Click on the apple logo in the top left corner, select about this mac, click the "more info" button, click the "system report" button. In there the Graphics/Displays section will have what you want model numbers starting with SM are samsung. For the SSD go the the SATA/SATA Express section same model designation.
I swore that the 128GB SSD was only manufactured by Sandisk? And the 256GB/512GB was Samsung (all I've seen is this) or Toshiba. Just download Blackmagic Disk Speed Test app from the Mac App Store and see what numbers you get. All the mid - late 2013 reports I've seen are 700+ for reads and writes and a staggering 1000 MB/s + for the 1TB SSD (only available in the rMBP).