Need Help fast please.

Both systems have the same graphics, both integrated into the CPU and as an add-in board equivalent, so the major difference is going to be the speed of the CPU. The 2nd system you list, with the i7 will have an advantage in CPU bound games, but honestly, unless you turn your graphics settings down on most games, you'll likely be GPU bound in everything you do with either system, meaning you probably won't see the advantage the i7 has in most games.

Not when the slow performance is caused by something other than the CPU. It doesn't matter how fast your CPU is if you pair it with medium to low end graphics.

RAM quantity only matters when you have an insufficient amount of it. Games that are not specifically coded to run in a 64-bit mode or be large address aware will not even be capable of addressing more than 2 GB of RAM. The extra RAM above what your game is using will be handy for Windows and other background tasks, but even at 6 GB, you likely won't be using it all during gaming. Only a few of the new games can take advantage of that much memory, and they will have more problems due to the limited graphics in most laptops long before the RAM becomes an issue.

The largest factor in your FPS is going to be your graphics card. There is no way around that. Your CPU, no matter how fast it may be, can not feed your graphics subsystem any faster than the graphics subsystem can accept the data. Once your GPU bottlenecks everything, the faster the CPU, the more time the CPU will sit idle.

A big factor in your lag is going to be the quality of your connection to the internet, and your ISP's connection to the broader internet's fabric. Provided your computer is not outright malfunctioning, or operating terribly, you can't do much for that on your end short of switching ISPs.

Well, I agree with you about the 750m being sufficient to run your games. It's hard to get a decent laptop with high end graphics for anything less than too much money.

I would not think the i5 will ever face a situation where you would benefit from the increase in speed that the i7 would provide in games. The 750m is just not fast enough to need more CPU power than what the i5 is offering. If you look at the specs for both chips, they are both dual-core chips with hyperthreading, thereby appearing as 4-core processors to Windows. The difference is going to be the speeds they are clocked at. I doubt you will see any appreciable difference in performance from the extra 1 MB cache on the i7. That's more to differentiate the two models than anything else.