I find that both NAND FLASH and flip-flops are made up of NAND gates. The only difference between them is NAND FLASH uses floating gate transistors to store charge.
Your Flash drive is actually made up of NAND FLASH and cache memory which has speed equivalent to CPU is made up of flip-flops.
My question is if both operates at 5V and both are made up of basic cell unit NAND gates then what makes flip-flops so faster than Nand-flash? Or What makes Nand-flash slower than flip-flops (probably due to floating gate transistors?) ?
In other words what makes cache memory so faster than a flash drive? The drift velocity of charge in both the architecture must be same as 5V is used for them.