With the first quarter of 2011 closing up, we’re getting a first look at how social networks have been performing since the end of 2010. Facebook is at the head of the pack when it comes to website response time, a position it has held for the past 5 quarters, according to AlertSite. However, YouTube reigns supreme in terms of website availability.

Facebook’s speed increased from 1.06 seconds in Q4 of 2010 to the new level of 0.75 seconds. That’s quite the improvement for a network with 665 million users. YouTube comes in second with a response time of 1.46 seconds with LinkedIn coming in third at 1.69 seconds. These all remained above the industry average of 2.42.

YouTube can boast being the most reliable social network on the Web, being available 99.96 percent of the time, which is pretty impressive for a site that handles 35 hours of video every minute. LinkedIn comes in at a close second at 99.91 percent availability, which is in turn just ahead of Facebook at 99.88 percent. All of these are a good level higher than the industry average of 99.77 percent overall.

Both Twitter and Myspace trailed behind their competitors and even the industry average in both of these categories. Twitter sees 99.64 percent availability with a response time of 2.59 seconds. To its credit, Twitter has remained consistently fast and responsive despite its growing user base. Myspace trails behind all of these, available 99.44 percent of the time while possessing a much longer response time at 5.60 seconds. Ouch.

The data represents performance from January 1 through March 31 taken from 12 monitoring locations in the U.S. testing every five minutes between 6 a.m. and 11:59 p.m. EST.