Lpc2000

Hi guys, 
I am finding it a little tricky to calculate how fast this chip can
actually go for my app. (Instruction cycles and MAM) 

I was wondering if anyone can tell me how fast it would execute this
code at 60MHz:

Read in 16 bits from port1
store in RAM
increment pointer
loop for N times

I basically want to buffer data as fast as possible in bursts. Ideally
at 20MHz.

How much faster would it execute in RAM. 
Could I make it faster by using an infinite loop and using a timer to
'break out' of the loop.

Mark.