AMD FX Vs. Intel Core i3: Exploring Game Performance With Cheap GPUs

Following our sub-£160 gaming CPU comparison, we put Intel's Core i3-2100 and AMD's FX-4100 under the microscope. This time, we test a number of different graphics cards from AMD to see how GPUs affect perceived processor bottlenecks.

At the end of January, we published our analysis of the sub-£160 gaming processor market called Picking A Sub-£160 Gaming CPU: FX, An APU, Or A Pentium?. We were surprised to find that Intel’s budget-oriented LGA 1155 offerings are surprisingly capable when it comes to handling modern titles. In fact, the £90 Core i3-2100 beat out AMD's entire line-up including top-tier Phenom IIs, Athlon IIs, APUs, and even the new FX models. Although they're easier to overclock, AMD’s best efforts could only achieve parity with the Core i3-2100, and Intel's Core i5 was so far ahead of the sub-£160 pack that it sat in a league of its own.

Now, we used a very high-end Radeon HD 7970 graphics card in that article because we wanted to isolate CPU performance. You can't draw conclusions about a CPU's potential when you're faced with a graphics card bottleneck, after all. But some of our readers rightly pointed out that, when it comes to building an inexpensive machine, our combination is unrealistic. A £90 CPU would never accompany a £450 graphics card. And if we used an entry-level GPU, the resulting bottleneck would have masked the differences between processors to a greater extent. The counter, of course, is that a cheaper graphics card would have also imposed lower resolutions and detail settings, shifting load back in the direction of the CPU.

As you know, though, we put a big emphasis on addressing your feedback, so we went back to the lab to run some follow-up data on two of the most interesting £90 options from our previous story. Intel's Core i3-2100 is the low-cost processor to beat, so we made sure to include it. On the other hand, with AMD's Phenom II and Athlon II lines disappearing from store shelves, the £90 FX-4100 represents that company’s best low-priced option.

Every game's workload is different, but Intel’s i3-2100, on average, achieved 18% higher minimum frame rates and 11% higher average frame rates compared to the FX-4100 in our previous story. As we said, though, that was with a Radeon HD 7970. This time around, we’re using a broader range of graphics cards ranging from the Radeon HD 5570 up to the Radeon HD 6950 to see if the bottleneck situation changes.

AMD FX-4100Intel Core i3-2100
Codename: ZambeziSandy Bridge
Process: 32 nm 32 nm
Cores (Threads): 4 (4)
2 (4)
Clock Speed (Turbo): 3.6 (3.8) GHz
3.1 GHz
Interface: Socket AM3+LGA 1155
L3 Cache: 8 MB3 MB
Thermal Envelope:
95 W
65 W
Online Price:

We also received some feedback on our test platform's memory configuration; it was suggested that AMD's FX might perform better complemented by higher memory data rates. So, this time we're using 8 GB (2 x 4 GB) of Corsair Vengeance DDR3-1600 at 8-8-8-24 timings.