I recently bought an Abit A-S78H motherboard with 780g chipset. There are a fair few reviews of this chipset on the net, but most are focused on details and benchmarks rather than what the boards are like in practice.
This chipset seems almost too good to be true. I wanted one for a HTPC, but I am also looking at getting one for a NAS too. The main attractions are the built-in Radeon 3200 graphics with HDMI, DVI and VGA output, the six SATA ports and low idle power consumption (measured at 32W by SPCR with a good PSU).
The Radeon 3200 is fully capable of decoding H.264 and VP-1 video, meaning even a slow CPU can cope easily with 1080p Blu-Ray and MKV rips. My next post will cover using that in more detail. HDMI output on the board is really handy as it is the best way to connect the system to a TV, and it supports audio over HDMI so you only need one cable which can be 10+ meters long. In practice, it works really well, the only down side being that my TV does not auto-switch to HDMI like it does with RGB SCART.
I read that the on-board might not support 7.1 output, only 5.1 over HDMI. I have not tested it, although it seems to be a bit of a moot point because if you have a 7.1 system you probably have a receiver which can decode Dolby Digital and AC3, so you would pass that through anyway which definitely does work. Otherwise, the PC can decode 5.1 to 6 digital audio streams and pass them over HDMI.
Six SATA ports are obviously ideal for a NAS. In tests they seem solid, and support AHCI mode as well as native SATA and legacy modes. One thing I did notice is that in AHCI mode with Vista power management (spin-down) does not seem to work. In native SATA mode everything is fine. SATA seems to have a low CPU overhead, and supports various RAID functions (although I never use on-board RAID).
All boards with this chipset I have seen run passively cooled. The northbridge heatsink gets hot to the touch, but not worryingly so. Combined with a good PSU, Ninja CPU cooler and suspended 2.5″ HDD the system is almost totally silent. Quieter than my XBOX, in fact, which has a modded fan.
AMD is on to a real winner here. Good performance, rock solid stability, good drivers (hi nVidia nForce) and an abundance of features.