3 ms·
Well, the core with its own memory is still a Von Neumann machine, is it not?
by LgWoodenBadger 10y ago
Well, the core with its own memory is still a Von Neumann machine, is it not?
- adrianratnapala 10y agoMore likely a Harvard machine, i.e. one where the instruction memory is distinct from the data memory. It is essentially what modern cores have with a their split caches, except those things are called "caches" because the architecture then has a lot of machinery for pretending to be a von Neumann Machine with a huge memory. This pretending is done because that's the kind of machine that software expects. But the first unices ran on machines with memories only as big as a modern L1-cache. Moreover, networking and parallelism are everyday issues for software now. It will be interesting to see if software evolves to explicitly recognise that it is really running on a network of small machines + a hierarchy of big external storage devices, of which DRAM is just one.
- visionscaper 10y agoYes, true, Von Neumann is dead, long live Von Neuman! ;) The difference is of course that we should not see the whole cluster of cores as a Von Neumann machine, the memory bandwidth is just too low to drive multiple cores with some external memory, memory must be as close as possible to the cores themselves. Quote from wtallis lower in this sub-thread : > You can't pretend that memory is all equidistant from the processor cores unless you want everything running equally slow.