Which Server CPU?

[ProDigit]

Hi all,

Looking for a cheap server I can buy off Ebay second hand.
I hope to buy mobo, CPU, and case separate.
Here are what I would like:

Preferably a MicroATX or mini ITX (small) case and mobo.
Support for fast RAM. Preferably >DDR3, DDR4, or LPDDR4. ECC is not necessary.
Price for case and Mobo preferably below $350.

I'm still looking for options, but all will be based on the CPU.
I've looked around, and my brain goes haywire on processors.
But I've narrowed it down to a few Xeon processors of not the newest generation.
ARM won't work for my applications, and AMD is harder to find fitting parts for.

So Xeon CPU, that needs:
8+ cores with hyperthreading or 16 individual cores (or more, the more the better).
Thermal envelope below 85W
Price <$250 preferably below $100 second hand.

I'd probably save money on an older processor using an older die (22nm vs 14nm), and lower peak CPU frequency.
I prefer more cores over higher CPU speed, as my computer will be doing a lot of parallel tasking (mostly compressing or converting files, and folding@home projects).

I don't want a dirt old CPU. Prefer as new as possible, but I understand that at some point there's a tradeoff (where it makes no sense anymore spending top $$$ for a processor that's just 15-25% more energy efficient).

Ideas on CPUs?

 

[Yeroon]

Have you considered a last gen ryzen 7, like a 1700? Theres a few threads that have mentioned them in the $150 range (new, newegg?), used on ebay the 8c/16t ryzens are also similar in price. Motherboards are new, fast ram support is pretty good, and a ryzen at 3.3-3.5ghz is pretty low power use. (65w tdp)

x79 matx with something like a e5-2650v2 (80w 8c/16t) or e5-2650Lv2 (70w 10c/20t) might be doable in that price range. Quick cinebench score check show them trailing the ryzen 1700 by a decent margin though, and I'm not sure what the newest cpus are that function in a x79 board. X99 seems to add a bit to cost.

Might be a good idea to see what instruction sets like avx2 the xeons have that the ryzen cpus dont, for the applications you run.

Edit: I'd like to clarify that the $150 price for the 1700 was sale prices that have popped up, and not a regular list price.

 

[Rifter]

If you dont need AVX2 then first gen Ryzen is your best bet in that price range.

 

[ProDigit]

Went with a Xeon 2560L V2.
Bug bit me, and upgraded to 3900x, then bought another 3950x, and I now have a second 3900x arriving soon!
Performance of the ryzen is lots faster, even at only 65W (eco)!