Buldozer Vs i3

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 $110 CPU would never accompany a $550 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 $120 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 $110 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-4100	Intel Core i3-2100
Codename:	Zambezi	Sandy 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 MB	3 MB
Thermal Envelope:	95 W	65 W
Online Price:	$110	$125

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.


One of the challenges we face every time we analyze game performance is that most titles offer a large number of customizable graphics settings. Typically, we apply the same settings to every contender. The result is often that low-end GPUs hold performance back when they try to push the same options as the high-end models. Those results end up being unrealistically-low. Nobody plays a game on a Radeon HD 5570 at 12 FPS using the same settings as a Radeon HD 7970.
In order to keep our scores in tune with reality, we're going to try using different settings for each graphics card. How do we choose the right options? Some folks find that, in some games, 30 FPS is perfectly playable, while others won’t take any less than 60 FPS across all of the titles they enjoy. There’s no objective way to choose settings, so we test each game twice, each time using a different performance target.
Our first performance target is a 30 FPS minimum. The video game industry traditionally considers this to be the goal for smooth game play. So, we choose settings that keep the game's minimum frame rate around 30 FPS, but at the highest detail and resolution possible. If you value resolution and visual fidelity over all else, this is the kind of performance target you’re probably shooting for.
The second target is for gamers who want a more fluid experience. In this case, we’re looking for about 60 FPS average, and we don’t want to dip below 40 FPS. This imparts a much smoother feel than 30 FPS minimum, even though we’ll probably have to drop visual settings and resolution to achieve it with lower-end hardware. Gamers who enjoy first-person shooters often favor responsiveness over visual fidelity, especially in competitive environments.
Our FX-4100 is actually an FX-8120 with two of its Bulldozer modules turned off. We've run exhaustive testing against an actual FX-4100 to confirm that the performance is similar. The only complication is a lack of granularity in setting its Turbo Core multiplier. So, the CPU itself runs at 3.8 GHz (rather than ranging between 3.6 and 3.8 GHz). With that established, a 100 or 200 MHz difference isn't going to impact our results noticeably.
Finally, we want to point out that the $125 Core i3-2100 is only $3 less than the Core i3-2120, a CPU that is 200 MHz faster. Although the -2120 would be our recommended buy, we're using the -2100 because that's what we have on-hand.

				Socket AM3+	LGA 1155
CPU				AMD FX-4100 (Zambezi), 3.6 GHz Base, 3.8 GHz Turbo Core	Intel Core i3-2100 (Sandy Bridge), 3.1 GHz, Hyper-Threading enabled
Motherboard				Biostar TA990FXESocket AM3+, Chipset: AMD 990FX	Asus P8P67 Pro LGA 1155, Chipset: Intel P67 Express
Networking			On-Board Gigabit LAN controller
Memory			Corsair Vengeance LP PC3-16000, 2 x 4 GB, 1600 MT/s, CL 8-8-8-24-2T
Graphics			AMD Radeon HD 5570 650 MHz GPU, 1 GB DDR3 at 900 MHz AMD Radeon HD 6770 850 MHz GPU, 1 GB GDDR5 at 1200 MHz AMD Radeon HD 6850 775 MHz GPU, 1 GB GDDR5 at 1000 MHz AMD Radeon HD 6950 800 MHz GPU, 1 GB GDDR5 at 1250 MHz
Hard Drive			Western Digital Caviar Black 750 GB 7200 RPM, 32 MB Cache, SATA 3Gb/s
Power			ePower EP-1200E10-T2 1200 W ATX12V, EPS12V
Software and Drivers
Operating System			Microsoft Windows 7 x6, Service Pack 1, KB2645594 and KB2646060 installed
DirectX			DirectX 11
Graphics Drivers			AMD Catalyst 12.1

Benchmark Configuration
3D Games
Metro 2033	Version 1.0.0.1, Built-In Benchmark
Battlefield 3	Version 1.0.0.0, Operation Swordbreaker, FRAPS runs
Elder Scrolls V: Skyrim	Version 1.4.21.04, FRAPS runs
DiRT 3	Version 1.2.0.0, Built-In Benchmark
Just Cause 2	Version 1.0.0.2, Concrete Jungle Benchmark
StarCraft 2	Version: 1.4.2.20141, Tom's Hardware Guide Benchmark Performance Target: 30 FPS Minimum Battlefield 3 was obviously limited by the performance of our Radeon HD 7970 the last time we tested it. As such, we don’t expect our choice in processors to have much effect on the frame rates of our configurations. In the first round, our target is a 30 FPS minimum frame rate: Only AMD's Radeon HD 5570 has to be forced under 1080p to hit our minimum target; we set it to run at 1280x720. Every other graphics card achieves our goal at 1920x1080. And, as expected, there is little to no difference between CPUs as we step up from entry-level to mid-range graphics setups. The Core i3-2100 does manage a marginal lead with AMD's Radeon HD 6770, but nothing you'd notice during game play. Unfortunately, while we see minimum frame rates that look good, the averages are very close to 30 FPS, too. So, let’s aim for a 40 FPS minimum and closer to 60 FPS average and see what happens. Performance Target: 40 FPS Minimum, 60 FPS Average This time we had to drop the Radeon HD 5570 to 800x600 to achieve our target. The Radeon HD 6770 dips to 1680x1050. Both the Radeon HD 6850 and 6950 are able to handle 1080p. Even at our lower settings, the choice of CPU doesn't affect the outcome in an appreciable way. In fact, the FX-4100 scores marginally better using the Radeon HD 6850, although the advantage is not significant. Overall, we're not surprised by the outcome of our Battlefield 3 charts. After all, even AMD's powerful Radeon HD 7970 couldn't shift enough of the game's workload to our CPUs to expose a weak link.