Hello, The 5820/7820/7920 are configured as stock with the Flexbays connected to the onboard sata controller. As a result, your 5820 can use 4 sata drives in the 4 bays ( to use sas drives, you would have to add a sas controller and plug the cables to it ).  Now, lets speak about the nvme drive you want to install... the kit you bought is to be used if and only if the flexbay is converted to pci-e, and that's done with a different circuit board with the soldered sas connector. So, to use "that" specific kit, you need to get the kit that converts Bay 1 and 2 to pci-e ( for M.2 use with the kit you bought, or U.2 use with enterprise drives ) and that includes 2 circuits to replace the 2 hotswap sata circuit boards, and cables that go into the pci-e nvme motherboard onboard connector. Another cheaper and simpler solution is just to put the nvme into either a dell or a 3rd party ( asus by example ) pci-e adapter card that fits into a pci-e slot.   Bottom line : if not configured upon purchase, you need 2 different kits just to put a single nvme unit in one of the front flexbays ( and the 2nd flexbay on the same row would be then limited to be used either with another adapter kit or with an enterprise U.2 drive ). Or you can just use the nvme installed into a pci-e adapter card in a 4x mb slot ( if the adapter is for a single nvme ) or 16x mb slot ( if the adapter is for 4 nvme )   Whoever you spoke with , at dell (prosupport ?!?!?) had access to your full built and should have told you this, instead of partial info ( the adapting kit you bought, that's useless without having the bay converted ) leading to wasting time and money. Now I don't think you will have too many issues reselling the kit and recovering good part or all the money, but the time is a different issue.
Hi Community! I would like to add an SSD to my Precision T5820 to improve the performance of this machine. I would like to boot off this drive. Dell have been pretty useless so far at advising and supplying the parts, this saga has lasted most of the year I know looking at this forum that others have experienced the same! I have tried to take this into my own hands and have bought; - DELL M.2 Flex Bay Module Complete with M.2 module  (www.ebay.co.uk/i/224015692598) - ADATA XPG SX8200 Pro 1TB M.2 Gaming Solid State Drive (SSD), black (www.amazon.co.uk/dp/B07K1J3C23/ref=pe_3187911_185740111_TE_item) When installed the hard drive is not recognised anywhere. Am I missing a part to make this work successfully? Any ideas on possible solutions? Thanks in advance for your help Mark  
Precision T5820 adding SSD hard drive