Since R9 270x Vapor-X 2GB uses DVi-D [dual link] port, it's gonna be great. You can hook her up either on digital, or analogue [vga] LCD panel without any issues.
Just try to use higher quality analogue cable, with ferit endings, ferit shielding and golden coating. The same goes for adapter. Try to get one that is built in ferit body, with golden coating. Analogue signal is kind of squeamish, or delicate towards environmental interference, so it requires higher standart of cables/adapters/convertors, to achieve good results.
P.S.: After connecting it to the LCD panel [monitor], don't forget to use the "auto" function on Your LCD panel [monitor]!