I'm mostly familiar with Dell servers and their hardware. What I can tell thus far is the model server you have came out in 2013. That is before SSDs became mainstream.
Using the comparable Dell R710 (2010) and R720 (2013) I found that while SSDs do increase performance, it's simply not to the point of a more modern computer with a modern hard disk controller. The Dell R740s I have recently installed make the 12GBs SAS SSD drives it has in it literally
S C R E A M.
If you want to take full advantage of SSD, have a more modern hard disk controller - at least 2017 or higher.
James