3 Replies Latest reply on Aug 15, 2018 10:23 AM by AveryFreeman

    New host build, very slow VM performance

    AveryFreeman Novice



      I have a new build I just put together and am running ESXi 6.7 + vSphere 6.7 - just updated ESXi with latest updates from https://esxi-patches.v-front.de/ESXi-6.7.0.html


      The system is performing extremely slow.  I am making my first VM, Windows 10 1803, and the speed reported in vCenter is 600 MHz.  And it really feels like it, too.


      My system:

      Supermicro X10SRL-F motherboard latest bios (3.1)

      E5-2650 v4

      2 x 8GB DDR4-2666MHz RAM 1rx8

      Samsung SM953 NVMe datastore

      running off USB to boot


      I'm noticing as I write this that I am only using 2 DIMMs in a system with 4-channel memory.  I have more memory coming soon, so hopefully that will improve things.


      But it's hard for me to believe this is all because of using two DIMMs instead of four.  Is there some sort of setting maybe in the VM or in vSphere that can be tweaked when the processor is clocking so slow?


      Thank you


        • 1. Re: New host build, very slow VM performance
          mulcas Novice

          Hi Avery,


          Few questions:

          • What do you mean by the VM is reporting a speed of 600 MHz?
          • What applications do you want to run in this VM?
          • Do you installed VMware tools?
          • What kind of performance are you expecting from this VM? (IOPS? Throughput Latency?)




          • 2. Re: New host build, very slow VM performance
            AveryFreeman Novice

            Hello, and thanks for your reply


            I am seeing vSphere report the MHz in the Hosts and VMs section under the VM--> Configure page - you know, where it has the 'play' button and the link to open Workstation to view the console.


            I am actually working on using this as a desktop with GPU passthrough.  I had a Nvidia 740 GT working with passthrough for a while but it appears to have stopped working, but that's for another thread.


            Yes, vmware tools is installed because I am using paravirtualized drivers for SCSI and NIC.  I load the drivers for pvscsi during installation and then install vmware tools 64-bit immediately on first boot for vmxnet3.


            Just noticed when I was making the VM that it is ungodly slow.  Had never noticed a MHz report in vSphere before, but there it was.  I know resource utilization is extremely low as per esxtop and meters in vSphere - but a 4-core VM should be able to operate Windows in a plenty snappy way.


            So far now I've tried turning off P and C states in the BIOS and it appears to subjectively made things a little faster.  The processor has a base freq of 2.0GHz but it's 2.7GHz  turbo so I'd think it'd be capable of being at least mildly peppy.


            I am going to see if I can find a reference for common BIOS settings to enable for ESXi hosts.  It's my first E5 motherboard, there's a lot of additional settings I don't recognize having only worked with E3s.


            Another thread I was reading was talking about virtual machine monitor mode, which turned up this KB article:  VMware Knowledge Base


            However, I don't see that setting in my version of vSphere.  I tried setting

            monitor.virtual_exec = hardware

            monitor.virtual_mmu = hardware


            manually in the VMX file (through edit -> vm options -> advanced settings).  But I do not see any difference from that.


            Any thoughts? Thanks

            • 3. Re: New host build, very slow VM performance
              AveryFreeman Novice

              OK, I figured out the problem


              I had accidentally set the datastore location as an NFS datastore.  Major oversight on my part.


              Anyway, I'm glad to know there isn't anything terribly wrong with my new host - just some serious user error.  Pretty tired from all the time I've put into this thing over the last few days and now making dumb mistakes!