The behemoth is the model from TFP in Darkness Falls.
Direct storage would allow a lot more zombies in the world, as the CPU has more time to calculate them not beeing busy with loading and processing assets.
You're stretching my memory back 25 years ago to University "Computer Systems Architecture 101"...
I don't think Direct Storage would help that much in terms of computing more actions. CPUs used to need to handle all the interrupts between different components and memory, so slow peripherals tied up the CPU for disproportionate amounts of time. In the original Wolfenstein 3D, you were never surprised by enemies around corners or behind doors, because you could hear the hard disk spin up, and the game would jerk along until the enemy's sprites were loaded. Then the shooting would start!
Direct Memory Access solved a lot of those issues. Direct Storage intends to take it a step further and allow direct communication between SSD and VRAM, without going through System RAM first. But while this speeds up load time, it doesn't really help with freeing up the CPU to do more calculations.
What causes the delay is the sheer number of calculations that need to take place, and the difficulty in running those calculations in parallel. So if you have 64 Zombies, you need to path those 64 zombies in sequence, so you don't have all 64 zombies all trying to occupy the same space. Once you have that figured out, assets are usually already loaded into memory, and memory to video RAM transfer is already very quick, and doesn't take up CPU time.
Don't get me wrong, Direct Storage will help any time you load assets from disk. Moving fast with a wide field of view like from a Gyrocopter would be one example. But doing so doesn't really free up CPU time. Given that you only need to signal that the load has completed, and return an address of where it can be found, the other cores of the processors which aren't busy calculating Zombie jiggle can do this work without interrupting the calculations needed to move Zombies.
I am mostly speculating with probably out of date information from CSA 101, but from what I've read of Direct Storage, it does fit with what I'm seeing other people write about it. I'm looking forward to it, and I really hope it's included in 7d2d. But I wouldn't count on it letting you run any more Zombies.