4kio KVM testing on Ubuntu 16.04 via the Phoronix Test Suite. 4k_io_subsystem: Processor: Intel Core (4 Cores / 8 Threads), Motherboard: Red Hat KVM (0.5.1 BIOS), Chipset: Intel 440FX 82441FX PMC, Memory: 1 x 8192 MB RAM, Disk: 189GB, Graphics: Red Hat QXL paravirtual graphic card, Network: Red Hat Virtio device OS: Ubuntu 16.04, Kernel: 4.4.0-142-generic (x86_64), Compiler: GCC 5.4.0 20160609, File-System: ext4, Screen Resolution: 1024x768, System Layer: KVM Intel Core - Red Hat QXL paravirtual graphic card -: Processor: Intel Core (4 Cores / 8 Threads), Motherboard: Red Hat KVM (0.5.1 BIOS), Chipset: Intel 440FX 82441FX PMC, Memory: 1 x 8192 MB RAM, Disk: 189GB, Graphics: Red Hat QXL paravirtual graphic card, Network: Red Hat Virtio device OS: Ubuntu 16.04, Kernel: 4.4.0-142-generic (x86_64), Compiler: GCC 5.4.0 20160609, File-System: ext4, Screen Resolution: 1024x768, System Layer: KVM Flexible IO Tester 3.1 Type: Random Write - IO Engine: Sync - Buffered: No - Direct: No - Block Size: 4KB - Disk Target: Default Test Directory MB/s > Higher Is Better 4k_io_subsystem . 22.63 |====================================================== Flexible IO Tester 3.1 Type: Random Write - IO Engine: Sync - Buffered: No - Direct: Yes - Block Size: 4KB - Disk Target: Default Test Directory MB/s > Higher Is Better Intel Core - Red Hat QXL paravirtual graphic card - . 3.09 |===================