How many cores do you really want for an XCP-NG home lab that will have a couple of VM’s “running” all the time?
I’ve been fooling with old X56xx series Xeons and have enough in my hot and loud machines at work to have 24 “cores” per host with 72GB of ram per host. I want to build something quiet and lower heat for home and before I buy more low power computers, I thought I should probably take the time to wrap my head around processor and ram provisioning in XCP-NG.
At work I’ve been building VM’s with 8 “cores” and 8GB of ram (hard maximums) to give me decent performance, but is this being wasteful? This would limit me to around 2 to 3 VM’s per machine without going too deep into over-provisioning. And certainly crunch things when I need to move VM’s to apply patches and reboot, etc.
What I’m really wondering is if I could get away with a few AMD 8c/16t (or smaller) computers, assuming I can pack a decent amount of RAM inside without costing too much. I mention AMD not because I’m a fan boy, but because I can get more cores per dollar (typically). Would 4c/8t or even 4c/4t really be enough for a domain controller (probably Zentyal), a couple Windows Server evals., and a couple Linux machines (per host)?
Decent low power computers can be had with 4c/4t and 8GB for around $200 each. An 8c16t computer with 64gb+ of ram is probably going to be close to $1000 each (new prices). I need to weigh not only cost/performance benefit but heat/power/noise, the last set stops me from just buying old servers and building a system on the cheap like I have stored at work (or bringing the system at work back home).
I’m currently doing things at home on Atom D525 and a couple dual core Celeron, the Celeron at least have 8GB where the Atoms are limit to 4GB and the Atoms run a bit hot since they tend to run above 50% processor all day long.