Energy efficient PC's - part two

In the previous post, I discussed a few ideas on energy efficient CPU's. The main problem in this area is that good documentation and metrics are amiss.
A further caveat that the end-user has to be aware that the CPU model number is not enough to give an indication of energy usage. For example an "AMD Athlon 64 3800+ AM2 socket" CPU may be (45Watt, 62Watt or 89Watt) TDP. To know the Watts TDP, you need to know the AMD part number, or nickname eg "Windsor", "Lima" ...

The Onboard video option:

Onboard video (integrated into the motherboard) would be more energy efficient than a separate Motherboard/Video card, but with poorer performance. To some extent this assumption has held true over time, but in the recent times onboard video performance has improved a bit so they are often reasonably game-capable.
Normally onboard video do not have their own memory (RAM) and this slows them down. HyperMemory(ATI) TurboCache(NVidia) Technologies allow usage of PC system RAM as video card framebuffer memory. It relies on fast data transfer through the PCI Express bus.
It is not really possible to compare integrated and non-integrated video, as the integrated video performance is heavily depend heavily on the Motherboard design, especially where the video chip requires access to system memory.
The best onboard options seemed to be the following chipset combinations:

• AMD 690G Chipset : ATI Radeon X1250 Graphics
• Intel G965 Express Chipset: X3000
• Motherboard (Eg Asus, Gigabyte) : Geforce 6150

From various tech reports (eg bit-tech , techreport ), it seems that for good performance of onboard video, you may want to opt for the AMD or a Geforce 6150 solution. Apparently you can play most games on the AMD X1250 or GeForce 6150, but not on the Intel X3000. The X3000 integrated graphics was built for Windows Vista certification. After AMD bought ATI, Intel was in a big hurry to develop an Graphics Media Accelerator (GMA) solution. (Apparently they originally planned to work with ATI on a video GMA). So the AMD 690G Chipset ended up being a better games solution than the Intel G965 Express.
In addition, it seems that power usage of the AMD 690G is overall a bit better than that of the Intel G965. Looking at the energy usage, the real difference is when the systems are idling (The AMD uses less energy). I feel vindicated about my comments about the Intel hype in this area. And in the test mentioned, they were using a power hungry AMD Athlon 64 X2 5200+ 2.6GHz. So one could even improve on that power performance of the AMD solution (more than one can on the Intel solution).
In conclusion if I were to buy an integrated video and motherboard, I would combine the AMD 690G with one of the low power AMD - AM2 chipset cpu's (35 Watt or 45Watt). The AMD 690G has better power efficiency, games capability, and would be cheaper
On the other hand Intel has good open source drivers for its graphics chips, so if you are an ardent Open Source/Linux supporter, you may opt for the Intel G965.
Some more in the next post.