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Hello @gakerby Dell machines have been known for very picky about mixing RAM, brands and capacity.  Even if you get confirmation from users validation, there is a chance that it might not work with yours.

For example, new sticks of Hynix 32GB can be had for around 50 USD from ecommerce store like A-Tech.  With lifetime warranty and free return.  Your research, your decision.  

Hi, and thanks for your suggestion about the eBay Hynix. Unfortunately, I suspect these are counterfeit. Certainly, they do not have the labeling that the 32GB Hynix sticks have in the Amazon Hynix store.  As I said in my post, when I researched Hynix memory sticks I found all the HMA41GR7MFR8N-TF 8GB sticks on Amazon and eBay were counterfeits.

I am reluctant to replace my 8GB Hynix wholly with higher capacity Hynix. My impression is that Hynix memory is not high quality (the Hynix store 32GB sticks got a bad review, for example) .

You write, Dell machines are 'very picky about mixing brands and capacity'. Am I to understand that mixing even different capacities (e.g. 8GB and 16GB) of the same brand (e.g. Hynix) is problematic?

Is there any quality memory brand sold by reputable retailers (not Amazon or eBay) that would work in my T7910? I would prefer to install 64GB or even 128GB (my T7910 has 1TB memory capacity, though I don't know if 1TB would work with my CPU). I'm looking to put in, depending on the price, 128GB.

Thanks again for your reply. I very much appreciate it. It was very helpful to learn about the problem of mixing brands/capacity.

Have a great day.

Mixing speeds can also be a problem.  It can be hit or miss whether machine will boot or simply downclock RAM to the speed of the slowest stick.

I've used A-Tech RAM for years with no hiccups.  I prefer it over the Hynix that went in a previous PC.  (Dell seems to prefer Hynix for their OEM.)

However, if in too much doubt over Amazon and eBay, Crucial is a good brand that comes often recommended for Dell's.  crucial.com

Being cautious and doing research before hand is a good thing.  However, contrary to your finding, many server RAM on the zone and the bay are real things.  Vendors parted them out from thousands of units which already reached end of life.  When businesses and enterprises flooded markets with off leased and eol machines, they don't retain value and being sold dirt cheap.  For example, a high end processor for your machine was over a thousand usd a piece.  It's less than a hundred now.  So are the RAM and GPU.  

It's my perspective and not intend to persuade you into buying anything.

I forgot you mentioned "other than Crucial" in your first post, my mistake.

Hi,

Thanks for your comment. Sorry for being so tardy for getting back to you..

I think I may as well go with four (4) Micron 32GB DDR4-3200 RDIMM PC4-25600 2Rx4 CL22 (MTA36ASF4G72PZ-3G2R). Unfortunately, they’re about $120 each. So far as I can tell 32GB RDIMM memory is priced pretty much the same wherever you look.

I’ve looked for 32GB on eBay but what they have doesn't seem to be that much cheaper than anywhere else.

Final question, I hope, I assume I’m better off with RDIMM rather than just DIMM memory and that there is nothing better I can use than RDIMM.

Thanks again for your comments. I very much appreciate them