So today we faced a situation where one level 3 opened his mouth and said virtualisation only has 5% performance loss when put against a standard OS on a physical dedicated server, so we decided to put these into some real world tests. The results are shocking to say the least. Hardware Specifications: Dell Poweredge R410 Enterprise Server Dual E5520 2.26Ghz 12GB DDR3 1066Mhz 4 x 300GB 15K SAS Drives in a RAID 10 Array. Perc6/i Hardware RAID Card with BBU Operating System Setup Setup One: ESXi 5.5 with Single instance of Ubuntu Server 13.04 with VMtools Installed (All resources assigned , 2 Processors with 8 Cores – 16 Cores total & 12GB memory) Setup Two: Bare install of Ubuntu Server 13.04 We decided to run some tests that are universally available to all readers to test this themselves so we decided to use www.serverbear.com. So lets get straight into the results UnixBench Processor Results: ESXi 5.5 with Ubuntu Server 13.04 UnixBench (w/ all processors) 3620.3 Ubuntu Server 13.04 UnixBench (w/ all processors) 5316.9 We are seeing almost a 32% drop in processor performance which left a few jaws dropped! I/O Results using IOPING: ESXi 5.5 with Ubuntu Server 13.04 I/O Seek Test (No Cache) – 7420 iops, 29.0 mb/s I/O Reads – Sequential – 1825 iops, 456.3 mb/s I/O Reads – Cached – 370452 iops, 1447.1 mb/s Ubuntu Server 13.04 I/O Seek Test (No Cache) – 9520 iops, 37.2 mb/s I/O Reads – Sequential – 2286 iops, 571.6 mb/s….