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Staro 12.11.2009., 01:29   #607
McG
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Službeno predstavljanje Bulldozer arhitekture i Bobcat procesora

Bulldozer
In 2011 AMD will introduce two next-generation microarchitectures: Bulldozer for the high end desktop and server space and Bobcat for the price/power efficient ultra mobile market. First up, Bulldozer. This is a single Bulldozer core, but notice that it has two independent integer clusters, each with its own L1 data cache. The single FP cluster shares the L1 cache of the two integer clusters. Within each integer “core” are four pipelines, presumably half for ALUs and half for memory ops. That’s a narrower width than a single Phenom II core, but there are two integer clusters on a single Bulldozer core.
Bulldozer will also support AVX, hinted at by the two 128-bit FMAC units behind the FP scheduler. AMD is keeping the three level cache hierarchy of the current Phenom II architecture. A single Bulldozer core will appear to the OS as two cores, just like a Hyper Threaded Core i7. The difference is that AMD is duplicating more hardware in enabling per-core multithreading. The integer resources are all doubled, including the schedulers and d-caches. It’s only the FP resources that are shared between the threads. The benefit is you get much better multithreaded integer performance, the downside is a larger core.


Bobcat
AMD says that a single Bobcat is capable of scaling down to less than one watt of power. Typically a single microarchitecture is capable of efficiently scaling to an order of magnitude of TDP. If Bobcat can go low as 0.5W, the high end would be around 5W. If it’s closer to 1W at the low end then 10W would be the upper portion. Either way, it’s too low to compete in current mainstream notebooks, meaning that Bobcat is strictly a netbook/ultraportable core as AMD indicated in its slides. Eventually Bulldozer will probably scale down to take care of the mainstream mobile market. AMD provided very little detail here other than it delivers 90% of today’s mainstream performance in less than half of the silicon area. If AMD views mainstream as an Athlon II X2, then Bobcat would deliver 90% of that performance in a die area of less than 60mm^2. Clearly this is bigger than Atom, but that’s just a guess. Either way, the performance targets sound impressive. SSE1-3 are supported as well as hardware virtualization.
Izvor: AnandTech
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