Title says it all I only get 2.5 MBS transfer with my Mini 10v Hackintosh

I bought this off a Hi-Fi Fourm Admin already hacked and was wondering if 2.5 MBS is the best x-fer rate I can get?

It has a 2MB memory and 7200 RPM HHD ugrade but I think everything else is stock...

Is there something I need to change or check???

My Router is Linksys G54 / DD-WART and I get x-fers to other boxes at 100MBS

Thanks Much