"Fast" appears to be the most common adjective applied to the iPad since its release. Pretty much everyone agrees the new device is quick, but we're beginning to get a picture of how
quick: two benchmarks run in recent days show the iPad is twice as fast as an iPhone 3GS, and appears to be quicker for some tasks than the Snapdragon processor in the Nexus One phone. Though the A4 system-on-a-chip (SoC) appears to have the same Cortex-A8 CPU as the iPhone 3GS, one observer theorizes that the speed bump is due to the fact that the iPad can read and write memory chunks two or three times bigger than other devices.
Craig Hockenberry, the developer of the Twitteriffic app, Craig Hockenberry, did a series of tests clocking the speed of the original iPhone
, running iPhone OS 2.0, back in August of 2007. Back then, the lack of an iPhone SDK meant that the device crawled, taking almost a hundred times longer to do many tasks in comparison to desktop computers. Hockenberry compared the performance of a new iPad and an unjailbroken iPhone 3GS
Meanwhile, Anand Lal Shimpi at AnandTech
ran some benchmarks comparing the iPad with the Nexus One phone
Any analysis of what might account for the difference between the two devices is going to be hampered by Apple's secrecy about the architecture of the iPad. Anand thought it likely that Apple had better interprocess communication due to improved design of Apple's custom SoC possibly including a faster memory bus. The A4's RAM is inside the chip itself
, so iFixit
had the reverse-engineering consultants at Chipworks go ahead and X-ray it
to discover two stacked Samsung DRAM chips. David Carey, vice president of technical intelligence at UBM TechInsights, told the Wall Street Journal
that these DRAMs read and write data in 64-bit chunks. "That helps it move a lot of data a lot faster," Carey said. "You are getting two to three times as many bits as would be characteristic in such products."
image via AnandTech