Pretty sure your CPU is tiers faster than even the best laptop CPU for what you're doing. Your issue is elsewhere.
Loading several images from slow HDD's, especially those being served through a RAID 1 array, will be slow. That's your #1 bottleneck. That has to be read and served through the bus to the RAM for use. Your bottleneck is between the data itself and how it gets to your RAM.
Except where the OP states this:
The HWMoniter app shows all the PC cores pegging at 100% the instant I send images to a HDR app. It takes 3-5 minutes to do a HDR. A friend of mine just got a relatively inexpensive laptop and the same process takes 20-30 seconds with that laptop.
A RAID1 array isn't necessarily slow. I can have a pair of Samsung 850Pro SSD drives in RAID1, and it'll be more than fast enough. If the CPU utilization is pegged at 100%, the CPU(s) are the bottleneck. If your RAID implementation is software based, through the O/S, then that processing is handled by the CPU also, making the situation worse.
I have a quad-core, hyperthreaded i7 laptop with 256Kb L1 cache, 1MB of L2 cache, and 6MB of L3 cache, with 24Gbs of RAM, and 2TB of SSD storage, and it does everything immediately.
OP, sounds like a new motherboard and CPU combo, and most likely new memory are in your future. You don't absolutely have to re-install your O/S, but I would. Also, if you can (and I would highly recommend it), get a dedicated RAID controller, so the controller on the card handles the RAID functions, rather than the host CPU.