The dvds of this "Artificial Eye" do not have six ninety minutes episodes as you say. Their length is as follows, including about twenty seconds of credits in the beginning(with sound of the story) and about one minute in the end (with sound and image of the story). I am rounding down the time,excluding the seconds so they all last a tiny longer than the time presented here:
dvd episode one 1h 41 min or 101 minutes, not 90.
dvd episode two 1h 35 min or 95 minutes
dvd episode three 1h 59 min or 119 minutes
dvd episode four 2h 06 min or 126 minutes
dvd episode five 1h 40 min or 100 minutes
dvd episode six 1 h 50 min or 110 minutes
Total : 651 minutes or ten hours and 51 minutes. The time goes up to about 654 minutes after adding about 3 min that were excluded in the rounding down .
So this dvd version is 35 minutes shorter than the director's cut version , which had 689 minutes ( "The Guardian" and "The Independent" say 680 minutes but IMDb says 689. I am using IMDb's time just to use the worse case scenario )
Each episode of this "Artificial Eye" set is less than 6 minutes shorter than the director's cut. Edgar Reitz wanted to do an eleven episodes Heimat 3 but the German TV agreed with only six episodes and he was forced to film a much shorter Heimat 3 than the one he wanted to do.
The dvd set from Artificial Eye, that I have right in front of me
The Guardian ( argh!) online 04 may 2005 http://www.theguardian.com/media/2005/may
The Independent online 08 may 2005 http://www.independent.co.uk/arts-enterta
P.S. The product description on Amazon gives a running time of 750 minutes, which is a close approximation of the total running time because they included the extra features from dvd one in the running time: a 58 minutes documentary and a 32 minutes interview with Edgar Reitz.