By: lurker (lurker9000.delete@this.realemail.mail), October 31, 2015 3:57 pm
Room: Moderated Discussions
juanrga (nospam.delete@this.juanrga.com) on October 31, 2015 12:50 pm wrote:
> We know the claimed IPC for Zen
I don't think IPC was the big problem for bulldozer. I think the problem was other bottlenecks. At least I remember reading an article about it on anandtech I think where it was compared to jaguar. And very poor FP performance of course.
> we know Papermaster admitted @ FAD 2015 that it is not enough to match Intel
Really? I honestly don't remember that.
> we know AMD will use a 14nm node that will not hit clocks so high as Intel 14nm;
Sure that's a safe guess, intel has a high-performance optimized node and samsung/global foundries have a low-power optimized node. But I think that's really only important in high-end desktop processors.
> I am sure the reason for 4ALU+2AGU and 128bit FP pipes is not because it is the best possible
> configuration. The real reason? We only can speculate at this time. Maybe a cache bottleneck did
> make adding a third AGU useless, maybe the fourth ALU is here for symmetry reasons, maybe...
Yes, but as I previously asked wouldn't at least disabling it save some power and heat? If it's there it means it is not completely useless, right? I'm not expert at hardware so I'm not sure if just disabling it actually helps, sorry if this is a dumb question.
> We know the claimed IPC for Zen
I don't think IPC was the big problem for bulldozer. I think the problem was other bottlenecks. At least I remember reading an article about it on anandtech I think where it was compared to jaguar. And very poor FP performance of course.
> we know Papermaster admitted @ FAD 2015 that it is not enough to match Intel
Really? I honestly don't remember that.
> we know AMD will use a 14nm node that will not hit clocks so high as Intel 14nm;
Sure that's a safe guess, intel has a high-performance optimized node and samsung/global foundries have a low-power optimized node. But I think that's really only important in high-end desktop processors.
> I am sure the reason for 4ALU+2AGU and 128bit FP pipes is not because it is the best possible
> configuration. The real reason? We only can speculate at this time. Maybe a cache bottleneck did
> make adding a third AGU useless, maybe the fourth ALU is here for symmetry reasons, maybe...
Yes, but as I previously asked wouldn't at least disabling it save some power and heat? If it's there it means it is not completely useless, right? I'm not expert at hardware so I'm not sure if just disabling it actually helps, sorry if this is a dumb question.