Face recognition performance for iPhone 4 versus iPhone 5s

asked 2014-07-24 05:48:57 -0500

Hello.

I'm working on porting a face detection/recognition program using OpenCV code to iOS and Mac OS X. The exact same program, fed the exact same data, works on the order of 10 times faster on a brand-new iPhone 5s than it does on my old iPhone 4 (less than a second versus several seconds to identify someone). I suspect the dramatic difference in performance may be due to hardware improvements: the iPhone 4 has a 32-bit, 1-core processor running at 800 MHz and 512 MB RAM, while the iPhone 5s has a 2-core, 64-bit processor running at 1.3 GHz and 1 GB RAM, not to mention a lot of cache memory. Other people around here find a performance boost this dramatic hard to explain by hardware improvements alone. The performance of the software on other platforms tested, (Windows, Android, and Mac OS X) has been speedy. Does anyone out there what might be causing such a radical difference in performance? The only alternative ideas I have to Moore's law being responsible are 1) I did something to the software of the iPhone 4 which screwed it up and 2) the hardware of the iPhone 4 is deteriorating even faster than I thought and somehow affecting performance. Thanks in advance for any help anyone can provide.

Aaron Solomon Adelman

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Comments

Since the new Iphone has dual cores and a better processor I do think this is only the hardware that improved it. You have now two cores on which you can spawn threads to the multithreading options of OpenCV will increase alot!

StevenPuttemans gravatar imageStevenPuttemans ( 2014-07-24 09:40:30 -0500 )edit

No idea why someone downvoted this, I just added it back to 0. This seems a totally valid question.

StevenPuttemans gravatar imageStevenPuttemans ( 2014-07-25 08:08:18 -0500 )edit

I am also puzzled by application's performance on iPhone 4. It runs 10x slower than on the 4S and the hardware differences should only predict a 2X difference.

Buddhisthead gravatar imageBuddhisthead ( 2014-11-14 15:31:45 -0500 )edit