As per Dell and Crucial specs 8 GB total. Having said that according to Memorystock here and Compuram here 16 GB. Confused yet? A good explanation for the difference lies here. This forum post though states that 16 GB does indeed work.
Hi all, We are trying to squeeze out some more life from my Wife's 580 MT as we try to find the funds to replace it. An old question, but back to the "how much RAM can you install?"   I've seen different answers, & it seems to relate to different Motherboards but here are the specs below, including the Motherboard details. We have 8 GB onboard right now - could 16 GB work? Thanks for any thoughts OS Name Microsoft Windows 10 Pro Version 10.0.19041 Build 19041 Processor Intel(R) Core(TM) i3 CPU BIOS Version/DateDell Inc.  A07, 13/11/2010 SMBIOS Version 2.6 Embedded Controller Version 255.255 BIOS Mode BaseBoard Manufacturer Dell BaseBoard Product 033FF6 BaseBoard Version A00 Installed Physical Memory (RAM) 8.00 GB
Inspiron 580 MT Maximum RAM