My Dell Vostro has space for two drives, but I have never been motivated to order the special adapter from Dell. Probably costs more than a 500GB drive. The Disk Management utility offers a "spanned volume" choice to make two drives look like a single drive--but I have never used it.
I like my partitions. Lately, (last ten years or so) I have always bought my computers with a small hard drive, at the same time I bought an extra, larger internal replacement. Then first thing out of the box, swap drives and install the OS etc on the new drive. If I ever sell the computer, the old drive goes back in. until Vista, I always formatted 3 partitions, OS/Software, Data, Temp. When the defragging on the fly feature showed up, I stopped making the temp partition.
Back a ways, I lost a HD, and everything on it. Cant remember the years, but it was a 20MB HD.
After that I got backup-fever, and the data partition just makes it easier.