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Top Solid State Disks and TB Drives Reviewed
Lucas123 writes "Computerworld has reviewed six of the latest hard disk drives, including 32GB and 64GB solid state disks, a low-energy consumption 'green' drive and several terabyte-size drives. With the exception of capacity, the solid state disk drives appear to beat spinning disk in every category, from CPU utilization, energy consumption and read/writes. The Samsung SSD drive was the most impressive, with a read speed of 100MB/sec and write speed of 80 MB/sec, compared to an average 59MB/sec and 60MB/sec read/write speed for a traditional hard drive."
Write Cycles: Even at the lowest estimate, 100,000 write cycles to failure
Meaning on a 32GB Drive, before you start seeing failures, you would have to (thanks to wear-leveling) write 32*100,000 GB, or 3.2Petabytes
at 60MB/sec write speed of the Samsung drives, you would need to write (and never, ever read) for 3,200,000,000/60, or ~53Million seconds straight.
53Million divided by 86,400 means you would need to be writing (and never ever reading) for ~617 Days straight (That's roughly 20 months of just writing, no reading, no downtime, etc...
So... the sky is not falling, these drives are slated to last longer than I've ever gotten a traditional drive to last in my laptop(s)
Almost forgot to mention, standard NAND of late has been more in the 500k-1M write cycle between failures range. 100k was earlier technology, so multiply numbers accordingly.
Will this ever die? The write cycle counts in modern flash is in the millions now. Doing the math you very easily get 20+ years before write cycle wear is a concern: http://www.storagesearch.com/ssdmyths-endurance.html
How many heavily used spinning drives do you know that last even 10+ years?
Yes I have. However, I've never had one magically get smaller on me in such a way that fsck decides that your done fixing the filesystem. With SSD, YES, I've had exactly that happen to me.
In my life, I've lost a total of about 42Kb be completely unrecoverable with spinning media (yes, I mean that number literally). I use RAID extensively, I was the DBA/SA/Developer at a place that had ~10TB of disk online for 5 years. In all that time, 42KB is all I lost. Oh, that was in the off-line, tertiary backup of the production database (it was one of 5 copies that could be used as a starting point for recovery, we also had the redo logs for 5 days, each DB was a snapshot from one of the previous 5 days). It was stored on bleeding edge IDE drives put in a RAID 5 array. We used it as a cheap staging area before pushing the data over Firewire/USB to a removable drive that an officer of the company took home as part of the disaster recovery system (it had only the most recent DB and redo logs). The guy didn't RMA the hot spare, and we had two drives fail in about 3 days while the hot spare was waiting for the RMA paper work to fill out. In that one particular case, using ddrescue, I recovered all of the data off of the RAID5 array but 42KB (even though it was an ext3 filesystem on LVM, on a RAID5 array, which made the recovery even more complex). Every other bit and byte of data in my life from spinning media that I cared about, I've recovered (I've had a number of drives die with data I didn't care about, but I could have recovered from if need be). Trust me, I know about reliability, backups, and how to manage media to ensure that failure doesn't happen. I know about failure modes of drives. I've hot swapped my fair share of drives, and done the RMA paperwork. I've been in charge of drives that losing any one of the ~200 drives would have cost 10 times as much as I made in a year if I couldn't reproduce the data on it within hours.
If it had been worth $10K, I'd have sent off the drive to get that 42KB of data recovered. But it wasn't. It's well understood how the failure mode of spinning media. People know exactly how to do things like erase drives securely. People know who to call that has a clean room that can remove the magentic media to and put it under a microscope to get the data recovered. SSD isn't nearly as mature in that sense.
All of that is really to say: Yes, I know something about disks and drives. My point is to say that SSD's aren't magic pixie dust in terms of reliablabilty. I've had exactly what he's saying I shouldn't worry about happen to me on a regular basis. Enough, that our engineering department has developed specific procedures to deal with them in the field. We've changed our release procedures to accout for them. If your going to use an SSD or flash drive, go kick the crap out of it. Don't believe on faith anything you read on Slashdot (including this post, which is anecdotal). We order lots of 5,000 flash disk, and you can bet that at least 100 of them has serious flaws within being fielded. The ones the developers and testing uses regularly develop problems in terms of months, not years. The manufacturer tells us essentially, it's not worth it to find those, so deal with it.
The whole point of replacing the laptop drive was to make the silly thing more reliable. But making it uber-reliable for 4 weeks until the write leveling crapped out wasn't the idea.
Kirby