New Photo app - upload speed to iCloud photos really so slow?

I installed the new Photos app and imported my Aperture library (about 50.000 photos altogether. As I had a bad experience when my hdd with my pictures was stolen, I want to upload all of them to iCloud. (I am not a professional photographer)

So far so good: but in the last three days, only about 5000 photos were uploaded. In other words: 30 days to go...

Is this to be expected?

Does anybody has any experiences with uploading that many photos?

I am obviously uploading via ethernet (1000 baseT) and the internet connection is not nearly saturated.

Just realized, it is on my side and my upload is saturated since I installed Photos - so it is not Apple's fault:

If I am not mistaken, it should be done in about 12-15 days.

Looking at my speeds it appears that Apple presently is limiting it. I have 1/2 a gig of upload speed but i'm showing about 200 gig going up and I have not limited by upload speed at all. When doing an icloud backup from an iOS device it uses ALL the bandwidth and that slows other devices on the network and often disrupts connections so I think this may be intentional to throttle the upload of photos. I have 50K pictures as well and I've been at it for several weeks with very little progress.