I have Nimble for general workload and SQL / databases is one of the biggest areas of improvement vs enterprise storage that didn't have any flash.

Data is written to NVRAM then flushed to disk, so has very fast write performance (good for SQL, it uses same type of filesystem as NetApp, but wrote themselves to overcome some of the shortcomings / optimise for flash), reads are either from flash cache (has various clever stuff going on to maximise cache hit rates) or spinning disk.

Performance profiles wise, you store SQL data on volumes set to use SQL data profile (diff profiles for diff versions of SQL) and same for log files.

Those profiles are optimised to get maximum perf for SQL for their hardware, they've been collecting data via their cloud service for 5 yrs now so they've tuned these over the years to optimise performance.

It's 8kb as that's the paging size that SQL uses, they work off that not the allocation unit size to maximise performance.

Compression rates and cache hit % are very high, highest out of all the types of workload that have going to it.