Hi,

Atom motherboards show idle of around 20W in SPCR tests whereas Atom netbooks typically consume around 10W idle (and sometimes with screen on).

Any idea on the potential sources of this 10W difference?

Is it possible to buy current motherboards+CPU with 10W idle or less, Atom or other x86?

What are your lowest idle systems with non Atom CPUs?

Thanks!

dual-core vs single-core Atom, 4W
2.5" HDD vs 3.5" HDD, 3~5W
power supply inefficiency


10W idle, probably going to be difficult with currently available platforms. Something VIA-based might work. Zacate's coming out soon and it's pretty promising if you want an ultra low power build.
AMD's Bobcat APU benchmarked: the age of the Atom is at an end

Wow, 9.3W idle that's good indeed I guess SPCR will love this one .

And quoting anandtech:

The chipset also makes a huge difference. I'm not sure about the more recent versions, but it was almost impossible to find a mini-ITX board with the 945GSE mobile chipset a year ago. Everything had the 945GC chipset. I think the 945GSE had a TDP of ~2W, and the 945GC had a TDP of ~8W (which, I will note, is several times that of the atom! What a waste!) IIRC.

That said, I built a system with the D945GSEJT board from intel, which has almost the same hardware as my ASUS 1005HA netbook, but the netbook idles ~11W (AC in) and the D945GSEJT, with a 2.5" drive, the same ram, and no screen, idles at 16W (AC in). I might blame this on the crappy wall wart supply, though. Intel's minimalist figures for a thumb-drive boot are ~9W DC in. I guess this is still a bit worse than the netbook.

As others have stated, the chipset matters. Mobile gear is designed to consume less power.
There are low-power Atom chipsets. You'll recognize them by the CPU deisgnation which starts with Z. These consume a good bit less than the usual mobile Atoms systems. I don't know consumers can can buy them separately but I recall Dell sold fanless netbooks based on these. Fit-PC also makes very small desktops featuring that platform.


a laptop surely (don't know which one)

Actually, the 945GSE has a TDP of 6W while the 945GC has a TDP of 22.2W. Meanwhile, the Atom N270 has a TDP of 2.5W while the desktop Atom 230 and 330 have a TDP of 4W and 8W respectively. Hence, for the netbook space, you're looking at 8.5W system TDP while for the desktop variants, you're looking at 26.2W for single-core and 30.2W dual-core.


The codename for the chipset is Poulsbo and the Atom Silverthorne. Chipset is the US15W with TDP of 2.3W and CPU is the Atom Z5xx series with TDP ranging from below 1W to 2.5W (albeit the most common is 2W). It's usually what's inside low power tablets/slates. Hmm, I've actually got a system with this (Viliv X70 EX). I've never measured the power consumption, though.


Lowest idle power, is an Asus UL30A-X5 (Intel GS45 + Core 2 Duo SU7300). Plugged directly into the socket without the battery installed and screen at dimmest, Kill-A-Watt reading is 7W during internet browsing. It has awesome battery life. I believe it even has lower idle power consumption than my brother's Acer netbook. If I remember correctly, that one uses 10W idle (albeit the screen's dimmest setting is brighter than my Asus).

Obvious contenders for low idle power:

Mac Mini (<10W idle) - a laptop in desktop clothing (Core2Duo)

viewtopic.php?f=30&t=59331


OLPC XO-1 (laptop) - idle about 7-8 W, but if you shut off things like the screen backlight and the radio you can trim that by a watt or two.
(Of course the processor isn't up to Atom speeds.)

I'm disgusted all over again!
Perhaps I was remembering the 270 vs 330 atom figures when I quoted my (incorrect) figures. I still don't understand the market for a 30W AC idle atom system

Hmm, idle is slightly less than that. I believe my D945GCLF2 build consumes 27W idle. I think the system it replaced was consuming 70W idle.

Back when the Atom was released, there were few options, particularly in the Mini-ITX space. You need a magic combination of motherboard and undervolting to even reach 30W idle. Most desktop systems sit at around 40~60W. Now with newer chipsets and processors (Clarkdale in particular) as well as power supplies with better efficiency curves, getting 25~30W idle is becoming pretty common.

Rant against Intel and the Atom all you want but I'm grateful they made Mini-ITX more mainstream (granted, I think the D201GLY with Celeron was Intel's first M-ITX board). VIA may have introduced the form factor but it was because of Intel that it became as popular as it is now. If not for them, going M-ITX would probably still be limited to specialty shops and motherboards would cost minimum $150 with higher end boards going for $500.

Thanks for the links !

Any SPCR user with a Mac Mini idle and in load measure in real-life (the discussion seems to quote manufacturer numbers)?