Is this just another APU from AMD? Not quite. The A10-7800 has a different purpose than the flagship -7850K, and that's good news. AMD found the right spot between moderate performance and modest power consumption. As a result, the A10-7800 is a winner if you're building a well-balanced, low-cost PC where price, performance, and efficiency are well-balanced. Yes, you could easily build a faster system using a CPU and discrete graphics card, but it'd almost certainly pull more power from the wall, and would probably be pricier, too.
That combination of attributes, culminating in commendable efficiency, is the A10-7800's unique selling point. You get this from AMD's factory settings. As a result, we don't believe that attaching discrete graphics is a good idea. If gaming is your bag, then find a dedicated host processor and build from there. Otherwise, you're losing the APU’s only advantage, while suffering the compromises of a multi-GPU machine. Besides that, you’d affect the price/performance equation in a negative way. For instance, compare the power draw of a Radeon R7 250 with this APU. The processor gives you a comparably-fast graphics engine with x86 cores thrown in at lower consumption levels. This earns the A10-7800 our Tom's Hardware Smart Buy recognition. If you're considering an APU, the -7800 is the family's purpose-built solution (more so than the -7850K or -7700K).
And of course, if you yearn for high efficiency, the other system components also matter. This APU isn't cheap, and it's too easy to jeopardize those balanced figures we measured with platform parts that aren't complementary. An Athlon X4 760K and Radeon R7 250 would cost about the same. The APU is self-contained, though. And because it takes up less room, your case can be both smaller and easier to cool. The A10-7800 sets itself up to be the engine at the heart of a truly compact entry-level computer.
For such an application, you'd probably want a well-built mini-ITX motherboard. Short of that, MSI's A88XM Gaming proves itself to be an energy efficient microATX alternative, drawing a mere 4-8 W. It's armed with a feature-rich BIOS that lets you optimize the APU's behavior further. Given a shortage of exemplary Socket FM2+-based boards, we're glad we picked this one for our experiment.
If you want to build a home theater or general-purpose PC for casual gaming and office work, the A10-7800 is a smart choice. Just add fast memory (to feed the graphics engine) and a good motherboard. AMD hits the sweet spot, closing the gap between its A10-7700K and -7850K.
In fact, the A10-7800 is an even better option than the -7850K, since that APU's slim performance gain comes at a significant cost to efficiency. You won't notice the -7800's slightly lower performance. What you should be impressed by is the fact that we ran the whole system, including a 480 GB SSD, from a diminutive DC-DC converter and an efficient external AC adapter rated for 65 W. With the addition of a closed-loop liquid cooler, the system draws less than 55 W at the wall. I think it's possible to get below 50 W with an air cooler and some more tweaking. That's an amazing feat and a welcome surprised from a company commonly critiqued for power-hungry processors.