New graphics card

[Commander_Fett]

I decided to utilize my SLI compatible motherboard and graphics card and get another gfx card. I have an NVidia GeForce GTX 275, and I plan to buy an NVidia GeForce 9800 GTX However, I'm not sure if I need to have 2 of the same graphics cards, or if my computer has enough power to feed the two. At the moment I have a toughpower 750 wat psu.
If I can't get those two gfx cards to work, I may swap for my mom's gts 250 and buy another one online, since those would be compatible.

So, my main question is, will it work? If not, what will I need to fix.

EDIT: where I'm getting the card
GTS 250: http://www.newegg.com/Product/Product.a ... -_-Product
GTX 9800: http://www.newegg.com/Product/Product.a ... -_-Product

[Hebes24]

I was under the impression that you needed two of the same graphics card to do SLI.

[Commander_Fett]

I know you can't mix a gtx with a gt, but I'm not sure about two different kinds of gtxs

EDIT: another option, if those 2 gfx cards are incompatible, would be to swap for my mom's gts 250 and buy another one of those instead of the gtx 9800. This would probably be better since I'd have 2 1gb gfx cards instead of an 896 and a 512 mb, and my mom would get a slight upgrade anyway. However, my parents are very hesitant at making any changes with computers, so we'll see.

EDIT2: it looks like a no go from my dad on swapping out gfx cards with my mom.

[VF501]

Some nVidia cards support Hybrid SLI which is using two different chipsets.

1 GTX275 outperforms 2x9800GTX or 2xGTS250.
9800GTX and GTS250 use the same G92 chipset, GTS250 is a revision of the 9800GTX
GTX series are G200 chipset and include the GTX260, GTX270, GTX275, GTX280, GTX285, and GTX295. The 9800GTX is just the highest clocked 9800 available.
SLI is not worth the cost as you gain 15% performance max for a larger power (and cash) drain.
For SLI GTX275 a 1000w PSU is recommended.

Running dual gfx is also not always SLI or Crossfire. As long as your board supports multiple cards (PCI-ex16 x2 or more) you can have multiple cards even without SLI and Crossfire ready boards. They just won't work in tandem. This kind of setup is normally seen on workstations for business or for Game Development/3D Movie production.

For a pure gaming rig SLI is not needed nor worth the cost. It's mostly flash with no substance. So only get a second card if you want to go Multi-monitor without straining one card too much.

EDIT: Also some older games are known to have issues running in SLI setups so its not foolproof either.

[Commander_Fett]

Actualy, after some more searching into my problem, I have come to believe the problem is actualy my motherboard, not my graphics card. I decided to install and play Crysis on my newly upgraded to windows 7 computer. However, it struggles on playing levels at the lowest settings (4-10 fps in general) as opposed to the 34 fps I was getting on high/very high settings with the same stuff on xp. When I looked at the system requirements on the game it says that a 3.2 GHz or faster cpu is needed for running the game unless on xp, and my current cpu is 2.6. It is highly unlikely my dad will let me get a different motherboard, and I doubt I could install it anyway, but in case I can get permission, does anyone know a good place to start?