I have recently downloaded WPMU Dev and Hummingbird for some help on my 8th grade project, I am 13 and relatively new to Wordpress, so I want to get a great experience out of it. To whom it may apply: my problem is that the WPMU Dev Dashboard plugin and Hummingbird increase my server response time to an alarming number, such as the once seen in the screen shot. Occasionally, it fluctuates and goes back to quick response time, but I don't want it to happen again. Is there anything that could be wrong with my site, that might be affecting the performance impact of my plugins?
PS: I have to grant admin access, right?