It turns out that my previous messages were on the right track. There was damage to the CPU socket, fortunately not of the replace-the-motherboard variety. I ordered a pair of CPUs (as I thought I could at least use all four DIMMs by putting two on each CPU). When I installed the first CPU I noticed something not quite right in the socket but ignored it at that point. Here's what I saw (I have circled the problem):  [IMAGE] But with the second CPU installed I was getting E1410 errors and the machine wouldn't boot so I had to take everything apart again and investigate.  When I looked more closely I realised that this pin was out of place (I'm not sure if it was bent or just caught on the neighbouring pin) but I managed to get it back from the red position to the green position. [IMAGE] That didn't solve my dual-CPU issue but I found that with one CPU, it would now see all 64GB, which it had not done before. So the original memory issue was apparently due to that pin above. Ultimately (for anyone who is interested) I did resolve the E1410 error - I think what did it was cleaning the second CPU socket by dabbing with a tissue moistened with isopropyl alcohol as Intel or Dell documentation mentions somewhere. As of now the machine boots with two L5640s and 64GB RAM (16GB in each of A1, A2, B1, B2), and I hope it will remain stable.
I have a T410 with I bought with a single E5504 processor and 2x2GB RAM. I would like to run it with 64GB so I bought four 16GB memory modules: Micron 16GB 2RX4 PC3L-12800R. According to the following document this should be supported, if configured for Optimizer mode in the BIOS. [URL] I have changed the BIOS setting (after I remembered it the first time booting failed with four modules) and I can boot the server with two of these installed (in A1 and A2) - the BIOS says that the RAM is running at 800MHz and I understand that to be a limitation of the CPU. But if I install all four modules, or even just three (in A1, A2, A3) the server appears not to boot - it sits at "Configuring memory, please wait." I haven't left it for hours to get past that, could it be that that's what I need to do? I'm wondering if this might also be a limitation of the processor. But the processor spec page seems to indicate that it supports three memory channels and much more than the 64GB I have. Some clarifications: Does anyone have an idea what the issue might be? Thanks
Memory configuration in T410 with E5504?