Been poking around the interwebs and I don't see too many options for a high performance, low TDP desktop motherboard. I see some 17W TDP Core i3/i5 CPUs that are designed for laptops, I would imagine these offer at least 2-3 times the performance of Atom or AMD Fusion solutions.

Are options for a desktop board with a mobile socket still very limited / expensive? Or alternatively, are there non-atom desktop-class CPUs that can be tweaked to give laptop-like power consumption, while still delivering (at least) the performance of a Core i3 laptop?

Ideally I want a CPU with a max TDP of 25W or less, and ideally the whole system idles at 15W or less. VMware support is nice too.

Why the need for so low power consumption at full load? Below 15W idle is easy with Sandy/Ivy Bridge and the right motherboard, but max load will be in the low 50s. Isn't that good enough? What kind of server are we talking about here?

The official TDP values of individual CPUs are obviously silly. I know some people take offense for some reason when this is explained to them but you don't have to keep being a fool just because you were fooled once. Just stop paying attention to these values.
There are many desktop CPUs with a low actual TDP. Within the same type of CPU (like when comparing the various Ivy Bridge dual-cores which have the same GPU and efficency features), the actual TDP is a function of the clock speed. It's not directly proportional and you can lower your CPU's effective TDP by underclocking.

You will not get laptop-like efficiency in a server but desktop efficiency can nevertheless be pretty good.
The best non-Atom (and non-Geode, non-ARM, etc.) efficiency results have been obtained with Intel's DC-powered boards. These boards are limited compared to regular boards but that's the price you pay for efficiency.
If you use a board that's not DC-powered, keep in mind your PSU may consume more power than the CPU! Even with DC-powered boards, there are efficency differences between AC/DC bricks.

25W actual CPU TDP is not an issue. Just buy a slow cheapo. 15W idle for the system is achievable... until you add hard drives. Servers typically have hard drives so 15W may not be achievable depending on your storage needs.

I guess my concern over max TDP isn't really warranted, since it will be idling 99% of the time. The only reason I wanted a low max TDP is to have the to option of using a passive cooler that isn't very large.

Is there a way to safely lock (e.g. BIOS) some clock/volt settings so that the effective max TDP will be lower?

I guess a third option is to just use an old laptop. The primary disadvantage is not being able to use normal expansion cards for special purposes... (video import card maybe?)

You can lower the clock rate in the BIOS, which lowers the power consumption of the CPU. With the low power boards (I would recommend the Intel motherboards) you can usually not lower the voltage, which would be even more effective in lowering max power consumption. Power consumption while idle is not affected by this though, since these CPUs idle very effectively as it is.

But a small passive cooler will still be problematic I think, but that depends on how you define small I guess. If there is to be spinning HDDs in the system you might as well add a quiet fan, makes things easier.

Maybe building around Intel® Xeon® Processor E3-1220L v2.

When i was building my server, i was toying with v1 of it.... but as time passed, i decided to go toward a more flexibile route in case i wanted to go into zfs/vm... so went with E3-1230, but always wonder about that cpu with such low TDP. Hard part is getting one... the v1 was not retail but oem, so when i was toying with the idea i couldnt find anywhere online that take my cc that will have it in stock, now i see more v1 out there, but no v2......

There's USB-based tuner cards. Heck, there's tuner cards with NICs - you can just plug into the router.

I wonder if there's a guide yet on how to root a $250 Chromebook/throw a linux distro on it and use it as a server...

Something that I could capture HD Video over component or HDMI to make a homebrew slingbox with?

By "video import card" I thought you meant tuner card.

Hi cloneman

Two ideas

First

Have you looked at the Intel NUC lineup (you were not very specific about requirements)?

I'm thinking of buying one to use as my general purpose headless vmware server at home. Apparently they are just about to release an i5 version that have plenty of nice features.

http://www.tomshardware.com/news/Intel- ... 21946.html
http://www.computerbase.de/news/2013-04 ... d-core-i7/ (german site, but the specs are clealy visible).

Turbo Boost to 2.8GHz (http://ark.intel.com/products/64903/)
VT-x/VT-d
AMT 8.0
USB 3.0

Expandability is however an issue


Second

I currently have an E3-1220LV2 paired with DQ77KB. It is a headless VMware ESXi server. Power consumption is 10W idle using an Intel SSD + Dell 19V notebook adapter

The only issue I have with the board is that the pci-e port is x4 and not open ended, so I may have to "modify" the board if I wan't a larger than x4 card in the slot.

HD-PVR from Hauppauge. USB.

If OTA, the HDHomeRun is a good network based box.

Thanks for the tips guys, very interested in these options. NUC looks nice I'll look into it when it gets released.

The PVR stuff looks nice too. Can that hauppauge stuff be used with some sort of streaming solution that isn't tied to twitch or some other service? For instance a direct VLC stream or mythTV

I use it with SageTV (same on the HDHR). Not sure about the others, but I think so. There are 2 or 3 versions, newest has HDMI (No HDCP, but there is a way around that too)

My NAS machine (see .sig) uses less than 60W under load. It's also pretty much silent (only two 120mm fans at 800rpm).

I've seen what people do to crack HDMI encoding, I think you want to avoid that if at all possible. Analog video capture would use way too much disk space.

If at all possible use a tuner.

You might want to search again, it's MUCH easier/simpler/inexpensive than you think. I was truly shocked at how easy it was.

I built a NUC server two weeks ago; it idles at 10W and I've yet to see a peak reach 20W. Pleased with it, but expandability is indeed an issue; if I were doing it again, I'd buy the board and put it in my own case, as there's absolutely no room inside the Intel case to make any use of the two additional USB2 headers.

I can easily see me buying an i5 version in a year or two to replace my current "big iron" 6-core AMD server.