I'm thinking about installing extra videocards for GPU mining on a LAMP server that I actually use for developing and/or cronjob events (such as backups and similar), so I'd like to ask if this setup might affect also CPU time while mining or the CPU will still remain generally unaffected for its normal operations.
With ATI GPU, your CPU is used heavily during the dag creation phase but after that, there's almost no impact on CPU except the whole computer heat generated. Also disk access and network are lightly used during mining. I think you just should try and see it by yourself but if your computer is well cooled, you should be ok.
In some cases (unfortunately many), the processors in Windows 10 show 100% usage. From what I understand the problem grows according to the number of GPUs. Windows 10 overloads processors that have few flames when GPUs are more than the threads.
After many tests on different systems, I'm happy to let you know that the increased workload of the processor is due solely to the operating system (Windows 10).
I found some tweaks for windows 10 and achieve more than 50% less CPU usage.
New CPU Usage: 45%
Have a nice mining!