I have been using Wowza for around a year now.
It started off on a 3 year old server core i5-2400 3.1ghz (CPU score 5821) running as a virtual machine and I could run 1 instance or Transcoder and the CPU would hover around 40%.
On another VM I was renting it would hover around 40% with 1 instance of transcode.
As I am purchasing more 1080p Axis cameras I have upgraded to a new Dell poweredge with a XEON E3-1271 v3 3.6Ghz (CPU score 10304) and I am running on the host operating system and 1 transcode instance keeps the CPU in Wowza running at 80-90%.
I thought upgrading to 4.2 would have included fixes for the latest CPU's but it seems even more intensive.
Please help as it seems the more powerful server I purchase, the more CPU is used.