Before we can do a conclusion, again we give you the overall scores. As you can see the i5 750 is performing almost equally with the i7 920. If you consider the higher turbo, when enabled, then the i5 750 will win. The dual-channel memory interface does not limit the performance. The only "disadvantage" is the disabled Hyperthreading. We think Hyperthreading does not really matter for most consumers. Most applications can't do anything with it and in some applications it will even slow things down. That may change if Windows 7 can organize the cores better, we will see that shorty.
To give you a better overview we have a new chart. We calculated the cost of the used mainboards, CPUs and graphics-card and also the lowest possible price for a 4GB kit for dual-channel or a 3GB kit for triple-channel. Memory of course PC3-12800 (1600MHz) with CL8-8-8-24 and PC2-8500 CL5-5-5-18. So the overclocking memory settings may not apply but it gives you a good overview. The Q9450 is not any more available or at horrible high prices, so we used the Q9550 pricing. As we have written in our AMD Phenom II 965 Black Edition review this CPU is too expensive. You get the best price/performance ratio with an AMD Phenom II 955 Black Edition running on a DDR2 board.
The i5 is the first mainstream CPU based on the Nehalem architecture. While clock for clock the new CPU is faster compared to the Core 2 series and AMD's Phenom II, the new stepping comes close to the power-consumption of the older P45 platform and leaves AMD in the dust. That is also a huge improvement compared to the X58 platform. The CPU will set you back about €174,- that's €50,- less compared to the i7 920.
We also like the flexibility of this CPU. Buying a 2.66GHz CPU and getting over 4Ghz just with air-cooling is impressive. The most amazing is the high under-voltaging capability of this CPU. While you have to disable the turbo mode, you get the same speed with the highest efficiency we have measured yet.
The only problem for Intel is the high platform cost. While enthusiasts are gladly going for DDR3, AMD still has the advantage with its DDR2 platform in terms of value. Not only is the memory cheaper, but the mainboards are also much cheaper. A so called high-end board will set you back under €100,- while the same for the P55 will cost you now about €180,-. Also the integrated chipsets from AMD are miles ahead of Intel, so for office-machines an i5 would be overkill. We will have to see how the cheaper P55 offerings will do. Also the P45 boards are now well under €100,- and the performance is not that far off. For a standard user, who does internet and gaming the cheaper offers will suffice. But we bet the prices will go down and there is a new price war imminent. Intel did however render the i7-920 obsolete, because the i5-750 with Turbo enabled is the faster CPU and platform costs are much lower.
Intel has the upper hand performance wise but on a price/performance ratio AMD win with their DDR2 platform. For many enthusiasts the i5 is a better choice compared to any i7 and also HTPC users who want to use their machine also for gaming can benefit. Therefore, we can easily recommended it.