Coming soon: hard drives with 1GB+ DDR RAM cache →
https://marco.org/2007/09/03/coming-soon-hard-drives-with-1gb-ddr-ram-cache
This is almost really cool. But ditch the 2.5” 5400 RPM drive and do whatever it takes to use a real 3.5” disk. Your crazy RAM and additional circuitry can fit on the standard bottom circuit board with plenty of room to spare.