New Unraid build - sanity check

[julianhj]

I've been using Unraid for quite a few years, running a couple of HP Microservers (Gen 7, N54L). It's got to the stage where basic tasks see the CPU pinned to 100%, and I've reached the point I want to start running a Windows VM or two alongside Plex and my usual file server usage. I'm not planning on gaming, so I don't need a particularly powerful machine. I'll be moving my current HDDs over.

With energy prices doubling (soon to be tripling?!?) I'm thinking about trying to be as power-efficient as possible. With this in mind I'm not sure whether Intel gen 10/11/12 is better. I've drawn up the following spec list and wanted to check whether anyone had any views on any improvements before I make the purchase:

Intel Core i3 10105 Comet Lake CPU
ASUS Prime B560M-A Intel Socket 1200 Motherboard
Corsair Vengeance LPX 16GB (2x8GB) Memory Kit PC4-28800 3600 DDR4 DIMM C18
Samsung 980 1TB Internal SSD M.2 2280 PCIe Gen3 x4 NVME
Fractal Design Meshify 2 Mid Tower E-ATX Case
Corsair RM750 RMx Series 750W Fully Modular PSU (80 PLUS Gold)

Key questions I have are:

- could using an 11th or 12th gen CPU lead to greater power efficiency, particularly at idle?

- is it worth speccing 32GB rather than 16GB for my intended usage?

- is it worth speccing an i5 rather than an i3? are there any downsides other than purchase cost?

- is there any benefit in specifying a smaller PSU, i.e. for greater efficiency?

 

[b0rn2sk8]

Yes to the point on the PSU, it’s massively overkill and will not be very efficient at such a low power draw.

A good 400w PSU will still be overkill for that.

 

[Avalon]

Context is everything. You ask us to advise on CPU/RAM but give us precious little in terms of anticipated usage beyond a windows VM or two. Based on such a vague scenario take everything from here on as general advice rather than specific to you...

In general terms, people usually run out of RAM before they run out of CPU in UnRAID and most virtualised/shared environments, exceptions exist, but if you are one, you'd generally know that already and presumably have mentioned it.

Leave the i3 as is - it's arguably overkill and a used purchase later on will be cheaper if/when required, the only significant usage you mention is Plex, this can run quite acceptably on a Pi, but if you're doing the other associated things such as the *arr's and SAB/Get or similar, then the RAR/PAR work is reasonably CPU and IO intensive, especially if you have a fast connection. Either way 16GB is likely way more than enough at this stage, especially considering where you're coming from. The other usage you mention is a Windows VM or 2... again no detail, but you have enough RAM and presumably if you had any meaningful requirements beyond minimal background stuff, you would have mentioned them. The bit that you've already seemingly realised you need to re-think is the PSU. Your average mechanical drive is going to be 5-10w idle, add 50% under high load, nothing about what you've given us suggests you'll regularly see triple figures in terms of power at the wall, you want something more efficient if reasonably possible. PSU's run most efficiently under moderate load as a rule. If you want efficient, dockers and VM's usually benefit from using the cache drive (keep off the array/from spinning it up as often as possible), or having a dedicated drive passed through, remember cache pools are a thing if you want to have redundancy. The other consideration is the iGPU - if transcoding regularly under Plex then a lifetime PlexPass is the most efficient option, Jellyfin offers similar functionality for free if it'll fit your scenario.