Will this work? A8 in M350

Another thing about efficiency. The picoPSU's efficiency quote is in the DC-DC conversion process. The AC-DC conversion process, which happens in the laptop brick, is the one that really counts since it's more inefficient.

Wow, thanks for all the feedback and help! A few points about this build:
- The A8 was a gift (and is still unopened). I can't return it and I have tried to sell it but haven't had anyone interested in it. I won't sell it for less than the cost of replacing it with a <=65W CPU.
- Usage is mostly for movies and the machine will be turned off when not in use. I expect it to be on 2.5 hours at a time. Probably will be used once a week (not that that matters for this discussion). No gaming, no running Prime95.
- I am fully willing to undervolt and underclock this to the point that it performs like a lower tier part. It makes more sense to me to do that than to take a loss selling the A8 for really cheap and then buy something like an A6 65W.

@Mick1152: Thank you for posting those numbers. The power draw you are seeing matches what others have posted and is the reason why I think I can pull off a machine like this using a 100W part. With my usage, it simply won't be running full tilt. I just need the machine to make it through a movie without overheating.

@DavidT99: I hadn't considered the Akasa case before. In general, Akasa products are very difficult for me to get (I am in Canada), but I have the option to ship to a friend in California and pick it up later. Do you have experience with the case? It looks to sell at $100 or so with a 80W PSU. Replacing the psu would put this close to $170 with a 150W PicoPSU.

@bluray: Thanks for the link to the build using the ISK 310-150. I am considering it although i would lose Vesa mounting and it is pretty long compared to the M350 or ISK110.

I think my options so far are:
- M350 with a 150W PSU for about $105: Might get too hot. Not sure if I can put two 2.5" SSDs in there without interfering with the CPU cooler.

- Antec ISK 110 Vesa ($75) and 150W PicoPSU kit ($70) totalling $145: Seems like a good option. Vesa mountable and support for two 2.5" SSDs. No optical drive, but that's ok. Relatively expensive.

- Antec ISK300-150 for about $75: Optical, two 2.5" drives. Not a bad option, but no vesa mount, it's a pretty long case, and I expect it will be a lot noisier (PSU fan and Case fan) than the other options.

- Habey 800BL ($65) and 150W PicoPSU kit ($70) totalling $135: OK option. The included PSU is 120W but with a 60W adapter, so I might as well replace the whole PSU with a pico (or should I only do the adapter?) Case seems to be poorly ventilated.

(2012-07-31 18:48)twelvebore Wrote:  

(2012-07-31 12:48)Zenith Wrote:  If these are the numbers...at 80% efficiency a 150 watt power supply it is a bit underpowered...this cpu needs at least a 180w/200w power supply.

Efficiency works the other way. A 150W PSU will deliver 150W, and pull 150W * 1.0/efficiency from the wall. It doesn't pull 150W from the wall and deliver 150W * efficiency to the motherboard.

80% efficiency means that on 100 watt pulled from the wall only 80 can be used by motherboard and other hardware 20 is lost in heat during AC to DC conversion.

On the 143W showed by Kill-A-Watt on this cpu power losses are already accounted, so for many people 150w is the perfect psu but I prefer a little more "room" on power supply.
Usually power rating is nominal or peak power not actual or sustained. On pico 150watt is a peak power and you have to provide good ventilation and should not exceed 60 seconds.
It can work but I think that is not 100% reliable.

(2012-07-31 19:15)gomiflo Wrote:  - Habey 800BL ($65) and 150W PicoPSU kit ($70) totalling $135: OK option. The included PSU is 120W but with a 60W adapter, so I might as well replace the whole PSU with a pico (or should I only do the adapter?) Case seems to be poorly ventilated.

I would add to your list the [http://www.ecosmartpc.com/ei5.html]Realan E-i5[/url]. Realan is who makes the Habey EMC800 but the E-i5 has better ventilation. It also hold 2 x 2.5" whereas the EMC-800 can only do so if you take out the optical and then you have a big open slot in the front of your case. The E-i5 can also be purchased without the power supply saving some money you can put towards the picoPSU. Factor shipping into the price of the Habey and the E-i5 is pretty comparable.