using LiveJob and the cpu has 100%

Question

when i use LiveJob and  as  following setting :

 Job.OutputFormat.VideoProfile = new Microsoft.Expression.Encoder.Profiles.MainVC1VideoProfile
            {
                InLoopFilter = false,
                MotionSearchRange = Microsoft.Expression.Encoder.Profiles.MotionSearchRange.MacroblockAdaptive,
                Size = new System.Drawing.Size(monitorSize.Width, monitorSize.Height),
            };

the cpu has 100%,can you give me some changes?