A quick dissection of the iPhone 4 by iFixit has discovered that it theoretically has performance as least as good as an iPad. The already-known A4 processor should run at the same 1GHz clock speed as seen in the Apple tablet, in spite of the smaller size, but with 512MB of memory should be better with multitasking. Whether Apple has quietly underclocked or otherwise detuned the A4 isn't known, but early benchmarking has suggested it's faster than an iPhone 3GS but not as fast as an iPad in practice.
