Solved!
Go to SolutionOptiplex 790MT memory
Can 8gb dimms be used in these machines? I think I saw a discussion somewhere that an even older dell was successfully running a full 32 gb. My computer is a "refurbished" old minitower. Bios is A21. It has 4 memory slots and came with 4 Hynix dimms, 2gb each, for a total of 8gb. I'd like to take one or two of those out and replace with 8 gb dimms. Has anyone tried this? I realize dell specs do mandate 16gb max memory, but those specs are even more ancient than this computer, and I wonder if they even had 8gb dimms back then. If more info is needed, I can post better details. Thanks.
2654
0
Posted June 21st, 2019 18:00
Many thanks JOcean.
It looks like 8 Gb dimms worked fine for most everyone.
2626
0
Posted June 22nd, 2019 15:00
I finally finished reading that thread, and hope I picked up most of the important points. Seems the last half was arguing whether it works or not :)
There are so many types of memory though. I'd like to ask a few more questions ...
'
(I forgot to mention my computer has i5 2400 processor if that matters)
.
About 1rx8 and 2rx8 In general, either works , correct?
Buffered wont work
registered won't work.
Speed can be faster than what I already have, just won't run at it's max speed, right?
Bear with me, I'm slowly learning :)
2620
1
Posted June 22nd, 2019 17:00
Welcome to the Dell Community @donm4599x
Intel® Core™ i5-2400 Processor 6M Cache, up to 3.40 GHz
Max Memory Size 32GB DDR3 1066/1333
The only limitation would be your BIOS and ChipSet???
Always update BIOS when upgrading Memory and CPU.
Dell Optiplex 790 System BIOS Version A22, A22
Intel Core i5-2400 CPU upgrades:
http://www.cpu-upgrade.com/CPUs/Intel/Core_i5/i5-2400.html
You do have some good CPU's you can also upgrade. "Core i7-2600/K"
Best regards,
U2
2582
0
Posted June 24th, 2019 15:00
Thanks U2. The i7 is something I'll keep in mind, but right now, there isn't enough gain in speed to attract me ... it's only a little faster, it I understood the data. And the A22 bios looks like it only has a patch for some intel security fumble. I'm not sure how important that is, so not sure I'll risk it, but I did download it in case I ever work up the nerve to flash it. Digging through intel stuff is very confusing. I still haven't found any really clear info on how to change settings in Intel's HD 2000 video. Anyway, on the memory, I guess 2RX8 memory must be OK, since nobody mentioned it as a possible problem. I found some 8 Gb sticks on ebay that I may order soon. The good news for this week is that I was able to get the latest win 10 update (1903) installed, and didn't have any problem other than having to change some settings it dickered with. :)2489
0
Posted July 12th, 2019 18:00
2491
0
Posted July 12th, 2019 18:00
Just an update if anyone is interested. I chickened out on the 8gb modules, but I did buy a couple of 4 gb Hynix, same brand thats already in it. They seem to work fine, so now I have 12 gb total. Probably all I really need anyway. I did notice a problem with the memory diagnostic that comes with win 10. It hangs at 21% if the extended tests are running, unless I enable cache. From searching, it seems that this is a very old problem that microsoft still hasn't fixed ... normal for them. The dell diagnostic runs OK until click to continue testing the memory. Not sure what up with that. Maybe they got their stuff from microsoft.2305
0
Posted October 5th, 2019 14:00
Final update. Thanks for the help guys! I appreciate it.
I have added two 8gb ddr3 modules (dual rank), and still have the two 4 gb (single rank) modules, for a grand total of 24 gb. They have been running fine for over 2 weeks, and so far, have apparently not destroyed the 1.5 volt regulator chips on the ancient motherboard.
Probably more than I will ever need, so I won't try to upgrade this crusty old machine any more.
2294
1
Posted October 5th, 2019 18:00
Hi @donm4599x,
Sounds like your "crusty old machine" is running great.
397
0
Posted August 8th, 2020 09:00
That's nice to hear, I too have an Optiplex 790 MT and have a very similar situation (I have 2 2gb single rank and will add 2 4gb dual rank for a total of 12gb). Hopefully it works like yours.
JOcean
11 Legend
•
12621 Posts
•
69453 Points
2669
1
Posted June 21st, 2019 15:00
This forum post may help out. 16 GB is the official spec but it would appear that 32 has been tried. But it is not officially supported so you may be crossing your fingers and hope the retailer takes back the RAM if it is not successful.
https://www.dell.com/community/Desktops-General-Read-Only/32GB-RAM-in-an-Optiplex-790-990/td-p/3880625
I am not a Dell employee...I am forum volunteer
Serious work on an E5430 and constantly building and working on an i5-6500 Desktop