precision T7910 memory upgrade

I know that it is ancient, but I recently bought a T7910 as a relatively inexpensive vessel to hold a couple of GPUs so that I could tinker with local AI.  It is a dual E5-2695 V4 system with 32GB of RAM (four 8GB sticks) and accepted the two NVIDIA 3060s just fine (well, aside from the chassis cover no longer fitting).  

I decided to bump up the memory and add it to my Proxmox cluster to run a few VMs on it when I'm not in an AI mood.

It is currently running with the original 32GB which is comprised of four 8GB sticks in 
CPU0 Ch0 DIMM1
CPU0 Ch2 DIMM2
CPU1 Ch0 DIMM1
CPU1 Ch2 DIMM2

(as per the chart HERE)

All of that works great.

I picked up four 32GB sticks and did a 1 for 1 swap in all four of the slots above, removing the 8GBs.  Doesn't POST.

This new batch are Dell branded SNPC7GC which I believe checks all of the boxes that the T7910 requires (RDIMM and ECC) and they are 2400's which I understand is still within the limits of the T7910 (the 8GBs were 2133s).


I was sometimes getting the 2/7 amber code and sometimes just the solid white LED, but never any video.  I've tried a second set (by chance also Kingstons but without the Dell label) and had similar results.  The latter were used, the former were new.

I have tried every trick I can find....  The BIOS came with the latest A34, but I tried downgrading to A33.  No change, so I went back to A34. 

I've tried pulling the CMOS battery and removing the power cord for 20 mins.

I've tried adding just 1 stick to slot CPU0 Ch0 DIMM1 (works if I do that with one of the 8GB, but never with any of the 32's). 

I've tried just letting it sit there for 20-30 minutes when it is in one of it's "solid white" modes.  Memory training??

I've tried pulling out both of the 3060 GPUs in case they were somehow pushing the power 1300w power supply too close to the edge.  The original video card was the only installed card remaining.

It came with an NVIDIA Quadro that I've been using for the actual display.  I tried swapping that out with an old ATI Radeon that I dug up.

I've tried Secure Boot and not Secure Boot and a few other totally random BIOS options.

If this RAM should work, any other tricks to try?