How does SLI work?

[Chuck-Lee-Campbell]

So I have an GTX460 1GB SE version and since on its own its not that impressive im thinking of buying another card and since im a PC noob I have a few questions:

1. How does SLI work?

- Does the second card also require two 6-pin cables or does it get its
power from the bride connection?

- If so, are there any PSU that have four 6-pin connectors?

2. Can you connect any Nvidia card to another one?

- Would an GTX460 1GB SE version work well with the 768Mb version, or an GTX560?

3. Would my motherboard support this (Intel DP45SG)?

4. Can you put an AMD/ATI into the same computer with an Nvidia card?

5. Would my PSU (Energon EPS-750W) support this (AMD HD6870 and GTX460 if possible) or ( 2 GTX460s) setups?

6. Does every game support games, if not is there a list of games that do?

Here are my full PC specs if they are needed:

Processor: Intel Core2 Quad Q9550 2.83 GHz
GPU: Nvidia GTX460 1GB SE
Motherboard: Intel DP45SG
PSU: Energon EPS-750W
RAM: 6GB DDR3 1333 MHz
Hard-Drive: 1TB
Operating system: Windows 7 64-bit

 

[Wolfram23]

1) data is sent two 2 (or more) cards and they share the workload. Requires bridge.
-yes it needs it's own power from the PSU
-yes there's lots
2) No, they have to be the same make. I think the different RAM will SLI together (works for crossfire) but you would only end up with two 768mb cards (ie: the 1gb card loses 232mb)
3) No.
4) Yes... sort of. You cannot hybrid CF/SLI them. They would have to run independant of eachother. The only practical reason for this is to run ATI cards and use a low end Nvidia card for PhysX acceleration which requires a "hack" (aka GenL v1.04ff patch)
5) In theory yes. SLI 460s is already out of the question for you since your motherboard doesn't support it but the 6870s only need 1 6pin connector each. FYI, you can get molex-to-6pin adapters. That said, your PSU is a crappy brand (sorry).
6) Pretty much all games support SLI/CF. I run crossfire and have had very very few games not use it, and of them, they usually already run superbly well anyway.

My recommendation: Buy a decent PSU and either go with CF6850s, CF6870s, or a single 6970 or 570 which are roughly the same cost (technically less performance but also less power usage so you may get by with your current PSU).

 

[Chuck-Lee-Campbell]

Well my other options were an single HD6950 2GB version and then unlock it to an HD6970.

Would my motherboard and PSu support an single HD6950?

"In theory yes. SLI 460s is already out of the question for you since your motherboard doesn't support it but the 6870s only need 1 6pin connector each. FYI, you can get molex-to-6pin adapters."

So my motherboard would support two HD6870?