Does Your System Have What It Takes?
Making Sure You Support The Radeon R9 295X2
Not surprisingly, a ~500 W graphics card attached to rubber hoses and a radiator requires a couple of special considerations. Mainly, your chassis needs to be large enough with the necessary mounting points, and your power supply must deliver ample current.
Right out of the gate, AMD’s Radeon R9 295X2 is a long card (it’s 12-inches in length, like the Radeon HD 7990), so you can’t cram it into compact enclosures. But now you also need room to mount its radiator and fan as an exhaust. A great many chassis have at least one spot for a 120 mm fan, so this shouldn’t be an issue. But if you’re also using a closed-loop CPU cooler, you actually need two positions able to take a radiator.
Rosewill sent us a couple of its Throne enclosures to use in the lab, and they served as my platform for testing. I already had an Intel BXRTS2011LC blowing out the back, and needed to mount the 295X2’s radiator up top. In every orientation but one, Asetek's solution interfered with the voltage regulator heat sink on my MSI X79A-GD45 Plus. Of course, I have plenty of hardware here in the office to swap in or out, but the Radeon R9 295X2 came really close to not working with the first configuration I set up.
Not an issue in the Throne, but something else to think about is the fact that you have about 380 mm of tubing to work with, which could become in an issue in a particularly tall chassis. The same concern applies to the second card in a quad-GPU configuration. Of course, that’d also require a third mounting spot as well.
AMD is more specific when it comes to power supply compatibility. Clearly, you need two eight-pin auxiliary connectors, and the company suggests avoiding adapters to create eight-pin blocks. Each one needs to be capable of delivering 28 A of current, and a combined 50 A beyond the rest of the platform’s draw on the +12 V rail.
As you might imagine, this is a really good time to own a power supply with a single +12 V rail. If yours uses multiple rails, the next step is to figure out how your connectors share them, taking care to truly reserve the right amount of current for AMD’s card.
The company doesn’t call out a recommended power supply capacity in its press material, instead choosing to get specific about amperage. But if you’re setting aside an aggressive 550 W for the Radeon R9 295X2 and you have an overclocked Ivy Bridge-E-based CPU, memory, storage, and a handful of cooling fans, anything under 1000 W starts looking a little dicey.
