Qube Limit

[solene]

@Raist

i5-8350 (8 Threads x 4 Cores) x 1 Physical CPU = 32 vCPU

No, you have 8 threads, which is a bit less than 8 vCPU.

Your CPU has 4 cores, all featuring hyper-threading allowing them to run 2 operation at the same time instead of one, under certain conditions. By default, hyper threading is disabled in Qubes OS because it leads to security issues as it’s been proven that it’s possible to leak data when SMT (the real name for the hyper threading technology) is being used.

It’s possible to enable SMT again if you really want to.

@Raist

Is there a an actual coded limit in Qubes OS for how many Qube VMs you can create in the manager? Ex. you hit 99 Qubes and it won’t let you create anymore? I was actually kind of surprised I couldn’t find someone who asked that yet.

maybe 254 or half of it as a qube has 2 disks 5.3. Xen limitations Red Hat Enterprise Linux 5 | Red Hat Customer Portal

@Raist

Is there any software or hardware limits for how many Qubes you can run at once? Obviously performance will keep decreasing as you start more Qubes and of course there’s a limit of what you can run on any device.

memory will limit you. You can over provision the CPU by running 12 qubes with 2 vCPU each on a 4 cores system, it’s fine as long as they idle, but they will all use some reserved memory.

@Raist

if the answer to question 2 is that you can open any many as you want and performance will just continue to decline is there anyway to determine a guesstimate of how many your machine can run at the same time that is optimal for the resources available or is there just to many variable like whats is going to be running in the qube etc. so it’s trial and error.

It depends on what you do, if you use a web browser, you will certainly need 3 or 4 vCPU to be good, if you only have 4 cores at all, the more you keep the qubes running, the less you will have for the “big” usage.

There are no rules for allocating resources. If the qubes are idle and you don’t need a qube with all the CPUs, that should be fine to over provision. It’s still possible to pause a qube when you don’t need it, so it’s still using the memory but won’t use any CPU at all until you unpause it.