Monday, 28 August 2017

hard drive - HDD vs SSD durability



I heard that SSD are less durable than HDD. Is it true ?



Answer



My first reaction to your question was: "My experience is exactly the opposite." Read on for exactly why, but first some background...


Both spinning and solid state drives have a limited life-span. There are some that are of the opinion that SSDs have as good or better a life-span than similar spinning hard drives given the same usage patterns.


Note however that not all SSDs are created equal. There are SLC drives such as the Intel X25-E, which tend to be much more expensive ($300 for a 32GB drive), but also are faster at writes and are more durable. The other architecture is called MLC, and is less expensive but may not be as good during writes as SLC and also may not last as long, largely because the memory cells have to be re-written in larger chunks. However, newer SSDs have better management firmware and last quite well.


But, back to your question... Everyone in my small company is running SSDs on their laptops. I've been running an Intel X25-M in mine for at least a year, maybe closer to two. I'd never go back to a spinning disc in my main laptop because of durability.


If you drop a laptop and the hard drive is spinning, you are almost certainly going to need to replace the hard drive. Earlier this year I dropped my laptop while it was running and after that it wouldn't even power on. I basically had to have everything but the CPU, RAM, and SSD replaced (motherboard, display, most of the parts of the case...). 3 or 4 years earlier I had a similar drop with a spinning drive. It survived for around a week after that, but quickly started generating errors.


So, in a laptop or other bump-prone environment like a carputer: SSDs are more durable hands down.


Another thing to consider though is how they fail. SSDs fail because they can no longer erase the cells. SSDs don't overwrite data, they tend to have a pool of unused blocks that they erase and make ready for use, and writes of existing blocks are sent to these new locations, rather than erasing existing data and writing it. Spinning hard drives tend to fail because the mechanical parts wear out and they start generating errors while writing and reading.


So one theory is that when the SSDs fail because of write cycle issues. you can still read the data off the drive, you just can't write anymore. Effectively making your SSD a read-only copy of your data when it failed.


My experience so far is fairly limited, less than a dozen drives over a couple of years for SSD versus over a thousand drives over 15 years for spinning. However, so far I do not feel that SSDs durability compared to spinning discs is insufficient, even for non-laptop use. Some of the very early SSDs were real crap, we had one vendor's 16GB SSD that died after a few weeks of use, and the replacement also died after a few weeks of use. However, current products, since the first generation Intel X25-M, I've been very happy with.


No comments:

Post a Comment

Where does Skype save my contact's avatars in Linux?

I'm using Skype on Linux. Where can I find images cached by skype of my contact's avatars? Answer I wanted to get those Skype avat...