PowerColor 7900 XTX HellHound Review

Clock Speeds

Now the other area that’s worth looking at with any custom card is how things perform in terms of cooling and power delivery.

What we saw here was that the GPU temperature sat consistently at 66 degrees which is around the same temperature that we saw on the reference card from AMD. The memory junction also came in around the same at 90 degrees on the HellHound and the Hot spot remained under control at around 86 degrees which admittedly is 2 degrees warmer than the reference card. The GPU clock saw levels around 2430MHz for the most part with 100% GPU utilization, and during this, the total board power did rise to around 360 Watts with the fans remaining a very quiet 1200RPM though that was overshadowed by some pretty severe coil whine in places.

Now in terms of overclocking. RDNA 3 is a fickle mistress. It’s not as simple as moving sliders across and away you go, but instead, requires a little more precision, and after working with both MSI Afterburner and AMD’s own inbuilt controls, the real trick seems to lay within raising the power limit by 15%, undervolting by around 125mV and then increasing the memory slightly while retaining full stability. What this allows is for the GPU to boost at the standard levels for a little longer and give higher boost levels for a longer sustained period of time.

What this resulted in was an increased GPU temperature which hovered around 69 degrees, and a slightly higher memory junction temperature too, at 92 degrees, along with the hot spot temperature which also increased to 92 degrees. However, this did result in a much higher boost clock, now sitting just below 2700MHz. The power of the card did increase quite dramatically to 415 Watts, and while the fan speed did increase, at less than 1500 RPM, it was still incredibly quiet.

Through overclocking, it did iron out a few smooth spots which saw around a 15% improvement in the FPS, but on the upper end of the performance, there was only around 5% between stock and overclock performance.