I am looking into replacing my home server / NAS, and I considered the atom server chips, but they seem just so expensive for their computing power, and also not very power efficient. The 8 core C2750 has a passmark of 3800[0], with an abysmal single thread performance of 579, and still has a TDP of 20W, and the mobo+cpu assemblies go for ~400$.

For way less, if you're willing to five up on ECC, you can get an i5-7500T and a pretty good motherboard, bringing your TDP to 35W but having a passmark of 7055, and most importantly, a single thread rating of 1924.

This might not matter much if you're use is exclusively NAS, but I will probably end up running some virtualized or containerized server, or streaming video possibly transcoding on the fly, and I'm afraid the Atom might become a bottleneck.

Is there a solution that is somewhat competitive with the i3/5/7 on price and power, and has ECC? And, ideally, that comes in a Mini-ITX form factor?

[0] Obviously the PassMark score is only a ballpark estimate to get an idea of how fast is a chip, but still.

Look at Xeon E3, for example: https://www.newegg.com/Product/Product.aspx?Item=N82E1681911...

Thanks. It looks there are reasonably priced mini-ITX boards that support Skylake Xeons (a note to this that are considering this: v5 E3 (Skylake) use the same socket as Cores, but need a different chipset).

The 80W TDP worries me about though, cooling, noise and money/pollution wise (the extra 45W make around 400kWh/year).

Considering the CPU will be idle most of the time, do you have figures about the actual idle consumption of an E3 based machine?

There are also lower TDP models like http://ark.intel.com/products/53401/Intel-Xeon-Processor-E3-...

My home server with a Xeon E3 1240v5, 5 3.5" hard drives, one SSD, a SAS HBA and a small discrete GPU idles at 71W as reported by my UPS. I haven't made any special effort to optimize power consumption yet.

If you end up buying high TDP chip, you can simply cap the clock either in BIOS or in kernel to save power.

Aren't the Avoton chips the ones that is causing Cisco to have to replace a crapload of network gear?

Yes. The C2xxx series Atom has the errata. [0] It's not just Cisco gear affected, but Cisco are being the most proactive about replacement.

[0] https://www.theregister.co.uk/2017/02/06/cisco_intel_decline...