the questions are 1)Why everones telling gofor sli mobos wats the advantage of a sli and by adding two gfx card wat wil be the difference 2) dual channel is better then single in rams dint understand my freind told go for 512 X 2 as it gives dual channel and not for 1 gb direct 3)i have two diff. brand rams, and i want to put it together on my mobo so pls tell me wat to check on two rams i have loads of queries

1) Not all people recommend going for SLi. Personally, I think it's a complete waste of money. Why buy two video cards when 90% of the time, a single good card will perform just as well? Plus to run SLi, you need a more powerful PSU to handle the load of the two video cards. SLI mobos are usually more expensive than their non-SLi (Ultra) "brothers" too...so running SLi is quite an investment. However, you can buy an SLi board & just run a single video card. 2) Dual means two. You obviously cannot run a single 1GB stick of RAM in dual channel mode. Dual channel mode potentially doubles the available RAM bandwidth, so if you have 2 x PC3200, you theoretically have a max bandwidth of 6400MB/s. If you only have one stick of PC3200, the best you can do is 3200MB/s. 3) you can *usually* run two different brands of RAM together, but they will have to be run at the speed of the slowest stick. If you pair up PC2100 (DDR266) with PC3200 (DDR400), both sticks must run at PC2100 speed. There are also timing issues to deal with...those will also default to the slowest, but you *may* be able to "force" them by manually configuring the BIOS settings. If you want to run two different brands in dual channel mode, their specs have to be the same (or darn close).