I have a hunch that you're splitting a hair that is so super-fine that it's invisible... To do any processing, a CPU needs data... in and out
One analogy that I like is the location of ingredients in a kitchen...
On-board cache is like one of those tiny herb and spice racks... within easy (pretty much instantaneous) reach of the chef. Because it's so very, very small, a galley slave needs to be both very clever and super diligent when accommodating/anticipating the demands of the chef
RAM is much, much bigger... but also much, MUCH further away... sorta like a pantry/larder that is (ideally) stocked with big boxes full of the sort of ingredients that have been used lately... the sorta stuff that will probably be used again soon... But... it's down in the hold, so going to-and-fro is a bit of a drag for the galley slave, who has a limp
The hard drive is immense, like a warehouse full of every ingredient ever used but... it's 20,000 leagues across the sea... and the Nautilus is in dry-dock... so the galley-slave has to swim for it
I very much doubt it (unless your definition of "
much more like" is as vague as a very vague thing

), simply because - no matter how quickly the data comes in to port - there's still only so much room on the kitchen bench
Thanks for the link... but...
Although there has been significant progress in terms of capacity, they're not exactly 'new' (hence some of my confusion)... and, although data-transfer rates are much faster than from hard-drives, it occurs to me that this is still data-
transfer, to the on-board cache...
So how will SSDs broaden the bottleneck?