VM Running Poorly with MPI
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I have a Ubuntu virtual machine that is used to do some scientific computing with MPI. The VM has 64 vCPU and 200GB of memory. When compared to running the same code on a physical workstation with half the CPU cores and half the memory, the jobs run 10x slower on the VM vs the workstation. The VM is running XenTools and is recognized in XOA.
Below is the lscpu output for both:
Workstation:
Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Address sizes: 46 bits physical, 48 bits virtual Byte Order: Little Endian CPU(s): 36 On-line CPU(s) list: 0-35 Vendor ID: GenuineIntel Model name: Intel(R) Xeon(R) W-2195 CPU @ 2.30GHz CPU family: 6 Model: 85 Thread(s) per core: 2 Core(s) per socket: 18 Socket(s): 1 Stepping: 4 CPU max MHz: 4300.0000 CPU min MHz: 1000.0000 BogoMIPS: 4599.93 Virtualization features: Virtualization: VT-x Caches (sum of all): L1d: 576 KiB (18 instances) L1i: 576 KiB (18 instances) L2: 18 MiB (18 instances) L3: 24.8 MiB (1 instance) NUMA: NUMA node(s): 1 NUMA node0 CPU(s): 0-35Ubuntu XCP-ng VM:
Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 46 bits physical, 48 bits virtual CPU(s): 64 On-line CPU(s) list: 0-63 Thread(s) per core: 1 Core(s) per socket: 64 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 85 Model name: Intel(R) Xeon(R) Gold 6242 CPU @ 2.80GHz Stepping: 7 CPU MHz: 2793.534 BogoMIPS: 5587.06 Hypervisor vendor: Xen Virtualization type: full L1d cache: 2 MiB L1i cache: 2 MiB L2 cache: 64 MiB L3 cache: 1.4 GiB NUMA node0 CPU(s): 0-63What could be the cause of this? And what's the resolution?
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I would start to check the power settings (if the CPU is boosting correctly in the VM).
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@olivierlambert There are no performance options available in the Ubuntu VM (running 20.04). Am I missing something to check/change for cpu performance?
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I'm talking in the BIOS or in Xen, I would stat to be sure that the CPU is boosting
