[Q] Hey guys, newbie here, got a question topic

I am sorry if what im about to ask is already posted somewhere (probably is), but this forum is pretty vast and I couldnt find what im looking for. The question is this, Im using Vanir ROM. Now with the inbuilt kernel I had around 20k benchmark on antutu. I flash hells core, excited to see any difference and whoop, i got 14k. Also i checked the part with 3D testing and fps was higher for about 5-7 points. So what Im asking is this,What is the meaning of this and also how can I, how to put it to not sound noobish, tweak the kernel to perform/save battery etc.?Because Im assuming thats not the top what HellsCore kernel can do, am I right? Or if you guys have any kernels to recommend, all is appreciated. Also if this helps, Im using Nexus 4, Vanir ROM(as posted above) and dont know what else would you need to know to answer.

Thanks in advance

/So I rebooted and now I am on 20840 for some reason.