The CPU impact is zero; the GPU impact is minor. Winamp's audio engine remains separate, so your FLACs and MP3s will still play with minimal latency.
Visual / Rendering
There is a specific kind of digital magic that happens when you take a piece of software that defined the late 90s and drag it kicking and screaming into the 4K era. For years, Winamp skins were pixel art—tiny, jagged, charmingly low-res bitmaps designed for CRT monitors. But the new wave of "High Fidelity" and vector-based 4K Winamp skins is something else entirely. They don't just update the look; they turn a media player into a piece of desktop art. winamp skins 4k high quality