On Thu, Sep 7, 2017 at 1:40 PM, Nico Huber <[email protected]> wrote: > Hello Alberto, > > On 09/06/2017 09:30 PM, Alberto Bursi wrote: >> I've stumbled upon a Asrock IMB-A180-H board (a eKabini-based >> "industrial" mini-itx motherboard) on ebay and since it is supported by >> Coreboot I was considering about purchasing it. >> >> The APU onboard supports ECC ram (ECC so-dimms are kinda rare but I can >> find them), while of course the Asrock site does not say anything about >> ECC support (how unexpected). > > it's rather unlikely that a board supports it when the manufacturer > doesn't mention it. ECC support needs additional traces on the main- > board (as the bus is 72 bits wide instead of 64 bits). So just having > compatible chips doesn't suffice. >
See JEDEC Module 4.20.18 vs 4.20.21 standards. SODIMM 204-pin socket pinout for 64bit non-ECC vs 72bit ECC is already different. Some ground pins have been sacrificed to fit those extra ECC bits in the socket. In other words: no amount of open source will give you ECC SO-DIMM support when PCB was designed otherwise. That board is one of eKabini reference desings, schematics check tells me ECC pins of the APU SOC part are not connected. Kyösti -- coreboot mailing list: [email protected] https://mail.coreboot.org/mailman/listinfo/coreboot
