blazorthon
Glorious
- Sep 24, 2010
- 14,022
- 21
- 43,265
[citation][nom]oxford373[/nom]from the first i saw the bulldozer review there wasn't any benefit from bulldozer architecture at all .since the idea behind bulldozer is to drive efficiency like hyper threading do but the problem is bulldozer(cores in pairs) is 75% slower IPC ,so core i5 works as fast as almost 7cores AMD at the same clock ,would be happy if amd just forget about bulldozer architecture and make native cores like phenome, but i don't think that will happen after 3 years of researches and developing bulldozer architecture[/citation]
Sorry, but pretty much everything that you said is wrong. Bulldozer CPUs have only slightly lower performance per Hz than Phenom II, the six core FXs beat i5s in highly threaded performance, and Bulldozer's problems aren't the architecture, only the implementation. Bulldozer is a great architecture layout.
1. Bulldozer CPUs have a completely computer generated design. Computers know the fastest way to design a CPU, not the way to design the fastest CPU. This increases die size and power consumption by about 20% each and decreases performance by about 20% (a more than 40% drop in power efficiency aka performance per watt). Most CPUs have performance-critical parts hand-optimized to solve that problem.
2. Bulldozer CPUs have huge cache latencies. This is a problem that they share with Phenom II CPUs.
3. Bulldozer has a poor memory controller. It gives about 25% less memory bandwidth than a Sandy Bridge memory controller with memory of the same frequency and amount of channels. This is the same memory controller that is used in Llano.
4. Bulldozer CPUs have soft-edge flip-flops. This also hurts performance and power efficiency badly.
These here are all non-architectural problems and solving them could improve performance and power efficiency incredibly. Piledriver is making use of some improvements here (such as using hard-edge flip-flops and also improving branch prediction, prefetch, and scheduling) and we will likely see more improvements in Piledriver's successors, Steamroller and Excavator. Why abandon an architecture when the architecture isn't even the problem?
Also, Bulldozer has been in development for much longer than you seem to think that it has.
Sorry, but pretty much everything that you said is wrong. Bulldozer CPUs have only slightly lower performance per Hz than Phenom II, the six core FXs beat i5s in highly threaded performance, and Bulldozer's problems aren't the architecture, only the implementation. Bulldozer is a great architecture layout.
1. Bulldozer CPUs have a completely computer generated design. Computers know the fastest way to design a CPU, not the way to design the fastest CPU. This increases die size and power consumption by about 20% each and decreases performance by about 20% (a more than 40% drop in power efficiency aka performance per watt). Most CPUs have performance-critical parts hand-optimized to solve that problem.
2. Bulldozer CPUs have huge cache latencies. This is a problem that they share with Phenom II CPUs.
3. Bulldozer has a poor memory controller. It gives about 25% less memory bandwidth than a Sandy Bridge memory controller with memory of the same frequency and amount of channels. This is the same memory controller that is used in Llano.
4. Bulldozer CPUs have soft-edge flip-flops. This also hurts performance and power efficiency badly.
These here are all non-architectural problems and solving them could improve performance and power efficiency incredibly. Piledriver is making use of some improvements here (such as using hard-edge flip-flops and also improving branch prediction, prefetch, and scheduling) and we will likely see more improvements in Piledriver's successors, Steamroller and Excavator. Why abandon an architecture when the architecture isn't even the problem?
Also, Bulldozer has been in development for much longer than you seem to think that it has.
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