http://semiaccurate.com/forums/showthread.php?t=7006
My comments after skimming through the Tom's Hardware article (in addition to linked post):
- memory & L3 performance looks lower,
- L1 bandwith 2x higher as promised,
- GT2 in Haswell noticeably faster than HD 4000 - it suggests that GT3 that will come to laptops will bring a huge speedup and can make mobile AMD APU's look silly,
- Haswell is mainly about optimizations for laptops (ie power) and AVX2, which seems a bit weird combination for me,
- speedup is very small on single threaded workload, more on multithreaded ones - this suggests that they improved HyperThreading scalability,
Power draw measures haven't been posted but Intel has promised much lower power consumption.
Overall, to recap:
- very low improvement in high-end chips - not worth to wait,
- probably big improvement in low-power chips,