iCloud Photo Library - Initial upload/storage very high

[revs]

I've finally decided to start uploading all my photos to iCloud Photo Library as I have a few devices and want to sync.

I am however getting a little concerned as I have a ~160GB library, with approx 20,000 items.
45 items have uploaded so far, and supposedly used over 1GB of space, double what it should be using.

Has anyone else seen this on the initial upload? I'm assuming it's maybe uploaded more than it says it has, and its taking a while to update/process so the item count and storage 'match'

 

[T'hain Esh Kelch]

Likely as part of the initial upload, an index file of your entire library is created, which takes up quite some space. I wouldn't be worried.

 

[revs]

Update: I've let it continue and it seems that it's eventually sorting itself out. The cloud storage use is now only about 3GB higher than expected (16GB remote, 13GB local). With 100+GB to go, so fingers crossed.