This past week I purchased a lovely Dell C6100 unit on ebay, come to find out it is unable to take any official dell updates for the BIOS or BCM module. As my unit had BIOS version 1.04 (from 2009) I was unable to upgrade my CPU’s to hex-cores. After some research, I found out the reason was because my “C6100” was actually a DCS model. DCS models are re-branded or resold C6100’s that are not registered under dell. You can test for a DCS node by checking the service tag on dell’s website. If it returns not found, chances are you have a DCS model. But, after spending a while on the internet I was able to update both my BIOS and BCM firmwares to the latest dell releases!
How To: Update a Dell C6100 DCS Node (BIOS & BCM)