Put the cache on the SSD. Speed matters to the cache (both pure read/write performance and latency).
The SSD write limit is hugely overstated:
https://techreport.com/review/25889/the-ssd-endurance-experiment-500tb-update
After writing 500TB of data — the equivalent of 140 GB of data every day for 10 years — the consumer-class Samsung 840 250 GB has lost the ability to write to about 1% of its usable capacity. And that’s the worst stat in test.
My SSDs will fail someday, but so too will my mechanical hard drives. I don’t expect 10 years out of them.
[Mike Blutstein] “On the other hand, I have heard it is much faster to use an SSD for cache, plus you want your original files on a HDD as they are more reliable.”
I would not make the blanket statement that either HDDs or SSDs are more reliable. No matter what kind of drive you have your assets on, you should have a backup plan. One copy of data is way too close to zero copies of data for my taste.
Walter Soyka
Principal & Designer at Keen Live
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