On 09/07/2017 01:24 PM, Kyösti Mälkki wrote: > 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
Thanks a lot for the information! :) I had some suspicions about socket/board support too as I think also DIMMs have the same issue. Since I really wanted ECC capability, I'll probably get a PCEngines APU with 4GB of RAM, which was designed for ECC and seems to have it enabled in their stock firmware (coreboot-based) from the feedback I saw. From the schematics https://pcengines.ch/schema/apu2c.pdf it seems they have one screen port connected to a pinout on the board, although stock firmware disables it to use less power. Can do without screen too if I can't hack it, it's main usage will be network infrastructure anyway. Was just a nice bonus. -Alberto -- coreboot mailing list: [email protected] https://mail.coreboot.org/mailman/listinfo/coreboot
