I am planning to buy a new laptop that would be able to play most of the high graphics games(if not all).
I am confused between three models :
HP J049tx, Lenovo y510p(core i5 model) and Dell Inspiron 15 7000series(core i5 model).
ANS. Buying a laptop for gaming purpose have always remained a headache as every now and then games released come with different set of advisable configuration so whenever a new game arrives it makes our a day old system to look like a decade old because it wont support the current configuration we have got.
As per your laid down choice i would recommend you buying the Lenovo as per my personal experience HP & Dell doesn't give the performance as per their specification. So no matter if all of them stand to each other when considering the specs sheet but trust me at the end Lenovo will emerge out as a clear winner above that we cant deny the success it has achieved in a very short period of time by performing well & overcoming the tag of being a Chinese manufacturer.
Coming to the second doubt of your then i would say you should go for the 4th gen core-i7 as i5 may seems to be enough for now but having i7 on your system will make you future ready as i ust mentioned above. Having a future proof system will surely serve up to your needs that too knowing that no new technology is coming that might replace these processors so buying a system with i7 will be a good choice.
So our choice & suggestion will be to go with the Lenovo Ideapad Y510 powered by 4th gen core i7 with 8GB of RAM, 2GB Graphics and a TB of hard disk space. Well having a system with these specification will surely make your gaming experience a smoother one.