I've had an Intel X25-M 120GB SSD in operation as a boot drive for just shy of one year. It's been flawless.
In that time, SSD Toolbox says I've written 1.55TB of data on it.
At this rate, what is the estimated/average lifespan?
How many TB of writes is the norm for the lifespan for this series/model of SSD?
And is there somewhere I can view that information for various SSD drives?
I'm currently reading this article about enterprise use of SSDs and see references to how many writes per NAND cell but not sure how that equates to how much I've potentially written to the cells on mine: http://www.anandtech.com/show/5518/a-look-at-enterprise-performance-of-intel-ssds
For a different series of Intel SSD (320 series, which is newer and different die size), this info is stated:
http://www.anandtech.com/show/5518/a-look-at-enterprise-performance-of-intel-ssds/6 doesn't seem to help since my X25-M's E2 and E4 values are crazy (i.e., probably not supported). E2 shows 20477320 and E4 shows 943001248.
In that time, SSD Toolbox says I've written 1.55TB of data on it.
At this rate, what is the estimated/average lifespan?
How many TB of writes is the norm for the lifespan for this series/model of SSD?
And is there somewhere I can view that information for various SSD drives?
I'm currently reading this article about enterprise use of SSDs and see references to how many writes per NAND cell but not sure how that equates to how much I've potentially written to the cells on mine: http://www.anandtech.com/show/5518/a-look-at-enterprise-performance-of-intel-ssds
For a different series of Intel SSD (320 series, which is newer and different die size), this info is stated:
But I don't know the write amplification for my X25-M, nor the average p/e cycle count, so I'm not sure what formula to use to calculate that 1.55TB of writes against whatever the estimated p/e lifespan of the NAND cells on the X25-M is.If you divide the column on the right by the column on the left you'll come up with 125 program/erase cycles per cell (if you define 1TB as one trillion bytes). If we assume that each cell is good for 5000 p/e cycles (Intel's 25nm MLC NAND spec) then it means that we're actually writing 40x what we think we're writing. This 40x value gives us an upper bound for write amplification on Intel's SSD 320. That's far lower than the peak theoretical max write amplification of 256 (writing 2048KB for every 8KB write sent to the host), but it's safe to say that Intel's firmware won't let things get that bad.
Write amplification of 40x isn't very good but it's also not very realistic for the majority of workloads. Our database workloads are heavy but they are not perfectly random writes over all LBAs for the life of the drive. Those workloads do exist, but we're simply not an example of one. A more realistic, but still conservative estimate for write amplification in our case would be 10x (just based on some internal estimates for write amplification). The actual write amp is likely less than half that but again, I wanted to be conservative.
http://www.anandtech.com/show/5518/a-look-at-enterprise-performance-of-intel-ssds/6 doesn't seem to help since my X25-M's E2 and E4 values are crazy (i.e., probably not supported). E2 shows 20477320 and E4 shows 943001248.
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