located in a large cupboard under a staircase in an electrical cabinet, so there’s no requirement for the system to be silent.

The PC will have two roles.
- It will drive the TV in my living room via 720p HDMI over CAT.6 (media playback)
- It will host a 4GB RAM virtual machine which will run web, sftp servers and act as a VNC application server. Occasionally it will need to do some hard work.

I’ve decided to use an i5-3570k because it offers HD 4000 graphics and I could re-use the CPU in an overclocked desktop PC in a year or so. I’m a stuck on the choice of min ITX motherboard though. I’ve narrowed down my choice to...

- Intel DH77DF
- Asus P8Z77-I

I like the idea of capping the CPU to 2 cores to limit peak power consumption (as mentioned in this thread) – both boards support this. I’d also like to try to under volt the CPU to reduce power consumption further. This isn’t possible on the Intel board though.

The popular wisdom here seems to be that if you want low power consumption then choose an Intel motherboard every time (e.g. DH77EB or DH77DF). I guess I’m a bit put off by Intel boards because of their reputation for non-tweakable BIOSes.

This Z77 group test review claims that the Asus board has amongst the lowest idle power consumption in the group, so I’m keen to see what people here think of it. The board has some custom power management chip (Asus call it an EPU) and supply ‘AI Suite II’ Windows software.

I’d use 8GB (2x4) Samsung 1.35V DDR3 as its getting good reviews at the moment.

Storage will be a Crucial M4 256GB SSD and a 2TB 3.5" green drive. The PC will use gigabit Ethernet and will have a USB TV tuner attached.

The system won't run on solar all the time. I'm going to implement a mains failover for when the battery voltage falls below a certain threshold.

Any thoughts or opinions on this before I spend some money?