Building the perfect machine

hi people u guyz r great help. well i want to ask that

i have bought asus p5sd2-vm ddr2 board with sis 672 chipset. and ram667mhz currently running at only333hhz if its a dual channel matter so why my friends mobo intel dg31pr is running at full 800mhz(we both use single 1gb ram stick)
although that friends mobo is same as slow as mine i am not impressed by dual cores. my old sis 964 p4 was better

[url=http://www.asus.com/Product.aspx?P_ID=napibCwKrjGDncvA&content=specifications][/url]

now i wonder that sis are slow
or are they slow no more?
coz

other option for me is to pay extra and get asus p5kpl-cm board with intel chipset and ram800mhz

i have limited monet further that i can guy a 1gb ram instead of paying board replacement charges at same cost

and i heard that seagate hdd are reporting faults is it?

i am asking coz i need hdd too.
and my dealer only offer seagate 7200.1x barracude, sata in 250 gb is not available. should new w.d sata be good instead of seagate?

thanks r_manic

but i am wondring that my asus p5sd2-vm board is sis chipset with 667ram mhz
i am just grown concern that people say intel chipset is best. well from my experience i never liked intel except ther p3 board D815. which is still relatively expensive in resale market.
i just bought that board resently where there was another board asus p5gc-mx with intel chipset with 800ram mhz. i dont think 667 and 800 is a noticeable performance d/f to wast extra money.

i am asking .... is my current sis chipset really will be slow compared to that intel chipset one? i am not goint to use on-board vga neither i am concerned abt no of usb ports or audio. i concern just hdd access ram and 3d (like geforce card) performane on my board (as per sis and intel chipset on asus d/f) i hope ull try to understand what i mean