The SSD guy usually argues that NAND flash (as an SSD) fits into the memory/storage hierarchy for two reasons:
- SSDs are cheaper than DRAM but more expensive than an HDD
- SSDs are slower than DRAM but faster than an HDD
An SSD is usually a very good alternative to adding more DRAM to a system, but this is not always the case. Users need to look carefully at the SSD they plan to use to make sure they are getting the most for their system spend. Continue reading “DRAM vs. SLC SSD – Which Makes More Sense?”
The SSD Guy has been asked a number of questions lately about SSDs and RAID. Most of these center around the difference in failure behaviors between SSDs and HDDs – HDDs fail randomly (if ever), while SSDs fail relatively predictably due to wear.
Oddly enough, SSD failures due to wear make them a little friendlier than HDDs. The wear mechanism is managed by the controller in the SSD. SSDs have spare blocks, and the controller manages those blocks, so the controller understands exactly how much wear the SSD has undergone and how much room is left before the SSD will start to have difficulties. Continue reading “SSDs and RAID”