The backup was running on an E6400, so:
Much more l2 cache
12 MB
vs
2 MB
6x more l2 cache; more data can be stored in the l2 cache for quick access later
Significantly higher clock speed
3.16 GHz
vs
2.13 GHz
Around 50% higher clock speed
Much newer manufacturing process
45 nm
vs
65 nm
A newer manufacturing process allows for a more powerful, yet cooler running processor
Much more l2 cache per core
3 MB/core
vs
1 MB/core
3x more l2 cache per core
Much better geekbench 3 Multi-Core score
7,123
vs
2,071
Around 3.5x better geekbench 3 Multi-Core score
Supports more CPUs in SMP configuration
2
vs
1
Twice as many CPUs in SMP configuration
Better PassMark (Single core) score
1,335
vs
801
More than 65% better PassMark (Single core) score
More cores
4
vs
2
Twice as many cores; run more applications at once
Better overclocked clock speed (Air)
4.06 GHz
vs
3.33 GHz
More than 20% better overclocked clock speed (Air)
More threads
4
vs
2
Twice as many threads