Yes, Using the atmospheres will really slow things down.

Firefly doesn't really care much about your video card, but System RAM and CPU Speed are critical...

On the Render Settings page, if you click Acquire from Auto, the settings on the auto page will be transferred to the Manual page. The Settings in your screen shot are the defaults, so you can really drag this render out by using these settings (which are similar to what I use on a final render)

This render, at those settings, too a little less than half an hour... the original image size was 1477 x 808, before I cropped it....

I'm using an ASUS gaming rig with In I7 & 24 GB o' RAM

I hope this helps!!

;>

Andy!