Quote Originally Posted by johnw View Post
The Samsung uses a large DRAM cache (256 MiB), and so needs a larger total capacitance than the Intel 320 series which has only a small DRAM cache (64 MiB) and so does not need as much capacitance to power the board until the cache can be flushed to flash. Also, I suspect the Samsung's controller uses more power than the Intel 320 SSD's controller.

Note that SR uses the term "ultra capacitor" to refer to the capacitors in the SM825. That means the same thing as "super capacitor" -- they are both names for an electric double layer capacitor.

Anyway, you can bet that the 4 capacitors on the Samsung SM825 board have a lot higher total capacitance than the 6 capacitors on the Intel 320 board, and they surely cost a lot more, too.
Anandtech says the Intel 320 Series does not store user data into the DRAM cache, but instead, in the SRAM cache. Anyway, the capacitors may be responsible for the safety of the FTL table or whatever mapping tables working in the DRAM cache.

I can confirm that the Samsung 830's controller uses A LOT MORE power than the Intel 320 Series', when bombing them with 1QD 4k random write full span. The temperature difference is very easy to tell!