By: coppice (coppice.delete@this.dis.org), January 12, 2015 10:01 pm
Room: Moderated Discussions
Jouni Osmala (josmala.delete@this.cc.hut.fi) on January 11, 2015 4:50 am wrote:
> The Book definition of Many-core is several tens to
> hundreds of cores. And xeon-phi fits the description of several tens of cores. The core doesn't
> really need to be designed specifically for many-core to fit definition of many-core.
>
> While people often seem to think many-core and OoO are mutually exclusive, I consider that
> less aggressive OoO with reasonable ISA maybe optimal for many-core. Each core needs reasonable
> amount of cache to not overload the communication network for data traffic.
> We both know if some-one would make a 100 core processor today for server you
> can fit OoO logic to power budget, as long as it isn't too aggressive.
Book with a capital B? You mean the Bible defines manycore?
There is no well accepted definition of manycore. Personally, I think its really odd to call xeon-phi many core. If its core were designed to put many on a chip it would have been much simpler. For better or worse it was designed very much as a middle ground, distinct from the big fat multicore world, and the world of putting as many simple cores on a chip as possible. Its arithmetic is wider than that in Intel's multicore devices. That is definitely not a strategy for getting large numbers of cores on a die. Its taking things in another direction.
> The Book definition of Many-core is several tens to
> hundreds of cores. And xeon-phi fits the description of several tens of cores. The core doesn't
> really need to be designed specifically for many-core to fit definition of many-core.
>
> While people often seem to think many-core and OoO are mutually exclusive, I consider that
> less aggressive OoO with reasonable ISA maybe optimal for many-core. Each core needs reasonable
> amount of cache to not overload the communication network for data traffic.
> We both know if some-one would make a 100 core processor today for server you
> can fit OoO logic to power budget, as long as it isn't too aggressive.
Book with a capital B? You mean the Bible defines manycore?
There is no well accepted definition of manycore. Personally, I think its really odd to call xeon-phi many core. If its core were designed to put many on a chip it would have been much simpler. For better or worse it was designed very much as a middle ground, distinct from the big fat multicore world, and the world of putting as many simple cores on a chip as possible. Its arithmetic is wider than that in Intel's multicore devices. That is definitely not a strategy for getting large numbers of cores on a die. Its taking things in another direction.
