If you look at the spec sheets for the S479 motherboards, they generally only list support for Merom and Yonah; the Asus N4L-VM DH is an exception and lists Celeron M 4xx chips.
I can confirm that the Gigabyte & Abit S479 boards also support Celeron M 4xx, as do at least some of the Aopen boards. This is with the current BIOS releases; Iâ€™m not sure about previous versions.
Even though the Celeron M series do not support Speedstep, it isnâ€™t proving that much of a penalty in the power consumption stakes. Hereâ€™s a comparison that I ran on the following system:
Abit iL-90MV, 1GB DDR2-533, Seagate Momentus 5400.2 120GB SATA, PicoPSU, EPS 55W 12V power brick.
Celeron M 420
Idle - 1.6GHz, 1.216V â€“ 24W
Load - 1.6GHz, 1.216V â€“ 28.5W
Core Solo T1400
Idle â€“ 1GHz, 0.95V â€“ 20W
Load â€“ 1.66GHz, 1.1V â€“ 26W
Core Duo T2600
Idle â€“ 1GHz, 0.95V â€“ 22W
Load (1 core) â€“ 1.66GHz, 1.05V â€“ 32W
Load (2 cores) â€“ 1.66GHz, 1.05V â€“ 36.5W
The Core Solo and Core Duo have a FSB of 667 and a L2 cache of 2MB versus 533 and 1MB for the Celeron M. The load figures were measured using Prime95.
The Core Solo and Core Duo were multiplied reduced to get as close to the Celeron Mâ€™s 1.6GHz as possible.
Itâ€™s surprising to see how inefficient Core Duo is when only a single core is running at full load. The second core must be consuming quite a bit of power whilst doing nothing. This seems to be confirmed by the fact that the second core only consumes an extra 4.5W at full load compared to idle.
The downside for Core Solo is that it is priced almost the same as Core Duo.
The Celeron M 4xx series has a list price in the UK starting at Â£35 compared to ~Â£135 for Yonah/Merom. Core Solo and Core Duo chips are available on eBay for much less than this, itâ€™s too early for Merom to be appearing on eBay at friendly prices.
For those of you wondering why Iâ€™m posting so much data on low power computing on SPCR, please read this thread
which I started today.