On Thursday, June 8, 2017 at 6:48:57 AM UTC+2, mojosam wrote: > I'm thinking about replacing one of my computers. I don't know if that will > be my Qubes machine or one of the others. I talked to the owner of the local > mom & pop computer shop. I said that I was considering getting an AMD > processor, because they have a lot of cores. He said that most applications > don't take advantage of more than four cores. I said that I want to run a > lot of VMs. He said even there it didn't matter much. > > I'm guessing that he might be thinking of type 2 hypervisors, which are > basically just another application running on Windows. I had assumed that a > type 1 hypervisor such as Xen with Qubes would be different. > > Does anybody know if that is true? If I buy a computer with 8 cores and set > up a VM to use 2 virtual CPUs, does Qubes assign 2 cores to it? > > If I have 3 VMs, each crunching intense numbers, does Qubes give them two > cores each? (That leaves the other 2 cores for running the OS.) > > Or is this naive, because CPUs and OSes are complex things and don't work > that simplistically? > > Or to simplify, assuming that an Intel CPU with 4 cores is roughly equivalent > to an AMD CPU with 8 cores, would Qubes with a lot of open & busy VMs run a > lot faster on the AMD machine?
The number of cores allocated in Qubes is the maximum that single VM will use, if it has less to do, it'll just use fewer; so it's perfectly fine to allocate cores to more than one VM. I have a Ryzen 1600, with 4 threads assigned to most VMs, 8 to some, and 10 to my dev VM for compilation. Works fine that way. But if you intend to constantly run 3 concurrent CPU intensive tasks/VMs, it may make sense to assign them slightly more conservatively. Leaving aside overclocking, in terms of total compute performance the 1600x (6c/12t) is the equal of the i7-7700k (4c/8t, higher IPC + clock speed) -> http://techreport.com/review/31979/amd-ryzen-5-cpus-reviewed-part-two/3 the 1500x (4c/8t) is superior to the i5-7500 (4c/4t), and the 1600 far superior to the i5-7600k (4c/4t) (https://www.youtube.com/watch?v=MgHnLu6k0D4 ). And due to the availability of the extra cores & threads, everything runs a lot smoother. But yeah, it'll definitely also be faster at the same price point. Only issues atm are iommu support (which is there, but unpolished and still being worked on -- related to grouping/isolation), and doesn't fully work in Qubes 3.2), plus some other usual teething issues associated with the launch of a new platform (support for high speed memory, for instance). -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/bbde67d1-3088-4136-a5db-12ce9a5e2bba%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
