For PS2, it doesn't really matter, as it doesn't use a lot of bandwidth. What's really important is latency and jitter. Latency itself isn't so bad despite what most people think, because server-side heuristic calculations can often compensate for latency, at least in ping times less than 200 ms or so because, due to human reaction time only being about 100 ms or so, the server typically can make fairly accurate predictions, such as the fact that you're going to continue moving in a certain direction or continue turning in a certain direction. As your ping times come up outside of average human response times, the server starts running into more difficulty predicting your actions. But, keep in mind that we're talking ping times of like >150 ms here; less than 100 ms or so it's typically not a huge problem.
Jitter, or unpredictable variations in latency, will really can screw with your game, and it often comes hand-in-hand with latency. With jitter, you might have 30 ms latency one moment, and over 100 the next. This can throw the server's heuristic calculations out of whack and it's usually caused by very bursty traffic on your network or problems on your ISP's network.
TL;DR - Use pingtest.net instead of speedtest.net to determine if your game is suffering due to ping times.
|