PS CS5 faster in OSX ?

Hey all
Well i was working on designing a scene on my PC, but found out that it sometimes becomes slow,or it takes quite some minutes to apply a Blur(especially the Radial blur), so i decided to test it on my uncles iMac and surprisingly it loaded the application faster and also i found that it took less time to apply this blur. and overall i found it faster.
So is CS5 overall faster on OS X ? or i was experiencing a bug maybe on the windows ?This is the first time i tested it on both OS's so I'm sorry if its been asked before
PC specs
i7 860 @ stock(2.8)
8GB DDR3 1333 RAM
ATI HD 5970
1TB HDD(7200 RPM/32mb cache)
Windows 7 Ultimate 64bit

iMacs specs
i5 2.6(Quad core)
4GB DDR3 1333 RAM
ATI HD 4850
1TB HDD
Snow Leopard(I think its 10.6.4)

Thanks

 

Yes

 

Yes it is