The Relive Instant replay audio will sometimes end up having a slight delay (about 100ms).
I've had this issue since the very first Relive driver.
I have tried this while recording at 720p, 1080p and 1440p. All at 60fps and 50Mbit/s. The audio bitrate is set to 192kbps.
Graphics card: R9 Fury X (Sapphire)
CPU: Core i7 2700K
Motherboard: Gigabyte Z68x uD3H B3 (revision 1.3, latest BIOS)
Ram: HyperX Savage DDR3-1866Mhz 16GB
PSU: Corsair RMx 750W
OS: Windows 10 64bit
Driver version: 17.5.2