Platforms And Overclocking
Before diving head-first into the performance data, let’s cover the platforms we used to test and the overclocks those components achieved.
Socket AM3+: Gigabyte GA-990FXA-UD3
As a budget-oriented piece emphasizing overclocking, we wanted affordable hardware with enthusiast-friendly features. Gigabyte's GA-990FXA-UD3 Socket AM3+ motherboard fit the bill for testing our FX, Phenom II, and Athlon II processors.
Based on the AMD 990FX/SB950 chipset, the board packs a ton of connectivity, including six SATA 6Gb/s ports, USB 2.0, USB 3.0, eSATA, and FireWire. We're able to appreciate the company's Ultra Durable 4 technology suite, 8+2 phase power design, solid capacitors, and dual BIOS chips in case something goes wrong while we're overclocking.
Socket FM2: Gigabyte GA-F2A85X-UP4
Next, we chose the feature-rich GA-F2A85X-UP4 for testing our Athlon X4 750K. Based on AMD’s A85X Fusion Controller Hub, this enthusiast-oriented Socket FM2 board is built for APU tweaking. It sports Gigabyte’s Ultra Durable 5 technology, again, solid capacitors, and a beefy power stage rated at 60 A.
A trio of PCI Express x16 slots accommodate up to two graphics cards at x8 and x8 transfer rates. The platform also supports Dual Graphics, though we wouldn't recommend going that route. Four DDR3 memory slots support dual-channel configurations at up to 2400 MT/s. Here, again, you get ample connectivity via six USB 3.0 ports, seven SATA 6Gb/s connectors, and one eSATA 6 Gb/s interface. Other notable features include dual BIOSes, Lucid Virtu Universal MVP GPU virtualization, and 3x USB Power with On/Off Charge technology.
Overclocking
Given the flexibility of these CPUs, I took a slightly different approach to overclocking than I would in an Intel-focused story. In my prior piece, I knew the chips in question offered quite a bit of headroom, so I picked frequencies that'd be easily attainable for most folks. Capping the clock rates low helped represent commonly-used settings.
In contrast, AMD's processors ship at clock rates that leave little headroom with their boxed heat sinks and fans. So, I used the same Xigmatek setup that took Intel's Wolfdale architecture to 4.5 GHz. It made sense in this value-oriented experiment to keep aftermarket cooling in the $20 to $30 dollar range. Then I doubled up on component airflow by adding a second 120 mm fan to avoid VRM-related throttling. Although I chose not to push crazy voltages, I did tweak the CPU-NB frequencies, and squeezed everything I could (within reason) from each setup, while respecting the thermals.
Die-hard enthusiasts from both camps might be crying foul, wondering why I pushed AMD's chips harder or shied away from larger air coolers. The bottom line is that we're evaluating the performance of inexpensive CPUs and stacking them up relative to each other. I suspect that the AMD crowd is going to push its chips just as hard, and with good air circulation and a respectable heat sink, you shouldn't have any trouble achieving results like mine.