If your article was willing to look at a Pentium M with its pricetag, then perhaps you should consider an Xeon 50 watt processor? The Pentium M and the Xeon are probably pretty close in price. If you are looking for an office product it is hard to quantify the price of some of the newer processors just to get email and type a letter on Word, or use Excell. How much power does that really require?
Intel was claiming they were going to come out with a line of low-power desktop systems, but I have not really seen anything practical in that category from them. I guess they were not telling the truth. What I am guessing is that big business is just not buying the low power solutions. Either that or they are expecting the low power crowd to just go buy a laptop.
I know we can't review every piece of hardware in each review. But the addition of a PC Power and Cooling PS would be nice. They are one of the few good PS that don't use those useless "trendy" modular power cables.
For me, the main reason to choose low power components is for a Home Theater PC (HTPC). Lower power means less noise. So it would have been nice for this article to benchmark noise for the PSU and HDD. Also, there are fanless plug-in graphics cards that are particularly good for HTPCs (e.g. HD picture enhancements, HDCP, etc.). Here's an example: http://www.newegg.com/product/product.asp?item=N82E1681...
I notice that you do not cover underclocking/undervolting the video card, on most nVidia models there is a simple "Coolbits" interface available that can set the core and RAM clocks for 2D and 3D operation, unfortunately the low-end cards usually set them the same, and most cards have the RAM set at the same speed all the time.
Some cards have Voltage control, and some cards can be easily modified with a simple resistor or bridge swap to function on low-power. In fact the discrete card may be possible of much less power usage than an onboard graphics due to its mod-ability and the enhanced efficiency of newer silicon. Offset a bit by the PCI-E bus power required, but that shouldn't be a lot.
I mention because sometimes you need low-power and functions that integrated graphics can't perform (HTPC Video outputs for example, or multi-monitor support), I notice that the Geforce 6150 and 7050 integrated DVI/HDMI HDCP and Component output motherboards were not considered in the line-up, although they offer HTPC outputs, dual display, and nVidia's superb driver functionality.
On the subject of processors, you don't mention underclocking at all, I have been able to successfully use my PC at 500Mhz for extended periods of time (AMD AM2 x2), and only noticed a minor stutter problem when playing back a 720p HD WMV, at which time I re-clocked the PC to 800Mhz and was able to watch just fine.
The OS and software being generally inefficient (both in terms of resource usage and taking advantage of proper acceleration), Software just isn't written properly most of the time, and why should it be if the recommended processor is a 2GHz dual-core machine that can chew up anything, even something taking 100 times as many processor cycles as it should be?
The problem also stems from "General Purpose" processing power being used for Massively Parallel processing tasks such as Video Editing and playback, we are at the point where it is a gross waste of system resources when the technology exists to put co-processors on the die (Kudos to AMD for putting this in the roadmap), not to mention the lack of a standard to put video Chip/Card acceleration to good use (Kudos to AMD/Ati and Nvidia for their work on the acceleration). Microsoft again wields a double-edged sword with the Vista OS, they are doing a good thing by standardizing the requirements of Video cards to accelerate movies and the desktop environment, but at the same time they are saturating the Video card and processor with useless eye-candy in an attempt to make the end-user want to use the OS.
The worst offender is the HDCP built into Vista, where an unbelievable amount of resources is put into assuring that the HD video gets a Ring 0 kernel seat to spy actively on all parts of the OS, doesn't that waste system resources? Just think of the bandwidth/processing power to decode and display the video, and then imagine the OS trying to actively sample and guard against that being read or changed!! BOOO! Anyone stealing the movies is going to use Bittorrent instead of buy the hardware just to rip the movies, and this re-freaking-diculous "copy protection" scheme is likely to force legitimate purchasers of the HD to rip/download their content for use on the much more streamlined Linux or W2K/XP OSes
One of the reasons I switched from CRT to LCD was because of the huge difference in power consumption. That and less glare, widescreen, upgrade in display size. A little sacrifice in color accuracy and (not really perceivable) response time.
I used to custom build PC's... my last machine was a Barton core ULV (35W) 133x12.5 mobile athlon, which I clocked at the LV 166x12.5 45W envelope, and a radeon 9600 (the best passively cooled card I could get at the time), for quiet operation... I was sick of wind tunnel machines. I now run a 20" intel imac, which burns 65W idle or 75W in general use, I've almost hit 90W in doom III. It burns 2W when it goes into sleep mode (15 minutes idle by my settings). Yeah, the x1600 mobile won't knock your socks off, but you can't get that kind of performance out of your integrated machine that burns far more power for a home built tower. Plus it is quieter. Consider this...