An inherently inefficient architecture
SolidFire, due to the requirement for mirroring, leaving a full node's worth of capacity free (to withstand a node failure) and not wanting to be over 90% full on the remaining space left, means usable:raw for a 4-way config is closer to 30%.
Assuming the industry standard 5:1 on the 30% means a very low final multiplier (Effective Capacity Ratio).
See here:
http://recoverymonkey.org/2016/05/19/the-importance-of-the-effective-capacity-ratio-in-modern-storage-systems/
This is all fairly basic math. Solidfire even has a sliding calculator on their website and you can verify the ratios easily using that.
See here:
http://www.solidfire.com/platform/hardware
There's the other wrinkle of metadata handling that makes it harder for SolidFire to use large SSDs since there's a RAM ratio that needs to be enforced, similar to XtremIO.
The value of SolidFire isn't dense flash storage. If you want that, look elsewhere.
Thx
D (Nimble employee & ex-NetApp)