here, toms' review of ivb (core i7 3770k). it provides a lot of info on ivy bridge cpus.http://www.tomshardware.com/reviews/ivy-bridge-benchmark-core-i7-3770k,3181.html
ivy bridge cpus are just an incremental upgrade over sandy bridge cpus. general difference between sb and ivb cpus are -
sb cpus are manufactured on 32 nm process, ivb cpus are manufactured on 22 nm process.
ivb arch is a tweaked die shrink of sb architecture.
ivb cpus generally have lower tdp than sb cpus. this means ivb cpus use less power on load than sb cpus doing the same task.
ivb cpus have newer, upgraded, more tweaked igpu (integrated gpu) such as hd 4000 and hd 2500. sb cpus have earlier gen hd 3000 igpus and hd 2000 igpus.
ivb cpus (so far, core i5 and i7 only) have integrated pcie gen 3.0 controller while sb cpus(all except sb-e cpus) have pcie gen 2.0 controller.
ivb igpus have open cl support and dx 11 hardware support. sb igpus don't have open cl support and supports up to dx 10.1.
ivb igpus have upgraded quick sync 2.0 opposed to sb's quick sync 1.0.
most of the upgrades went to ivy bridge's igpus. cpus received minor tweaks.