Ok, thanks! I had never seen a solution where parity information is stored in additional individual SDRAM chips. So in conclusion 128MiB of on-board SDRAM is used for packet memory, 64MiB of on-board SDRAM is used for packet memory parity information and replaceable DDR SDRAM SODIMM is used solely for the PFE microkernel.
regards, Martin On 9/29/15, Michael Loftis <mlof...@wgops.com> wrote: > The "extra" SDRAM chips. The packet memory has parity or ECC bits, I > actually do not recall for sure which, but the "extra" is for those > extra bits. > > On Tue, Sep 29, 2015 at 12:45 PM, Martin T <m4rtn...@gmail.com> wrote: >> What do you mean? >> >> >> thanks, >> Martin >> >> On Tue, Sep 29, 2015 at 8:45 PM, Michael Loftis <mlof...@wgops.com> >> wrote: >>> Parity/ECC. >>> >>> On Tue, Sep 29, 2015 at 7:32 AM, Martin T <m4rtn...@gmail.com> wrote: >>>> Hi, >>>> >>>> according to Juniper M10i Compact Forwarding Engine >>>> Board(http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/concept/cfeb-m10i-description.html) >>>> documentation it has 128 MiB SDRAM for packet memory and 128 MiB SDRAM >>>> for the microkernel. If I visually inspect the CFEB, then it has >>>> twelve "MT 46V8M16" DDR SDRAM chips which means 12x 134217728 bits, >>>> i.e. 192MiB of on-board soldered DDR SDRAM. Questions: >>>> >>>> 1) Are four "MT 46V8M16" DDR SDRAM chips actually not in use? If they >>>> are in use, then what for? >>>> >>>> 2) Am I correct that on-board soldered DRAM is used for shared packet >>>> buffer and installable DDR SDRAM SODIMM is used for the microkernel? >>>> >>>> >>>> thanks, >>>> Martin >>>> _______________________________________________ >>>> juniper-nsp mailing list juniper-nsp@puck.nether.net >>>> https://puck.nether.net/mailman/listinfo/juniper-nsp >>> >>> >>> >>> -- >>> >>> "Genius might be described as a supreme capacity for getting its >>> possessors >>> into trouble of all kinds." >>> -- Samuel Butler > > > > -- > > "Genius might be described as a supreme capacity for getting its possessors > into trouble of all kinds." > -- Samuel Butler > _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
