It appears the CPU boost support on KVM doesn't handle Windows VM, hence the lower numbers on a Windows VM vs a Ubuntu VM.
PassMark – Single Threading measurement, the majority of Perf Score are relied on vCPU Clock Speed. Is this a know limitation? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2045425 Title: Windows VM slower performance with Passmark vs Ubuntu VM Status in linux package in Ubuntu: New Bug description: Summary : A Windows VM(KVM) on 22.04.3 is 10%(SMT off) to 16%(SMT on) slower running Passmark vs a Ubuntu 22.04.3 VM(KVM). The results should be within 1% of each other. System Information : Dell - AMD EPYC 7543 32-Core Processor, 2801 Mhz, 32 Core(s), 32 Logical Processor(s) Zen 3 (Milan) BIOS - 2.12.4 FW (iDRAC Firmware Version 7.00.30.00) NUMA Nodes Per Socket 1(default) Memory - 512 GB of DRAM DDR4 OS : Ubuntu 22.04.3 Setup: Install Ubuntu 22.04.3 and then setup 2 VMs one with Win 22 std. and another one with Ubuntu 22.04.3. Install Passmark benchmark on both the VMs and then run the “Single CPU Threaded” benchmark on both the OS with SMT enable and disable mode. Passmark Download link : https://www.passmark.com/products/pt_linux/download.php Linux Setup version: PerformanceTest Linux x86 64-bit 5.4 MB, v11.0 Build 1002, October 19 2023 Microsoft setup version: Download PerformanceTest 11.0 x86 102 MB, Build 1007 For Intel and AMD x86 CPUs Results : *********** Bare metal *********** Windows 2022 ------------ SMT ON: Win22 VM 1% slower SMT OFF: Win22 VM 1% slower SMT Run1 Run2 Run3 Average On 2766 2768 2771 2768.333333 OFF 2773 2766 2765 2768 Ubuntu 22.04 ------------ SMT Run1 Run2 Run3 Average On 2777 2777 2775 2776.333333 OFF 2798 2792 2792 2794 -------------------------------------------- **** KVM **** SMT ON : Win22 VM 16% slower SMT OFF: Win22 VM 10% slower Host: Ubuntu 22.04 VM: Win server 22 VM - Single CPU Threaded SMT Run1 Run2 Run3 AVERAGE On 2356 2287 2289 2310.666667 OFF 2424 2459 2566 2483 Host Ubuntu 22.04 KVM with Ubuntu 22.04 VM - Single CPU Threaded SMT Run1 Run2 Run3 AVERAGE On 2730 2741 2729 2733.333333 OFF 2745 2746 2746 2745.666667 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2045425/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
