Tri-core CPUs have emerged as a differentiating product for AMD — Intel can't build CPUs with three individual cores yet. However, the company will have to re-think its pricing strategy if it wants to attract new PC builders and users looking to upgrade their existing systems.

At the time of writing, street pricing for the Phenom X3 8750 averaged $250, which was approximately $100 less than the equivalent-frequency Phenom X4 9750 quad-core CPU; and it was not at all competitive against Intel's Core 2 Quad Q6600 quad-core CPU, which could be found for only about $30 more at $280. This means that the X3 is unlikely to gain AMD any new users, but existing AMD platform users might find it a decent upgrade if they don't have the extra $100 needed to for an X4 chip.

However, it's worth noting that it's not guaranteed to work on all motherboards, so users should make sure they check their motherboard vendor's Web site for support. While the CPU itself is based on the AM2+ CPU socket, most motherboards with an older AM2 socket should still be able to run it but won't be able to harness the CPU's faster 3.6GHz HyperTransport speed, and instead revert to 2GHz.

The X3 8750 is comprised of three individual CPU cores, each running at 2.4GHz and each with its own 512KB L2 cache. A 2MB L3 cache is shared between all the cores; the L2 cache acts like a buffer between the cores and the L3 cache so that they don't all try to query it at the same time. It has an integrated DDR2 memory controller, too, with support for module speeds up to 1066MHz, and it also has a HyperTransport 3.0 interface, which can provide up to 16GBps bandwidth between the CPU and motherboard chipset.

In fact, it's identical to the Phenom X4 9600 in its architecture — the only thing that's different is that it has one less core and a slightly higher frequency (2.4GHz as opposed to 2.3GHz). Even the X4's and X3's thermal characteristics are identical — 95W — as the Phenom X3 is also built using AMD's 65nm (nanometre) manufacturing process.

To give you an idea of how much power the Phenom X3 will consume in a regular PC, we measured its electricity draw from the power outlet. Using a Seasonic 900W power supply, a Gigabyte GA-MA790FX-DQ6 motherboard, 2GB of Corsair DDR2 800MHz RAM, a 750GB Seagate Barracuda ES hard drive, an ATI Radeon HD 2600Pro graphics card and an ASUS Serial ATA-based DVD burner, the system consumed about 150W when idle, and 190W when under a maximum 3-D rendering load. On the same system, the Phenom X4 9600 consumed 197W when under a maximum load.

You could also use AMD's Power Monitor software (you can download it from AMD's Web site) to consume less power by using a low-power or balanced profile. In a balanced profile, the idle speed of the CPU is cut to 1.2GHz, and it will only run at 2.4GHz when the CPU's load increases. It works very well.

In our performance tests, the X3 8750 scored 93 in WorldBench 6, which is better than the X4 9600's score of 90. This is due to the X3's slightly faster frequency. In the iTunes test, where we convert 53min worth of WAV files to 192Kbps MP3s, the X3 was faster than the X4 by one second (1min 23sec compared to 1min 24sec). So you can see that if straight-line speed is required, and cores don't matter, the X3 is actually quite fast. But its three cores also keep it competitive when it comes to running multithreaded software and, of course, multitasking.

In the 3-D rendering test, using Blender, which is a multithreaded application, the X3 was able to render three threads simultaneously and complete the job in 59sec. The X4, with its extra core, completed the same job in 48sec using four threads. Incidentally, when we ran four threads on the X3, it completed the rendering task in 57sec.

So there's no question the extra core will come in handy if you're currently a dual-core AMD user with a bent for 3-D rendering and video editing and can't afford to buy a quad-core Phenom, but for Intel users, this isn't a sweet enough CPU to warrant changing platforms.