How do medium large companies dry large slabs?

[KODAK]

Hey everyone! Finally signed up after following the forums for about two years intermittently. I'm starting to chainsaw mill and dry to learn and eventually sell my wood at appropriate pricing. Lots of good threads on realizing the true cost of production at small scale. 
My question for starting this thread is strictly out of curiousity. How do companies like Berkshire Products (http://berkshireproducts.com/inventory.php dry slabs that are over 50 inches wide and 4+" think with minimal cracks/checking. What sort of drying protocol might they use? A mix of air dry/vacuum or DH kiln? Large batches or multiple small kilns? What do you guys think? 

[Joey Grimes]

If they are drying 4 inch thick material with no cracks I would bet they are using a vacuum kiln

[low_48]

From Woodfinder.com

"We are a full service lumber business offering custom sawmilling, lumber drying and milling. We have our own sawmill that can saw lumber up to 7' wide and 20 ft long. We have 2 solar kilns and 2 vacuum kilns for drying lumber. For milling we have two 24" planers, a 52" wide 2 Head SCM belt sander plus a Mattison Straight Line rip saw."

[123maxbars]

Not sure on the terminology, but a lot of mills with large budgets are using high frequency radio kilns, if I am saying that right. I have seen videos/pics of green slabs going into those kilns and being bone dry in just a few days with no checking,