Can anyone tell me what PC will draw more power?
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.
I do not agree with that.
A PSU is the maximum what all the components combined are allowed to use. No more power than that is possible. If a system needs more than it's PSU can deliver, it will become unstable (data loss, random restarts, etc.)
The 2x750 is a redundant setup that servers have. Servers need to be able to run 24/7. With redundant PSU if one PSU has a failure, the other PSU will take over. Without any restarts. You can just pull the plug out of one of the PSU and all is just fine.
I do agree with you that the max wattage is under load. Most home servers are running idle most of the time anyway.
that's why there's 2x 750's instead of a single 1500 watt, yes. but they're frequently capable of drawing more than the 750 watts under high demand loads. which is kinda why I put that bit in parenthesis. The OP has said they have it unplugged.
first point is literally what I said.