Temperatures and GPU Frequencies
Gaming Temperatures and Clock Frequencies
We start with our gaming loop, comparing Sapphire's silent and boost modes. In the two graphs below, temperatures and clock rates are recorded on an open bench table and inside of a closed PC case. The fact that there's really no difference in temperature shows the cooler keeping up with what we're asking from it.
The GPU frequency in silent mode is up to 1411 MHz, whereas boost mode achieves 1450 MHz. Neither setting is consistent throughout our test period, but they get close.
The Nitro+ Radeon RX 580 Limited Edition's 1450 MHz boost mode does represent a fairly rigid overclocking ceiling for this GPU, though. We have to assume we're already working with a hand-selected processor, and manually overclocking it beyond the boost clock rate is practically impossible. Pushing any higher simply results in the frequency dropping more often.
The most we were able to get out of Sapphire's golden sample was 1475 MHz. That's not much of an increase, and the subsequent pull-backs brought the average down to 1450 MHz. In short, manual overclocking is almost completely pointless. And we don't have anything nicer to say about our efforts with the memory.
Still, we observed temperatures between 74 to 76°C on our open bench table and closed case, and those are solid figures.
Stress Test Temperatures and Clock Frequencies
An even more taxing stress test challenges Sapphire's cooling solution more than any real-world workload. And the result is a drop in clock rate that erodes all of the boost mode's advantage. It doesn’t matter which BIOS setting you pick or if you run the card on an open bench; the result is the same.
Using Sapphire's overclocked settings, the cooler reaches its limit. Its fans spin noticeably faster and yet the temperature still ends up a tad higher at 76°C. We even see 78°C briefly.
GPU temperatures only tell part of the story, though. We also need to take measurements across the rest of the board.
Because Sapphire's backplate plays an active role in cooling, we didn't remove it from the Nitro+ Radeon RX 580 Limited Edition. Luckily for us, Sapphire provides gaps in the metal right where we need to point our infrared equipment, saving us from drilling holes.
Gaming Temperatures in Silent Mode and Boost Mode
Temperatures corresponding to both of the board's operating modes are shown below. You'll find two infrared thermal pictures each: the left one reflects performance on an open bench table and the right one is in a closed PC case.
The GPU package's temperature is much higher than what the integrated diode would have us believe. That heat comes from the PCB and its metal layers.
In boost mode, the GPU and its package get at least as hot as before, while all of the other components remain a lot cooler. You see, they benefit from the faster-spinning fan and its increased airflow (even if the consequence is more noise).
Stress Test Temperatures in Silent Mode and Boost Mode
We push the Nitro+ Radeon RX 580 Limited Edition's cooler to its limit once again with a stress test. Sapphire’s marketing material touts the thermal solution's ability to cope with up to 300W, and our loop provides a respectable 240W. This is just about as far as the GPU can go, yielding an effective worst-case scenario.
In boost mode, the load is consistently more debilitating, yet the fans don't speed up as much as they did in silent mode. As a result, we measure higher temperatures in several places across the board. Still, our readings are perfectly acceptable.
Sapphire's cooler does its job well and may even offer a bit of thermal headroom. Kudos to the company for arming this generation's Nitro+ card with a clear step up from its predecessor.
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