Clocked at 3.2GHz with a 2.0GHz un-core (or North Bridge) frequency, the 955 isn’t that much different from the 940 in terms of clock speed. The two face off in the table below:
| CPU | Clock Speed | un-core Clock (NB Frequency) | Die Size | Transistor Count | TDP | Socket |
| Phenom II X4 955 | 3.2GHz | 2.0GHz | 258 mm2 | 758M | 125W | AM3 or AM2+ |
| Phenom II X4 940 | 3.0GHz | 1.8GHz | 258 mm2 | 758M | 125W | AM2+ |
This is a Socket-AM3 part, meaning it can work in both DDR2 based Socket-AM2+ motherboards and DDR3 based Socket-AM3 motherboards. There’s a huge compatibility caveat about AM2+ support but I’ll address that shortly. The Phenom II X4 955 is also a Black Edition part, meaning it has an unlocked clock multiplier for easy overclocking.
Along with the 955 there’s also a 945 being introduced today. The 945 is identical to the 940 in core clock speed but has a 2.0GHz un-core and is also AM3 compatible.
| Processor | Clock Speed | un-core Clock | L2 Cache | L3 Cache | TDP | Price |
| AMD Phenom II X4 955 BE | 3.2GHz | 2.0GHz | 2MB | 6MB | 125W | $245 |
| AMD Phenom II X4 945 | 3.0GHz | 2.0GHz | 2MB | 6MB | 125W | $225 |
| AMD Phenom II X4 940 BE | 3.0GHz | 1.8GHz | 2MB | 6MB | 125W | $225 |
| AMD Phenom II X4 920 | 2.8GHz | 1.8GHz | 2MB | 6MB | 125W | $195 |
| AMD Phenom II X4 910 | 2.6GHz | 2.0GHz | 2MB | 6MB | 95W | $??? |
| AMD Phenom II X4 810 | 2.6GHz | 2.0GHz | 2MB | 4MB | 95W | $175 |
| AMD Phenom II X4 805 | 2.5GHz | 2.0GHz | 2MB | 4MB | 95W | $??? |
| AMD Phenom II X3 720 BE | 2.8GHz | 2.0GHz | 1.5MB | 6MB | 95W | $145 |
| AMD Phenom II X3 710 | 2.6GHz | 2.0GHz | 1.5MB | 6MB | 95W | $125 |
| AMD Phenom 9950 | 2.6GHz | 2.0GHz | 2MB | 2MB | 140W | $173 |
The prices are pretty attractive; the 955 will sell for
$245 (and it already has been) and the 945 will go for $225. That pits the 955 against Intel’s Core 2 Duo Q9550 ($266) and the Core i7-920 ($284), the latter having a much higher motherboard cost of course.
| Processor | Price |
| Intel Core i7-920 (2.66GHz) | $284 |
| Intel Core 2 Quad Q9650 (3.00GHz) | $316 |
| Intel Core 2 Quad Q9550 (2.83GHz) | $266 |
| Intel Core 2 Quad Q9400 (2.66GHz) | $213 |
| Intel Core 2 Quad Q8400 (2.66GHz) | $183 |
| Intel Core 2 Quad Q8300 (2.50GHz) | $183 |
| Intel Core 2 Quad Q8200 (2.33GHz) | $163 |
And you know how I love spoiling surprises so here you have it. Unless you’re running applications that are very well optimized for Intel’s architectures, the Phenom II X4 955 is faster than the Core 2 Quad Q9550. Compared to the Core i7-920, it loses hands down although the chip does come close in some games.
