AMD @ 4x4.1Ghz slower than Intel @ 2x1.7Ghz

Hi,

I have a code which solve a 2D HJB equation by a mix of ADI and explicit methods. I have been quite surprised to discover that the code runs faster (20% diff) on my old laptop than on my new desktop. Does anybody have an idea why is that so ? Every other programs run faster on the desktop.

Matlab version : Student 2011a

My Desktop : Processor : AMD A10-6800K - 4 cores @ 4.1Ghz Memory : 8GB Graphic card : GTX650 2GB

My Laptop (bought 2,5 years ago): Processor : Intel i5-2557M @ 1.7Ghz Memory : 4GB Graphic card : no idea

Windows 7 64 bit on both computers

Answer 1

[Iain]

Does the old laptop have:

 A bigger cache? - Allowing faster memory access to a small area of memory?
 A better cache least recently used control algorithm? - Reducing the amount of interrupting main memory access has to do?
 Better automatic restructuring of code - Allowing more operations to be done in parallel
 More floating point ALUs? - Allowing more operations to be done in parallel
 More fixed point ALUs? - Allowing more operations to be done in parallel
 Different programs running? - Allowing the space in memory thats used to not split over pages or anything that interferes with the cache manamgement algorithm.