How much ram can a Optiplex 790 use

Dell and Crucial specs state 16GB. But this forum post and this page at Memory stock list 32GB as the real world maximum. Dell specs are not always the gospel on memory capabilities. I have an E5420 Latitude and the specs state 8GB max but I have 16GB running merrily without a problem.

@JOcean​ on the second link website it says the mini tower can have 16gbs and the desktop 32, the desktop and mini tower (which i have) have the same motherboard (I think, they look and almost are the same) but i haven't seen anywhere explicitly saying that the mini tower can have 32gbs. Would it be worth it to buy 16gb (4x4gb) and just leave it at that or as you said, the specs  for your pc says the max is 8 but you have 16 working fine, would it be worth it to get 32gb (4x8gb) and risk it or should i try getting a 2x8gbs and use the ram i have in my pc to add up to 20gbs?

Re:  How much ram can a OptiPlex 790 use?

Some users validated 32GB capacity on their systems at this now closed discussion https://www.dell.com/community/en/conversations/desktops-general-locked-topics/32gb-ram-in-an-optiplex-790990/647f2592f4ccf8a8de9cd498?page=1

While it's not advisable to invest more money into a system at that age as the system can cease to operate at anytime, you can carefully select vendors whom would accept (30 days) term of free return to protect your upgrade investment.  Many sellers on this shopping site are offering 8GB module in their memory kits.  That is another indication of high possibility for a 32GB upgrade plan.

https://www.amazon.com/dell-optiplex-790-memory/s?k=dell+optiplex+790+memory

One of our forum users ran 24GB in his 790.  The 790, and it's successor, the 7010 come from a generation of Optiplex's whereas it's not unusual to exceed RAM spec.  Not too unusual to run 32GB in it.