buying a second 9800gt for dual graphics card

I just bought a Dell and in order to save money i decided to buy only one 9800GT since the second one is an additional $250, now the question is can I use any other 9800GT to work with my video card or does it have to be the exact same card? And if so do I have to tweak it to make it work or just plug and pl

Because he has a dell he can forget about overclocking. If you dont have a nVidia chipset you can forget about SLI.

He will be getting 2 of the same cards (2 9800 gt's). The question is if he has a motherboard that allows for sli

im gonna go out on a limb and say you bought a xps 630i? if so then yes you can buy another 9800GT and SLI it. the mobo that comes with the xps 630i is a dell limited 650i SLI. i say limited because it will not overclock any of the 45nm intel processors (q9300-q9550, i dont know the highest one) so if you got a cpu that starts with a Q9xxx your screwed for cpu overclocking. as for gpu overclocking, have at it it will overclock your gpu's. if it is a xps 630i i recommend you change the mobo or find someone who can help/do it for you, i put a EVGA 780i SLI in mine this passed friday and its overclock city.

Regardless of the chipset, Dell locks down all of their bios so you wouldn't be able to overclock the cpu anyways.

lol ok i got mixed up there. I thought you were talking about the poor overclockability of the 630i boards

There is SO much misinformation in this thread, it's ridiculous.

Dell has been relaxing restrictions in the BIOS for their modern gaming machines, so it IS possible to overclock a CPU in a Dell depending on the model/series (the top end XPS).

Now, regarding SLI, it is not entirely accurate to say that you can SLI cards of different brands as long as they're the same 'card' (by which I assume you meant GPU series). If two 9800GTs from, say, XFX and BFG are their basic models and both follow the nvidia reference design exactly, then yes you should be able to SLI them (theoretically). The problem here is that manufacturers will deviate from the reference designs in many, many varying ways. So, while two 9800GTs from two different companies might have the same GPU in them, it is possible that the two manufacturers are using different BIOS versions, and perhaps different brands and configurations of graphics RAM, rendering them incompatible in SLI.

In the end, it's always best to get the exact same make and model of card for SLI, though it is, at least theoretically, possible to SLI cards from different brands.