Well, with the jagged edges comes a long render time, however you might have some things on that you dont in your render settings. Below are my Settings (Aside from Output + Save tab, you can figure that out
)
Checked Settings:
http://gyazo.com/68f1ea6eb4d8c5fb39ff82cea2c7d57e
As you can probably see, Global illumination and Ambient occlusion are off, this WILL require editing, or adding more softboxes to accommodate. If you would prefer to have GI + Ambient on, here are my settings.
Ambient:
http://gyazo.com/6b9ec3105c95b59ef13263620607b1f5
GI:
http://gyazo.com/0020d8f5d37a175fa14a5327ba61e1a9
Irradiance Cache (GI):
http://gyazo.com/48f3f1a337a9f5a9c0b862ee4d40baa6
I get about 20 second renders on really High Poly Count renders. WITHOUT Ambient + GI, that end up looking really nice. Some things just need it though. Those renders take just under a minute for me.
Also, try going into your preferences Edit> Prefferences and go to "Render" My Settings:
http://gyazo.com/f4df49736ba492e317a6afed41bad995
You can also edit the amount of CPU allowed. Dont go overboard unless your PC can handle it