The two Macbooks I have are Apple MacBook "Core 2 Duo" 2.0 13" (Unibody) MacBook 5,1 - http://www.everymac.com/systems/app...-2.0-aluminum-13-late-2008-unibody-specs.html Apple MacBook Pro "Core 2 Duo" 2.4 17" MacBookPro 3,1 - http://www.everymac.com/systems/app...k-pro-core-2-duo-2.4-17-santa-rosa-specs.html I have upgraded the ram on the MacBook to 4GB, the Pro also has 4GB, other than that the rest is as is. Both are running the latest version of OS X. The MacBook has 25Gb out of 160Gb free. The Pro has 40Gb out of 160Gb free. The problem is the MacBook runs extremely slow compared to the Pro. With the Pro I can run anything no problem...no lag, I can have as many programs as I want open at once (Xcode, Photoshop, Firefox, Mail etc..) However with the MacBook If I open more than any 2 programs everything becomes very sluggish. So if I have Xcode open and need to open Firefox I'll be waiting a good 30+ secs for firefox to open and even while using it it'll be slow. Opening anything else will just make my machine run extremely laggy or just start freezing. I understand that the Pro should be better but comparing the stats of the two there aren't that many differences. The Pro has a better L2/L3 Cache (1MB more) and the Processor Speed is of course slightly better. It also doesn't have integrated video card memory. On the other hand the MacBook has newer Ram. I'm just curious if anyone has any ideas why the MacBook is running so terribly compared to the Pro. Thanks!