i'm a noob in harddisk...

but i'm willing to buy a 500gb(or mayb 640gb) SATA desktop HDD~
i think i'll go for seagate or WD~

this's wat i heard from others:
1) now days all HDD is SATA 2... is that true?? SATA 2 faster than SATA~

2) all seagate 500gb 32mb buffer have been replace by 16mb~ no more 32mb for these days~ is that true??

hihi~ Pro Sifu's there~

i'm still a newbie here~ wanna ask some noob question~

i wan to buy a hard disk for my desktop pc~

prefer 500gb to 640gb seagate or WD~

which model are the best?? i'll using it mostly for Photoshop & Movies file transfer~

WD blue 500gb 32mb cache buffer should i get?? (i'm using it & feeling ok la~ no problem)

or Seagate?? 500gb 16mb cache buffer would do?? mayb 640gb WD??

i dont mind to pay but just i want the best in 500gb to 640gb range~

& mind explain y would u suggest me that??