Same issues here, i guess EA is claiming it's being caused by a massive flood of players to the nine servers that sim city currently has support for. Makes sense considering players who preordered couldn't play it last night at midnight, due to frickin origin, so they went to bed and a few stayed up all night and got to know what the game should be kind of like. Overall very buggie for a release and nine servers for thousands of players.... get it together EA.
My specs:
AMD FX - 4100 3,6Ghz
8 GB RAM
RADEON HD 7970