Why is my library 200+GB bigger after importing from Iphoto to Aperture

Why did you import the Library to Aperture? There's no need. Aperture can open the Library. Now it's an Aperture Library.

If that Library has only 9,200 items and weighs in at 687GB there is something wrong there.

Your library is big, but nothing out of the ordinary and well within Apertures capabilities.

It's hard to say definitively why the library has grown so, but ultimately it won't matter, once you have your library working well and you configure Aperture how you want it to operate, and you tidy up any unwated artefacts from the import, your library size will become exactly the size it needs to be.

There are a number of possible explanations for why things are going slow.

First, check how you have formatted your Drobo storage. The file system requirements for Aperture are described here:

http://support.apple.com/kb/ts3252

Next, having chosen to import your iPhoto Library, you have essentially created a new environmet with its own preferences controlling things like previes, faces, places and so on. These could explain both the size and any (temporary) performance issues.

With Aperture running, press SHIFT+CMD+0 (zero). This will show you the activity window so you can see if Aperture is performing any follow-up tasks relating to the import such as building previews, building thumbnails, detecting faces and son on.

If so, allow it time to finish. Once it's finished all the post import activity, it will settle down and begin to operate in a more optimised fashion.

Depending on the history of you old iPhoto library, there could be some clean-up work do in terms of edited copies of originals. Old versions of iTunes used distructive edits, meaning you got an edited copy of your original. Aperture doesn't work this way and you will need to decide if you want to keep those (for example stack them with tier orginals) or if you want to redo any of them using Apertures non-destrutive tools. Later versions of iPhoto used a similar non-destructive approach which will carry over, so it's just any very old edits you may have to make descisions for.

IAndy

How can I check the preferences for importing? maybe it is generating big size previews? would that affect on the size on the library?

In the Aperture Preferences panel, in the "Previews" tab.

Set the "Preview" size in the "Photos Preview" pop-up menu. And select a quality value.

If you do not want to create previews by default, disable "New projects automatically create previews".

If you do not want the preview processes running in the background while you are working, hold down the "Shift" key while you are launching Aperture. That will defer the generation till the next lauch and you can let it run over night.

I keep it usually set to 10. But check, if you are happpy with 8. With 8 or less you may be noticing some jpeg artefacts, when you are using your Aperture previews for fullscreen viewing as screensaver or Desktop picture.

You can also delete the previews for selected images. I keep only previews for selected images that I need to share with other applications, i.e. all images that I have have rated with four or five stars.

To delete Previews, select the photos and use the command "Photos > Delete Previews".

If you reduce the jpeg size and quality, use the same menu to update the preview. Select your photos, go to the "Photos" menu, hold down the options key ⌥, until "update Preview" turns into "Generate Preview". That will recreate them.