updated 06:05 pm EDT, Fri April 1, 2011
RBS believes A5 may be large to beat Tegra video
The iPad 2's speed edge over the Xoom may have come from inherent freedoms for Apple in designing the A5 chip over NVIDIA's Tegra 2, RBS analyst Didier Scemama said. He pointed out that NVIDIA by necessity had to design the Tegra 2 to its customers' price, which he estimated at $15 to $20. Apple wasn't hindered by having to please someone else and could pay Samsung $25 per chip for the A5 if it meant getting the fastest chip possible.
The decision may have explained the reason for the A5's much larger 122mm2 chip die versus the Tegra 2's 49mm2. Both are superficially identical with 1080p video out and modern 3D graphics, but NVIDIA's lower-powered graphics might not have needed as much space. Apple's control over how the A5 would be used let it include much faster PowerVR SGX543 graphics and design devices around it, Scemama implied.
The variant Apple uses, the SGX543MP2, is a true dual-core design. Tegra 2 claims eight cores in its GeForce graphics but is closer to NVIDIA's regular graphics, where each core is only handling a limited number of tasks.
Any advantage could change in the next several months. NVIDIA's smaller chip size might become an advantage for Kal El (Tegra 3), its first quad-core mobile chip. Apple will almost certainly follow suit but will have to work with an already large design.
The analyst suspected future chips from rivals might become considerably larger as they lean more heavily on graphics and overall performance. [via Barron's]