This is probably a stupid question, since 2 > 1, but here goes…
I have a home server. It’s a ComputerLINK 1U rack server I bought off eBay some years back. It has 2 CPUs, Intel Xeon E5645 2.4Ghz(https://ark.intel.com/content/www/us/en/ark/products/48768/intel-xeon-processor-e5645-12m-cache-2-40-ghz-5-86-gt-s-intel-qpi.html). It also has two 750W power supplies, but I have one unplugged. It also has RAM and 5 HDDs.
I also have the guts of my old desktop PC. The CPU is an AMD FX8350 4Ghz(https://www.amd.com/en/products/cpu/fx-8350). The motherboard is some ASUS model, I forget and don’t want to check right now. A potential PSU would be 500-600W range.
My question: I am considering moving to use my old PC parts as a new home server. One benefit is to cut down on the noise (rack mount PC fans are LOUD). But the real gain I would want is on power savings. So, if RAM and the multiple HDDs all stay the same, but I moved them to the AMD/ASUS CPU/motherboard, can anyone definitively say this will be more power-efficient?
I am not very knowledgeable when it comes to electrics or power consumption, and am just looking for someone to confirm for me. I am aware that the AMD CPU still isn’t an excellent choice for an always-on machine, but it could be an improvement.
Why not check online for each component for its max watt?
AMD FX8350 is 125W max Xeon E5645 is 80W max
Then the only difference is the motherboard, right?
And also, the Xeon has integrated graphics but the amd does not. If you will let the amd do a lot of things with video, it needs a video card or else the cpu will need to do all of that. On the other hand, if the machine main task is to for example render videos, an integrated GPU in the Cpu will not get you far either…
It depends on the application/duty, but maximum/rated power is not usually relevant for power consumption on home servers like this - they’re rarely running at mother than a few percent load.
Idle power consumption is the main concern. Server boards often have a lot of NICs and chipsets that don’t idle well. Consumer gear is generally much better for that.
Neither Westmere nor the AM3 platform are known for low power consumption. A modern LGA1150 or later desktop platform would probably be preferable.
I don’t know how much that 8350 uses at idle, but that cpu is really old now and certainly not known for being power efficiënt. Honestly I think you’re better off getting something more modern, if you buy used it doesn’t have to be expensive either.
Why not plug each into a Kill-A-Watt and measure it at idle and under load?
You are right that this is the true way to tell, but I don’t own one, and the “new” PC is not set up at all. I would have to tear apart the old and build the new to be able to test the new one.
Question: does your home server Need to be powerful for what it does? Would a mini desktop PC or a single board computer be able to do the same job as your current setup? Of your main concern is truly power savings, consider those options. Most mini pcs maybe draw 60 watts, most laptops only draw around 15-20 watts, most SBCs only draw around 5-10 watts max with the raspberry pis exactly 5 watts max. The zero SBCs draw one watt of power at max and consume half a watt idle.
The best way to increase energy savings on your currently owned server would be to upgrade your PSU and not motherboard. Get a gold rated PSU certified by energy star as it has at least 85% efficiency. Invest in a kill-a-watt measurement device that plugs into the outlet so you an see exactly how much wattage you are pulling and how much you manage to cut down.
There are probably Mini PCs that would work for my load, but those would be higher end ones and I am not looking to spend money.
I run a lot on this machine. Nextcloud, Jellyfin, Home Assistant, TVHeadEnd, Mosquitto, Z2Mqtt, databases, file shares, pacman cache, a lot more that I am forgetting. Basically lots of IO going on at any point.
