http://www.uiscommunity.co.uk/home/m/2472935/article/408963/page/2

If you are having really long load times on Battlefield 3 then follow these guides on how to fix.

Nvidia Cards.

Open up Nvidia Control Panel
Click on Manage 3D Settings
Click on Program Settings
Select Battlefield 3 in the drop down box (If it's not there click add and find bf3.exe located C:\Program Files (x86)\Origin Games\Battlefield 3)
Find Threaded optimization
Turn On
Click Apply

You should now have fast load times when changing maps

AMD/ATI Cards

Download ATT http://downloads.guru3d.com/download.php?det=733
Install
Right click on the icon in the bottom right corner of your screen
Click on Tweaks
Click on Advanced Tweaks
In the drop down box select Multi Threaded Support
Change to 2 or 4 (Depending on how many cores you have on your CPU)
Make sure the radio box above is ticked
Click apply

This should fix it for you

I have an ATI card, and can confirm it worked for me. Ensure you install/run the ATI program as an admin. Got the level load times down to about 30-40 seconds (down from a few minutes). As I've a quad core, I changed the "max core" value to "4" and it worked like a charm :cool:

Where did you set the 'max core' value? Couldn't see it in the nvidia control panel

Ensure you read the "Nvidia Cards" bit, and not the "ATI" bit