xfx 7900gs 450/1320 vs xfx fatal1ty 7600 gt 256mb 650/1650

hi, i'm kind of new to this graphics card issue...

anyway, i think it's time to update my (ancient) ASUS eax600pro to something new, i've narrowed it down to these 2 v-cards

the XFX fatal1ty 7600GT 256MB 650/1600 and XFX 7900GS 256MB 450/1320 since they are almost equally priced..

I also see a thing called bandwidth, now i noticed the 7600gt chip has a lower bandwidth of around 34 gbit/s or so, and the 7900GS chip has one of 42.2 gbit/s.

so which would be faster?? the one with higher core/memory speeds or with greater bandwidth??
and does anyone know if the 7900GS makes alot of noise..?

so can anyone explain to me what is more important when shopping for vcards?... the bandwidth or the core/memory speed?..... i always thought it was about the core/memory speed....

Whats important is not core/memory speed, it's how well it performs on good old Toms graphics card charts.

There are quite a couple of graphics chips out there that all have differing performance per clock cycle, so even though the 7600GT has higher frequency, it has a less powerful core with less pixel pipe lines, (as Maizar mentioned) and thus is a poorer performer than the 7900GS.

But all you really need to check up on before you buy is, can your PSU handle the graphics card, will if fit in you're mobo (pointless getting a high performing PCIEX card when all your mobo has is an AGP slot, you'll get it to fit... with a hammer, and then all it'll give you is the magic blue smoke, if you're lucky) and how well it performs at the resolution you play games on, check this last part on toms graphics card charts.

P.S. get the 7900GS, i have one and it'll run most current games fine at 1600X1050 with all eye candy and at least 2X AA and more often than not 4X AA. As for noise i've got not clue how the XFX does but my Biostar is plenty quiet (i'm still amazed at how well my budget busting Biostar overclocks!)