The technical mechanism of the plugin was deceptively simple. It was not a codec built into Nero’s core, but rather a Dynamic Link Library (DLL) that acted as an intermediary. When Nero requested audio data from a file, the plugin intercepted the request, decoded the FLAC stream in memory back to raw PCM (Pulse-Code Modulation), and fed that uncompressed data to Nero’s burning engine. To the user, the experience was seamless; under the hood, it was a real-time translation layer. However, this approach had limitations. Because decoding happened on the fly, performance depended heavily on CPU speed. On the single-core Pentium 4s and AMD Athlons of 2006, burning a CD from high-resolution FLAC files could sometimes lead to buffer underruns, resulting in a "coaster" (a ruined disc). Power users learned to burn at slower speeds (4x or 8x) to compensate.