AMD Phenom II X2 550 vs Intel Core 2 Duo E8400

Gaming speed, cores and clocks

On our gaming index the AMD Phenom II X2 550 scores 8 and the Intel Core 2 Duo E8400 scores 7, about 14% faster for gaming. That gap is small and mostly shows up at 1080p with a very fast graphics card.

The AMD Phenom II X2 550 has 2 cores and 2 threads, and the Intel Core 2 Duo E8400 has 2 cores and 2 threads. Core counts are the same, so cache size and clock speed decide the difference. Boost clocks are 3.1 GHz and 3 GHz.

Platform, power and price

The AMD Phenom II X2 550 uses the AM3 socket and the Intel Core 2 Duo E8400 uses LGA775, so they need different motherboards, and often different memory. When you compare prices, count the board as well as the chip.

Rated power is 80 W for the first and 65 W for the second. That is close enough that cooling needs will be similar.

At launch the AMD Phenom II X2 550 cost $102 and the Intel Core 2 Duo E8400 $183, which gives 7.8 and 3.8 points of gaming performance per $100. Today's prices will differ.

Which graphics cards each one can feed, and which to buy

At 1080p the AMD Phenom II X2 550 can feed a card up to the GeForce GTX 1650 Laptop before it holds the card back by more than 10 percent. The Intel Core 2 Duo E8400 reaches the Radeon R9 380. If you plan to buy a fast graphics card, that gap is the real difference between these two.

Choose the AMD Phenom II X2 550 if you want the faster gaming chip and the same or more cores. Choose the Intel Core 2 Duo E8400 if you would rather spend the difference on a graphics card, which does more for frame rates in most games.