Tales of Symphonia not running fullspeed

[Shonumi]

When was the first time you ran Tales of Symphonia in Dolphin? That is to say, which revision at the time were you using? Your CPU is pretty underpowered for Dolphin; it may be the case that newer revisions are simply more demanding than the revision you previously used. You can go back to whatever revision you were using beforehand, just note that revisions prior to the 4.0 release are not supported any more.