SSD Write Endurance 25nm Vs 34nm

[Christopher]

I'm not quite following up with this thread. Is there any impact by using non-compressible data to fill the SSD? (i.e. would certain controllers "cheat" with 0-fill and increase endurance?) What standard (settings) is used to join this thread?

The compressibility of data only matters for SandForce drives. They're the only controllers that can compress data/deduplicate data (there may be an enterprise controller made by some other company that does so as well, but I'm not sure. I'm mostly concerned with consumer drives.)

For the SandForce drives we've been using the 46 percent compressibility, but it's pretty much irrelevant for other drives/controllers. In terms of endurance gained by 0-fill for SandForce drives, I think it's six-of-one, half-dozen-the-other. Since the work never ends, you just end up with faster writes of more compressed stuff...

For example, the Mushkin Chronos Deluxe 60GB I had tested would write 90MBs - 100MBs with random data, and around 290MBs with 0-fill (with the endurance testing in ASU). If it's writing 290MBs with 0 fill, the actual writes to NAND are 100MBs. SandForce drives have a SMART value for host writes and a value for raw writes. If you divide the raw writes by host writes you can see the average compression ratio for all the data written to the drive. So a SandForce drive can't cheat in that sense -- you always know how much data is actually written to the NAND after the data has been compressed. At the 46 percent compression ratio in ASU I ended up with about 77 percent of host writes actually being written to NAND. It wouldn't be realistic to only use incompressible data as much of the data being written to the drive is compressible to one extent or another (but nowhere near 0 fill compressible). As a result, you end up with much lower than 1 write amplification, but modern drives are pretty good when it comes to WA.

I tested the Mushkin Chronos Deluxe SF2281 and it died pretty quick. I'm now testing a Samsung 830 64GB, but I just started it about 37 hours ago. If you're serious about testing a drive, I recommend testing a smaller-capacity drive. The two Intel 40GB drives started 7 months ago, and they're still going and going and going. My SF2281 made it 50 days, but that was kinda anomalous. There's no way to say how long a drive will last in advance, but I'd plan on the test lasting several months. I built a low power Sandy Bridge system that I can tuck out of the way in my apartment. I use a remote desktop application for my tablet to use as a monitor. The testing system will need to run 24/7, so having a quiet system is mandatory for me. But ASU doesn't require a lot of resources to endurance test, so if you're a folder you could probably use a folding rig. You could also use a laptop and just close the lid (disable close lid = sleep, never sleep) and stick it under your couch. I tried that for a while. Windows 7 isn't required, but TRIM helps a lot with average speed.