Thanks poc; Then it gets confusing again! On Wed, 2009-09-30 at 10:53 -0430, Patrick O'Callaghan wrote: > On Wed, 2009-09-30 at 10:55 -0400, William Case wrote: > > It's the data that's stored in units of 8 bits. When addresses are > stored then of course the same applies. When they're on the address > lines of the memory bus, they may be in groups of 16 or 32 or 64 > (depends on the bus design). None of this matters to you as a > programmer. > Understood -- I think. Put another way, on a 64 bit machine if the memory bus is 32 lines wide the data, or whatever, would flow with the first 32 bits immediately followed by the second 32 bits -- right? (I am trying to avoid discussing whether data flows on the rising edge or falling edge of a clock tick etc.) > Note that the pedantic name for a group of 8 bits is "octet". A "byte" > is the number of bits required to represent a character in some > encoding. > > > When you say "chips" above I assume you mean cell, i.e. chip = cell = > > 1 capacitor and 1 transistor for storage of 1 bit. > > A chip has a whole bunch of cells (in the millions these days). They > aren't the same. Then what was Markku referring to when he said "A typical 64-bit DIMM "stick" has eight 8-bit wide chips." The chip is one of the minute black chips I can just barely see on a RAM stick --? That is what I originally thought. Markku's statement then implies that a 64 bit qword is stored in an 8 x 8 array of cells. True? By the Way: The definition of a 'word' seems to be all over the place. With Intel, the definition I have read says a 'word' is 16 bits, a 'double word (dword)' is 32 bits, and a 'quadruple word (qword)' is 64 bits. The specs for the 64 bit AMD CPU I used to have defined a 'word' as whatever the machine said it was. In my case at the time, a 'word' would have been 64 bits. ???? I raised the question of 'words' with my local Linux Users Group and simply got caught in a long debate amongst them with huge digressions that resolved nothing to my satisfaction. -- Regards Bill Fedora 11, Gnome 2.26.3 Evo.2.26.3, Emacs 23.1.1 -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
