6 Replies Latest reply on Aug 27, 2013 11:13 PM by marc.ceeeee

    Regarding the DC S3700 SSD capacitors + write cache

    marc.ceeeee

      Hello,

       

      I have a question about the capacitors in the DC S3700 and the DRAM cache. In the event of a power loss while write caching is enabled on the device, do _all_ of the cached/buffered writes make it to the NAND? Or, are the capacitors there to ensure that any active writes at the NAND are written atomically (and prevent corrupting data/metadata/tables/etc)?

       

      I was curious because depending on the answer, I'll turn write caching on or off in our server setup, or purchase the battery-backed option for our RAID card.

       

      I don't see such information in the product data sheet, yet some press releases and reviews imply the first option to be the case.

       

      Thank you!

       

      edit 1:

      I found this verbiage on ARK:

       

      Enhanced Power Loss Data Protection prepares the SSD for unexpected system power loss by minimizing data in transition in temporary buffers, and uses on-board power-loss protection capacitance to provide enough energy for the SSD firmware to move data from the transfer buffer and other temporary buffers to the NAND, thus protecting system and user data.

       

      Is there a less-fluffy statement that can affirm that all buffered writes will get to the NAND atomically? (i.e. All commands which have been acknowledged by the SSD with 50h/00h status while write cache is ON will be written on power-loss).