This time we'll start with only a brief introduction to theory: we learnt about the ideas behind the AMD K10 core and Phenom processors long before these processors appeared, several years ago actually. Many technically literate users (not only apostles of this company) were looking forward to these processors. They had all grounds to expect (at least theoretical) interesting, if not supreme results: victories (at least owing to the expanded floating-point unit and native quad-core design), parity, and sometimes defeats. But results must be competitive. Our competitors have different approaches to architecture with their own trump cards.

After the rollout of Phenoms, which results were apparently below the expected level, a lot of users wondered about the reasons. Later on we got used to the situation. Moreover, Phenom processors are quite popular now, and many users are pleased with them. In the course of price wars these processors got attractive price tags that really reconciled users with this performance level. Phenom II processors do not promise many performance-related improvements, as we found out long before the launch of these products: three times as large L3 Cache and higher frequencies owing to the 45-nm fabrication process. However, there are some mentions of architectural optimizations. If such announcements were made about an old streamlined processor core, squeezed dry after many revisions, we could hardly expect anything interesting. But in this case we may hope that such measures may be sufficient to reveal the true potential. Let's see what we've got here.

We've tested a top model (3.0 GHz) with the unlocked multiplier. The manufacturer also offers a processor with Index 920 (2.8 GHz). These are Socket AM2+ CPUs, that is they are designed for the Phenom platform. Motherboards just need a proper update -- most manufacturers released them back in October-November, last year.

The recommended price for Phenom II X4 940 is $275, so its apparent competitor in our tests is Core i7 920, which recommended price is higher only by $5. We speak of the configuration used in our tests, Turbo Boost and Hyper-Threading enabled. You may find that it's not fair to use automatic overclocking, because Phenom also has an overclocking potential and allows to control its core multipliers individually. But this factor is counterpoised by 3 GB of memory, while the other processors are tested with 4 GB. Our objective is to provide test conditions as close to real as possible. And owners of Core i7 will hardly disable Turbo Boost. Moreover, they will certainly try to use the three-channel controller. But only users of the extreme model may agree to fork out for the 6-GB kit right away.

We should keep in mind that the platform (including a motherboard and memory) is too expensive for Core i7 now even with this limitation. So most users will probably compare Phenom II with much more popular Core 2 Quad. Thus, the second rival in our tests is a processor based on Yorkfield (Q9300). From a reviewer's point of view, it's really interesting to see how the new top model fares against top CPUs from the Phenom series (9850) and competing processors based on Kentsfield core (Q6600). Besides, dual-core processors still demonstrate acceptable performance in a number of tests, sometimes they even perform on a par with more expensive quad-core processors. However, it's not quite correct to compare these results directly. To be more exact, they are true for synthetic (sterile) conditions of our testbeds, when both cores of a dual-core processor can be assigned to execute the test. In reality, background processes interfere with tests (their data in cache) in the very least, or even consume much resources. On the other hand, Phenom, Phenom II, as well as Core i7 (especially models with the unlocked multiplier) have an excellent capacity for selective overclocking of their cores, so it's very easy to turn them into high-quality dual- or triple-core processors, if necessary.

Testbed configurations

* The maximum frequency supported by the memory controller in a processor; you can choose a lower frequency, if it's supported by a given memory standard (for example, DDR2-667 and DDR2-800 for processors supporting DDR2-1066); frequency and memory type of LGA775 processors are detected by the chipset.
** Unlocked so that users could increase it for overclocking.
*** When Turbo Boost is enabled (by default), the real clock rate of separate cores grows to 2.8-2.93 GHz depending on the current load, so it's not correct to compare this value with fixed clock rates of the other processors directly.

• Memory: 4 GB (3 GB for Core i7 920)
• HDD: Samsung HD401LJ (SATA-2)
• Coolers: Thermaltake TMG i1, TMG a1
• PSU: Cooler Master RS-A00-EMBA