Sorry if this is a noob question (this isn't my normal area) but I need to check something and my Google-fu is failing me.
I have a software build machine (not a VM) running Windows Server 2012 R2 Standard that recently started performing very slowly. (A normal build usually completes in under 30 minutes but was now aborting after 5.5 hours. And the server itself would sometimes momentarily disappear off of the network.) Logging in, I noticed in Task Manager that the CPU (Intel Xeon CPU E5-1410 0 @ 2.8GHz) had a constant speed of 0.14GHz while the utilization bounced between 1-5% (memory was at 20% and there was plenty of free space on the C drive). This situation lasted four days and then improved by itself. It now has a constant speed of 1.18GHz while the utilization occasional peaks to 30%.
My IT guys are from an outsourced company and say the slow down was due to SQL Server on this machine (even though we only use this instance as part of the build process and we stopped all jobs). They say there is nothing wrong.
(a) Does the explanation make sense?
(b) Why doesn't Task Manager (on a non-VM) report the speed at 2.8GHz?
(c) Should I be worried?