CPU watchtower

AMD Needs a Multi-Core Killer App

AMD quad core does have some advantages: better performance on multi-threaded memory-intensive code and much less power dissipation when idling. One place where AMD will certainly help save on electricity bills is in data centers where many servers sit at idle throughout the night. In other areas, AMD lacks a performance edge. There are a couple main reasons for this. First, the L2 cache is too small. Barcelona's L2 cache at 512 KB per core is even less than that for the current dual core Opteron and far less than what is available on Intel CPU's. The other reason is that the Intel Core 2 architecture executes more instructions per cycle: up to 5 per clock cycle per core if you include the macro ops fusion feature, while Barcelona comes in at a maximum of 3. For AMD to win, it cannot stay one step behind. One has to wonder why AMD makes design decisions that leave it one step behind. It is even behind on clock speed. Its fewer pipeline stages makes it more difficult to introduce the product at higher clock speeds. Compare that to the Intel Tigerton or the IBM POWER6 which are available at high clock speeds immediately upon introduction. AMD will have to tweak more to get the frequency up (another delay).