Your new laptop should be fine. You did not mention what brand it was. I play a lot of games on steam and my spec are similar to your OLD laptop with no problem. I can even run Planet Coaster and I just meet the minimum specs for that game. A lot of vendors load a lot of bloatware and stuff you may never use on these computer that can slow things down it they are running in the background or look for auto updates all the time. Another thing is the video card/drivers and video RAM. Do you have an integrated or dedicated video card? In integrated card may have some bottlenecks and could be causing you lag.