As the self-proclaimed storage vigilante, I will keep bringing these idiocies up as I come across them.
So, the latest “thing” now is selling systems using “Raw IOPS” numbers.
Simply put, some vendors are selling based on the aggregate IOPS the system will do based on per-disk statistics and nothing else.
They are not providing realistic performance estimates for the proposed workload, with the appropriate RAID type and I/O sizes and hot vs cold data and what the storage controller overhead will be to do everything. That’s probably too much work.
For example, if one assumes 200x IOPS per disk, and 200 such disks are in the system, this vendor is showing 40,000 “Raw IOPS”.
This is about as useful as shoes on a snake. Probably less.
The reality is that this is the ultimate “it depends” scenario, since the achievable IOPS depend on far more than how many random 4K IOPS a single disk can sustain (just doing RAID6 could result in having to divide the raw IOPS by 6 where random writes are concerned – and that’s just one thing that affects performance, there are tons more!)
If you’re a customer reading this, you have the ultimate power to keep vendors honest. Use it!