XFX Radeon RX 6600 XT Speedster Merc 308 Review

W1zzard

on Aug 11th, 2021,

in Graphics Cards.

Manufacturer: XFX

Value & Conclusion »

Overclocking

GPU-Z Screenshot for Overclocked Graphics Card

Overclocking the Radeon RX 6600 XT is quite complicated. You must increase the power limit or you won't see any performance gains, or negative scaling. Since RDNA 2, it is no longer possible to dial in a specific frequency; rather, the minimum and maximum target frequency range is adjusted, which still is no guarantee, hence "target." The problem is that the clocks will not change if the card is limited by power. As such, you have to dial up the power limit to gain the necessary headroom for the overclocked frequencies to activate.

Memory overclocking is complicated by the fact that these chips have error correction. So if they are unstable because the overclock is too high, there won't be crashes or rendering errors. Rather, the memory will keep trying to replay the transaction, which results in correct output eventually, but at much lower FPS. You'll have to experiment with the memory overclock until you find the sweetspot where you've still gained performance.

Maximum Overclock Comparison
	Avg. GPU Clock	Max. Memory Clock	Performance
ASUS RX 6600 XT STRIX OC	2797 MHz	2275 MHz	137.2 FPS
MSI RX 6600 XT Gaming X	2647 MHz	2225 MHz	131.3 FPS
Sapphire RX 6600 XT Pulse	2713 MHz	2300 MHz	134.4 FPS
XFX RX 6600 XT Merc 308	2713 MHz	2175 MHz	132.2 FPS