It sounds like slot 4 is bad. If the memory mode is optimizer then the memory should have been populated in slots 1,2,4,5. It appears that someone put the memory in slots 1,2,7,8 because slot 4 was bad. Unless the memory is in some other mode it should not have been populated that way. I don't see a memory mode that would be populated 1,2,7,8. I would test other memory modules in slot 4 to see if the error follows modules or errors on every module in slot 4. If slot 4 is bad then the system board will need to be replaced. Maximum memory performance will require 6 identical modules in slots 1-6.
Hello everybody, this is my first timer here. I replaced my old Dell PowerEdge T330 server,(service tag , CPU Xeon E3-1230 v6 3.5 GHz, 4 cores, RAID Perc H330 2 x 1 TB SATA, 32 Gb DDR-4, UDIMM, 2400 MHz, Windows 2012 R2) with a new  Dell PowerEdge R640 server (service tag , CPU Intel Xeon Silver 4114 2.2 GHz, 10 cores  (RAID Perc H730 mini, 4 x 300GB SCSI, 64 Gb DDR-4, double rank, ECC registered, 2666 MHz, Windows 2016 ).  The main use for the server is for running SCADA, and the corresponding Report application. During the testing of the new server, (Dell PowerEdge R640) we determined that the speed at which reports are generated is 40% slower cca, compared to the old server. Benchmark test show that the speed of the old memory is 29 Gb/s , and the speed of the new one is 25Gb. The software developer  says that the Ram speed causes a slower report generation. [IMAGE]   [IMAGE] The seller delivered the server with a 4 x 16 Gb, DDR-4, double rank, ECC registered, 2666 MHz, memory which was installed into: A1, A7, A2, A8. We tried the to make a memory arrangement: A1, A2, A4, A5, and while starting up BIOS it reported a mistake. [IMAGE] The PC works with memories arranged in the order : A1, A2, A3, A5, but the report generation is still very slow. How can we speed up the RAM? The PC is two months old, we already had a SSCI failure, and we had to replace the motherboard (it was not possible to activate the server)…... Best regard Dusan
RAM speed on the Dell PowerEdge R640