Is it possible to undervolt a 35 W TDP Sempron?
The EE Sempron already has a lower supply voltage than the standard Sempron (1.25 vs 1.4V); the question is whether the EE Sempron is simply a normal chip that has been undervolted at the factory (altering the VID value), or it is made of "better" silicon, which is more able to cope with lower voltages.
To cut a long story short, the answer is yes, but it is questionable whether the price premium of the EE is worth the energy savings over an undervolted normal Sempron.
I think for ease of "efficient pc" assembly, yes, the EE parts are preferable. Presumably, they're set up so any mobo w/an uptodate BIOS just recognizes & sets the required voltage settings correctly. No SI wants to mess w/individual tweaking and checking of CPUs/mobos in every system. But the EE Sempron parts are not priced at AMD -- they're obviously not available for general purchase yet. Since the EE A64s are now priced the same as the standard ones, tho, there may be no price hit when they do become available.
Hmmm, my retailer has the 35 W Sempron in his price list, and relatively cheap too at EUR 73.99, but delivery time is supposed to be more than 10 days (which can be anything). The Sempron 64 3200+ can be delivered between 1 to 5 days. I'm thinking more and more of building the first few systems myself to save time and money and gain some more experience along the line. It'd also give me the chance to do some measurements to see how efficient the system actually is. I'd undervolt the CPU's just a bit (if the 35 W Sempron isn't available), not to the limit so as to avoid problems. I think with good preparations, ie read everything again on SPCR, and a bit of luck I should be able to pull it off. Anyway, that's for the future but it's good to know I've got a few more options besides the 35 W Sempron 3000+.
So, how's about this 'rough draft':
Sempron 3200+ (1.9 Ghz)
Asrock Alive NF4G-DVI
2 x Kingston ValueRam 256 MB, PC4300, 533 MHz, 4 (for now, haven't checked compatibility yet)
Hitachi Travelstar 5K100 60 GB S-ATA
Samsung TFT SyncMaster 710N 17 Inch, 12 Ms (probably, still have to found out about power consumption)
Logitech UltraX keyboard+ opt. mouse
Logitech OEM speakers
Multiple socket with switch
Win XP Home (+coupon for Vista yay)
That's just about EUR 690 (USD 885). If I can find the right 20 W monitor it should be able to run idle at around 60 W in total?
ecit: I agree with you, breunor, a free and efficient OS such as Linux would be preferable, but it'd make my system even more unattractive than it already is. I want to try and appeal to the growing group of people who are becoming aware of the seriousness of environmental issues (as an aside: I personally don't know how grave it is or will be but the media are jumping on it more and more, so before you know it we'll have a hype on our hands as big as the global anti-smoking campaigns I think). If I am too green, people won't take notice. I just want to make this group use a 60 W machine instead of a 120 W machine with specs they don't really need.