It's the mosfets to the left of the CPU socket that regulate voltage going to the CPU. On cheap motherboards like the LE you will see few mosfets and no heat sink. This can cause problems when a high TDP CPU is fully stressed and possibly lead to failure.
Thanks...... Is this fx 6300 bottleneck amd radeon r9 280x....??? And plz suggest me a good mobo but cheap....
Depends on the game.
In most modern multi-threaded games that can use all 6 cores, no bottleneck. I've had an older Phenom II x6 1090T @ 4.0 GHz drive 2 Radeon HD 7950's in crossfire to 95-99% GPU usage in Crysis 3. Was able to max details and go 2x SMAA and kept it around 40-60 FPS. FX are a bit better for gaming and can OC higher. 4.4-4.5 GHz is fairly easy on Air with the FX 6300.
You will only see a bottleneck in older hames that can only use 2-3 cores. But then then you're talking the difference between 90 FPS and 70 FPS, both of which are still very playable, so in essence a non-issue.