Think of Intel's quad-core Core i7 processor as a refined Core 2 that's also the beneficiary of Hyperthreading and you're pretty much there. The front-end and execution units are largely the same, except for a few additions to increase efficiency - most notably HyperThreading.
What's really new is the direct-to-memory interface, a high-speed QuickPath link to the chipset, some funky auto-overclocking via Turbo Boost and a new form-factor to accommodate the extra routing pins required for the CPU.
So, in instances where workloads are light the gains, other than from Turbo Boost, are negligible when compared to Core 2. However, add some proper threading in and Core i7 leaves Core 2 in the dust - just take another look at our CINEBENCH, POV-ray, and WinRAR benchmarks for confirmation.
Core i7 is an architecture that works best when really pushed hard, really hard. This is where HyperThreading and, to some extent, the luscious memory bandwidth come into play, posting single-CPU numbers that we haven't seen before and making a Core 2 Extreme QX9770 look aged in comparison.
We can expect workstation and server users to benefit the most from the new architecture because their data worksets will bring out the best in the Xeon iteration of Nehalem. Home users' performance gains will be less apparent, but Core i7's still better than Core 2 in every way.
Knowing this and appreciating that the Core i7 920 will be priced at around £250 when launched later on this month, it makes practically all Core 2 CPUs priced above this level and destined for new PCs kind of redundant, we feel. Why buy expensive, old technology when something newer and cheaper does the trick?
Where does this leave AMD with respect to the home environment? Core i7 doesn't compete against the Phenom X4 line solely because they're so damn cheap. AMD's not likely to win the performance crown back after seeing Core i7 numbers and its pricing will continue to be set by whatever Intel charges for the Core i7 920.
Bottom line: Core i7 is Core 2 with performance cherries on top. On a clock-for-clock basis it can be some 75 per cent faster than the already-potent Core 2 (Penryn) CPU, and it will look increasingly better as more applications are released to take advantage of its eight-threading ability.
If you're a power user who wants to buy a new PC soon, look no further than Core i7. Intel had this market sewn up some time ago but has just double-stitched it with the newest processor in its arsenal. AMD's upcoming Deneb quad-core processor will have to be stupidly good to beat out Core i7.