From the manual

Memory

The following table lists the memory specifications that are supported by your Dell Tower EBT2250.

Thanks for the reply.  I am aware of what it says in the manual.  The manual lists only the configurations that Dell sells; consider what it says about mass storage in the manual.  The manual lists mass storage for 3.5" SATA drives as up to 2 TB .. I currently have 2 x 18 TB drives in my computer, and it works fine.  The chipset inside the DBT2250 is the Z890 which should handle 64 GB DDR5 DIMMs, but I don't know what, if any, alternations Dell has made with the South Bridge of the EBT2250.

@KillerPooh01​ , with ASUS explicitly stating their Z890 chipset motherboards support 4x64GB, I'd assume the Dell Tower Plus EBT2250 (which has the same chipset, but only 2 RAM slots) supports 2x64GB.

Buying 64GB sticks compatible with ASUS Z890 motherboards would increase your odds of success.

I'd hedge my bets by purchasing somewhere they can be returned, though.

"with ASUS explicitly stating their Z890 chipset motherboards support 4x64GB, I'd assume the Dell Tower Plus EBT2250 (which has the same chipset, but only 2 RAM slots) supports 2x64GB."

Debatable. I can remember multiple cases where the retail specifications do not match Dell OEM specifications. All we can do is await user testing of non-tested configurations.

@DELL-Chris M​ .. Thanks for the clarification.  On the other hand, I have had several forerunners to the EBT2250 (XPS machines).  The mass storage spec on them was typically 2 TB max for added SATA hard drives but have always had much large drives.  On my EBT2250, I currently have 2 x 18 TB drives with no problems.  I suspect the MoBo on the EBT2250 will handle the larger DIMMs but as was suggested, I will only buy memory with the possibility of returning it should it not work ;-)

"Supported" wasn't a good choice of words on my part (I was thinking of underlying Intel chipset/CPU 64GB DIMM support).

By "assume" [it works], "increase your odds of success", and "hedge my bets" I'm implying there's no guarantee this works, but that I think it probably does and is worth trying.   (My last two Dell's both have RAM beyond Dell's officially supported capacity.)

As a surrogate for DIMM compatibility, I wouldn't use motherboards that focus on overclocking when looking for possible Dell Tower Plus EBT2250 compatible 64GB DIMMs.  I'd use something like ASUS "all around PC builders" PRIME Z890 motherboards.  Reason being is I'd be looking for RAM with well populated JEDEC SPD timing entries.  RAM for overclocking can sometimes have only a single JEDEC standard timing entry, which limits the option to step down to a compatible timing in a "standard" build.

@KillerPooh01 Were you ever able to test if the Dell EBT2250 can support 128 GB of RAM? Can anyone else confirm or refute this?

I've got an update. If you go to Amazon and ask their AI assistant Rufus what the maximum RAM capacity of the Dell EBT2250 is, it says that it can support up to 96 GB of RAM. Again, this is a different answer from another source but I'd prefer to hear from someone who actually has it set up and working on their computer. Anyone?

An update for those still interested.  This 128GB kit from crucial works flawlessly at least with the lastest BIOS as of 5/29/25:

CP2K64G56C46U5

@mdchaser​ 

Are you saying that Amazon Crucial Pro 128GB Kit (2x64GB) CP2K64G56C46U5 works in your Tower Plus EBT2250?

You also state, "works flawlessly at least with the lastest BIOS as of 5/29/25".

Are you referring to BIOS 1.5.2 for Tower Plus EBT2250 dated 5/20/25?

I came across this link—does it confirm that 128GB is actually supported? 

https://www.newegg.com/p/1VK-0001-6N9N4#:~:text=2-,Keyboard,3.2%20Type%2DA%20Gen%201

@DELL-Chris M​ 

That is correct, as of 5/29/25 the latest bios worked great with the crucial kit of ram.  The machine has been updated since and had worked on all of the newer bios versions as well.  Likely the listed limitation is just a support choice and the machine has always supported 128GB.

Thanks. Just to triple-check, @DELL-Chris M 's post has this link: https://www.amazon.com/Crucial-5600MHz-5200MHz-Compatible-CP2K64G56C46U5/dp/B0DSR5P84D?th=1

Is this the one you mentioned in your pervious post?

I recently purchased the 128GB Crucial kit (from Amazon) mentioned above, installed it, and it's working perfectly.

Big thanks to everyone here for the helpful info—especially @mdchaser 

I purchased the Crucial 64 gig kit

CT2K32G56C46U5

that has been the popular upgrade and on YouTube to get this machine to 64 gig mentioned in the forums since April/May.  Can anyone confirm if the newer bios updates over the summer have enabled the machine to utilize 128 gig instead of 64?  I just got the 64 gig kit yesterday and will get the machine next week.  I am now debating if I should say to heck with it and jump to 128 gigs.  I am concerned about there being future bios updates that may cause for 128 gigs to no longer be supported since Dell keeps recognizing 64 gigs to be the maximum officially supported limit.