Best Of

Is there a specific reason you want to add a Xonar? Drop that and add the $30 to your video card budget to get something like an R7 360. If you have a spare $10 you could find an RX 460 for around $100.

I'd suggest getting the cheapest name-brand DDR3 you can find. This is on sale: https://www.newegg.com/Product/Product.aspx?Item=N82E16820226398

You very well may. Vsync can buffer up to 3 frames, depending on how it is implemented. So if you're running at 60 FPS (16ms), events you're reacting to on-screen and/or server updates may not be rendered out to your eyeballs for n+3 frames... or a full 48ms later. The potential perils of vsync!

I'm thinking about getting a 1600X or 1500. The 1600X is a 95W part, and the 1500 is 65W.
If I don't OC the 1600X, would it actually use much more power than the 1500? Would it likely get close to the 95W rating?

My main interest is switching to a compact and quiet mATX system, so I'd want to keep cooler size and noise down.

Leaked benchmarks have the single threaded performance of the 1600X to be 31% better than my 2500K, and 143% better multithreaded performance. Finally, a significant upgrade from Sandy Bridge for less than the retail price of Sandy Bridge when it was new!