Speeding up rendering on simple composite

[pjkw]

Hi, Im conforming a 1h 30minute long clip and I need some ideas what I can do to speed up the export.
Its basicly just a conform with some images with alpha on top, most of the images have dissolves.
Doing a testrender, the pre-export render says its gonna take 20 hours.
Im currently using prores 4444 as my cache format, will 422 be significally faster? Or is there some way I can make it render straight to files as opposed to first rendering to prores? I have no real need for playback for this I just need to get it out faster. I know prerendering effects will save time for final export but I will get the final conform very late so theres no time for that.
Any help appreciated

[BKM]

A couple of things will affect export time.

If nothing is rendered on the timeline then it should render everything before it exports.  When it's done, it will then export.

What is your source footage? Prores? h264?  And how fast of a drive are the source files on?  
And are you reading and writing to the same drive.... is your export going to the same drive as your source files?