I'm having the same problems. Other than knowing that my Computer isn't the best, I'm able to play 1.7.10 with decent Frame Rate, and even some small ModPacks, but almost all the Snapshots I tried and 1.8 pre1 and pre3 the lag spikes is still there. While Mining it isn't that bad, but when going to the surface it's lag as hell, kinda the type of lag you are used to get when you generate a new world, but even after days of playing its still the same.
Capitan
I'm having the same problems. Other than knowing that my Computer isn't the best, I'm able to play 1.7.10 with decent Frame Rate, and even some small ModPacks, but almost all the Snapshots I tried and 1.8 pre1 and pre3 the lag spikes is still there. While Mining it isn't that bad, but when going to the surface it's lag as hell, kinda the type of lag you are used to get when you generate a new world, but even after days of playing its still the same.