And
then now the calculations: If the Prescott can have 256 uOps in
fly then it should be a factor 256/126 larger.
Further
more. If the RF(s) have 256 entries then the pointers grow from 7 to 8
bit, making it an extra factor 8/7 lager. So, If Northwood's RAT
history table would linearly scale from 0.349 mm2 with a factor (9/13)^2
to 0.167 mm2then we want to see a Prescott version with a size of more
or less 0.167 mm2 * 8/7 * 256/126 = 0.388 mm2
Calculated
versus Measured is 0.388 mm2 : 0.379 mm2 giving a ratio of
1.023
That
is very close indeed given assumed linear scaling from 130 nm to 90 nm,
cutting out vague blue and artificial colored rectangles
and the not entirely correct assumption that memories scale in size
proportional with the number of entries or
bits. ( We should suspect that error in measurement is
significantly larger then the 2.3% so we must have had some luck here )
