AMD Radeon RX Vega 64 8GB review (Page 32)

AMD Radeon RX Vega 64 8GB review

Graphics cards 1048 Page 32 of 34 Published 2017-08-14 15:00 by Hilbert Hagedoorn

Overclocking The Graphics Card

Traditional overclocking - As most of you know, with most video cards you can apply a simple series of tricks to boost the overall performance a little. Typically you can tweak on core clock frequencies and voltages. By increasing the frequency of the videocard's memory and GPU, we can make the videocard increase its calculation clock cycles per second.


Original	This sample	Overclocked
Base Clock: 1247 MHz	Base Clock: 1247 MHz	Base Clock: 1700 MHz
Boost Clock: 1546 MHz	Boost Clock: 1546 MHz	Max Boost Clock: 1700MHz
Memory Clock: 945 MHz	Memory Clock: 945 MHz	Memory Clock: 1060 MHz

You can use any tweaking utility of your preference of course. You can use the internal driver Wattman. Our applied tweak:

Core: 1700 MHz
Mem: 1060 MHz data-rate
Power: +50%
Voltage GPU: 1150 mV
Volatge mem: 1200 mV
Fan: Default

The overclocked results closing in at 1.7 GHz. As the metrics show, that is a stable tweak.

However, during our OC session, no-matter what we tried - under load the GPU would automatically down-clock massively, likely due to safety protections or hitting certain load limiters. We're a bit in the dark as to how well the cards in the end will overclock. The performance, despite the tweak, did not change very much due to some random downclocks.

If you look at the upper graph you can see the speed bins ( status 0 to 7); we think the card, once it hits the thermal limiter, drops back to, say, status mode 5 with, say, 1200 or 1400 MHz tied to it. So the first segment of our test would run nicely at 1.7 GHz, but the second it hits a limiter it goes down fast to 1500 and 1600 MHz ranges. This lowers the overclocking results significantly:

In the above chart you can see the relative performance difference in between a reference card and then after we added the applied tweak, our overclocked results are plotted in percentages.

As you can see, due to the downclocking the results remain icky. In the end that high-clock tweak brought us just 5% extra performance. I'll await some new driver updates before I make any solid conclusions here, but this is not looking good. It seems that Vega downclocks big-time once it hits certain limiters. And on long run gaming that is bad news (when tweaked).

We halted testing overclocking until AMD can deliver a final driver where it works properly.

There are sliders in the Wattman control panel that allow users to change the clock speeds for the GPU's highest power states. You'll see them there if you pick the “custom” profile.

Unfortunately, there was an issue in the press driver where adjustments made to these sliders are not applied. An updated beta driver however ONLY allowed us to use this driver for playing with Wattman. The standard performance and other tests should still be performed with the previously uploaded driver. Not even AMDhad time to test this functionality with all other aspects of the driver and needs further testing before prime time.

Overclocking The Graphics Card

Overclocking The Graphics Card

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