What is the difference between the new 13" MacBook Pros and the previous version of the 13" MacBook Pro?

Very little, to be honest. The processor speeds have increase a little, from 2.4 GHz to 2.5 GHz and from 2.8 GHz to 2.9 GHz. The 2.9 GHz now ships with 8 GB of RAM instead of 4 GB. The SD card reader is now an SDXC card reader, and the FaceTime camera now supports 720p - tho' I must admit I'm not sure if the previous one supported 720p so I'm not sure if this is an upgrade.

Given how minor the changes are I'm still pretty happy with my early 2011 13" MBP.

USB 3 and faster RAM 1333 up to 1600. That's all.

Well spotted, missed the change to USB 3.

The processor is only upped by a little, sure, but it's the new model which is able to overclock to a significantly faster speed. Also the fans are much quieter- speaking from using both.

I don't believe the fans on the standard MBPs are the updated type. Only on the Retina display models as they need them to try and keep the system cool.

But I may be wrong.

Yeah, I have absolutely no idea whether the fans are actually updated or not, however they are significantly quieter. With the Late 2011 Macbook Pro I could sometimes not hear the sound of a video I was playing on youtube or whatever flash-based site I was using, but with this mid 2012 model I can't even tell from an auditory standpoint whether they are on or off. They recently went on full power when I was using Photobooth and I had to put my ear on the keyboard to confirm that they were on. My old one could almost be heard from the next room.

Ironically everything is running a LOT hotter as per istatpro numbers.

Note that iStatPro has not been updated in quite awhile and may not be reading the guts of a totally new system correctly. IIRC, the Late 2011 MBPs were beginning to tax iStatPro already, as they had newer sensors the older code was completely unaware of.

For strictly measuring temps on the guts of these newer Macs, maybe use Marcel Bresink's free Temperature Monitor? Last updated in March 2012. In my Late 2011 15" MBP, it picks up all 18 sensors...

http://www.bresink.de/osx/TemperatureMonitor.html

Or go whole hog for his Hardware Monitor, for oodles more info from the Mac. Follow the Products link from above.

also the proccesor is the new ivy bridge not the old sandy bridge witch is better and with the ivy bridge cpu it has intel hd integrated graphics 4000 the old one was 3000 and the new 4000 is almost doubles in prefrmance. and i think the fans have been upgreded i just got it and havent heard the fans once and ive tested a few games and nothing it just warms up.

ChrisSchlief wrote:

also the proccesor is the new ivy bridge not the old sandy bridge witch is better and with the ivy bridge cpu it has intel hd integrated graphics 4000 the old one was 3000 and the new 4000 is almost doubles in prefrmance. and i think the fans have been upgreded i just got it and havent heard the fans once and ive tested a few games and nothing it just warms up.

Ivy Bridge and Sandy Bridge are not CPU's, they are Motherboard chipsets.

whoops sorry i wasent thinking proporly but the new macbooks use 3rd gen cpu's and the older ones used 2nd gen right?

First you need to understand the difference between a CPU, and chips that are not CPU's.

The processor is the cpu and i'm pretty sure the new macbook use what intel classifies as their 3rd gen cpu's and the previouse models used 2nd gen ones.