Motherboard, Graphics, And Power
It’s keepin’ me waitin’…
Motherboard: Gigabyte Z77X-UD4H
After initially considering the Z77-HD4 for an early project, I had grown dubious of the voltage regulator previously found on my problematic Z77X-D3H-based machine. But when the motherboard we initially picked for this build failed as well, I had to circle back, look closer, and search for issues responsible for killing the parts we were buying.
Instead of the UD3’s tiny five-phase regulator, we instead find a 12-phase design that’s a closer match to Gigabyte's venerable UP5 TH implementation. With questions of capacity out of the way and an advanced feature set worthy of its higher price, we were happy to make the switch. We’ll discuss why our initially-chosen Z77 Extreme4 was later replaced shortly.
Video Card: 2 x PowerColor PCS+ AX7870 Myst Edition
If one Tahiti-LE-based graphics card is good, then two must be better, or so goes the idea behind the GPU performance upgrade in today’s widely-upgraded build.
Axial fans blow GPU heat into our case, and dual GPUs compound the problem of that heat rising into the CPU cooler. Our oversized Noctua heat sink will maintain our overclocking goals in spite of this problem, allowing us to use this pair of top-value cards, even though we'd typically frown on such a thermal configuration.
Power Supply: Corsair HX750
I understand the difference between input and output power, yet still had no idea that our $1,000 PC’s 520 W power supply would prove vastly overkill for a system that topped out around 340 W (calculated output at 85% efficiency).
Those results technically leave enough capacity to power a second graphics card. However, the Antec PSU I was using doesn't have enough connectors to drive my second PowerColor board.
The good news is that I got excess capacity from Corsair HX750 for free, at least compared to other 80 PLUS Gold-rated units of similar quality. Seasonic’s X650 Gold, for example, was listed at the same price. And smaller high-end units didn’t give me enough auxiliary PCI Express connectors.