A-Tech 16GB DDR4 3200MHz PC4-25600 ECC RDIMM 1Rx8 Single Rank 1.2V ECC Registered DIMM 288-Pin Server & Workstation RAM Memory Upgrade Module (A-Tech Enterprise Series)

Initial review after 1 hour. Will update if anything changes. Bought A-Tech kit containing two 16GB 3200MHz ECC modules for Dell Precision 5820 workstation with Xeon W-2223 cpu. Existing ECC memory are two 8GB modules supplied by Dell: each 8GB module is a Micron part rated at 3200MHz but the 5820 runs them at 2666MHz system memory. The manual does not document mixing 8GB with 16GB modules but I wanted 48GB total. I kept the two 8GB in DIMM1 and DIMM2, and finally added the two 16GB in DIMM3 and DIMM4. The motherboard has the physical slots out of order with the DIMMx numbering so pay attention (initially I put the 16GB modules in DIMM5 and DIMM6 but my test application ran ~20% slower than final DIMM3 and DIMM4 locations). Make sure the side cover is back in place before booting the Dell 5820. The BIOS picked up the memory had changed and then booted into my OS. All good - Ubuntu 22.04 OS shows 48GB RAM available. Good product.