ECC RDIMM on Intel X58/ICH10R Chinese desktop boards? How? - Page 1
Forum section: electronics / general

author: ESXi
author_rank: Regular Contributor
timestamp: June 26, 2022, 04:19:26 pm
content: Yo,I was really wondering how did they do this?https://nonotree.xyz/en/shop/huananzhi-x58-deluxe/"Support non-ECC PC and ECC Server memorySupport DDR3 memory, three channel up to 48GB, supports ECC memory modules, with memory error correction."I have looked at the bios dump with AMIBCP and uh it seems like they added NUMA support. I've checked a ASUS P6T SE rev 1.01 board that I had laying around and on channel 0 I can measure the pins connected to the CPU socket (ECC pin). Yet still it ONLY accepts UDIMM, is this a bios limitation because of no NUMA support or a traces missing on the board? I do see a difference in DMI Table e.g a bigger list of Memory Devices, Physical Memory Array, and Memory Devices Mapped Address.I only managed to get PC3-10600E to work the "E" is the important factor here, it's unbuffered ECC. I do have a x56xx (Westmere-EP) series Xeon so the IMC should be compatible with this memory spec sheet also says it can run on 1.5v etc. Memory rank and organization seems to be compatibility too, yet it's stuck in some random boot code no post no nothing. I do have the correct microcode in the bios (pre meltdown and spectre one).I was reading this but it's rather limited I guess because it's reversed.https://sites.google.com/site/pinczakko/pinczakko-s-guide-to-ami-bios-reverse-engineering-1How can this Chinese board run with this memory I don't understand how this can be possible.There's not really any reason for me except for having old parts laying around and trying to mod it to get it to work just for fun. Would be cool I have free 3x 16gb ECC reg modules Already tried to inject SMBIOS module from that chinese board in to the bios it posted but never with the ECC mem installed. I only measured one pin to the CPU socket, I assume if one is connected the others are too because why else would they leave the rest out. I might be wrong, if so soldering voice coil wires to the cpu must be a fun thing too just to see what we can achieve. Probably all wires need to be the exact length/resistance or the timing will be off the chart and system instability will occur, idk aka kernel panic/bsod..

author: mariush
author_rank: Super Contributor
timestamp: June 26, 2022, 08:45:02 pm
content: Should change the title ... Don't see anywhere in the text that it's RDIMM as in REGISTERED memory sticks.It supports desktop non-ecc DDR3 and ECC DDR3 but both unregistered.You can use ECC memory in desktop motherboards and it's up to the bios if it rejects, ignores or uses the ECC part of the sticks, as the ECC is just an extra ram chip on the sticks, the memory controller inside CPUs support ECC

author: ESXi
author_rank: Regular Contributor
timestamp: June 26, 2022, 10:19:53 pm
content: Quote from: mariush on June 26, 2022, 08:45:02 pmI was talking about REGISTERED memory sticks. All the information is known to me, that Chinese board supports registered ecc. The unbuffered ecc indeed works with xeon I can confirm.Just the mystery of how that Chinese board managed to get it to work I guess they have added NUMA support in the AMI bios and obviously all ecc pins are connected to the cpu.

author: ESXi
author_rank: Regular Contributor
timestamp: June 27, 2022, 07:05:00 pm
content: I figured it out. They pulled Intel® 5520/5500 north bridges from old servers and put them on a new board.The chips are used and reused, can't be otherwise.Creative way of recycling old servers(e-waste), I have to admit.

author: macboy
author_rank: Super Contributor
timestamp: August 10, 2022, 03:50:53 pm
content: Quote from: ESXi on June 26, 2022, 10:19:53 pmNUMA != RegisteredNUMA (Non Uniform Memory Architecture) is not directly related to a specific memory type such as Registered/RDIMM. It mainly affects which processes get scheduled to run on which CPU cores, and where data is stored on memory (so that it is 'local' to the processes using it, i.e. on the memory attached to a particular CPU socket). It is an O/S level thing which requires hardware support. If your system has one CPU socket, then you probably have one NUMA node. Some high core count CPUs (esp. older ones) are built with more than one die, and can be an exception.Some motherboards can support ECC memory but not Registered (aka "fully buffered") memory. I have a LGA2011 board with a XEON E5 series CPU in it, but can't use RDIMMs. I use ECC memory instead. Too bad, becuase (used) RDIMM are usually much less expensive, but this is exactly why they are cheap... very few non-server systems can use them. Usually, ECC memory sticks can be used on a system which doesn't support ECC, the ECC feature is just not used in that case. Registered memory (RDIMM/PC3-xxxxR) does absolutely require hardware support, not only on the CPU (memory controller) itself, but on the motherboard as well. Registered memory DIMMs have an extra buffer device between the memory chips and the motherboard address/data lines, and this device must be controlled by the system.