ASUS STRIX R9 380 DirectCU II OC Video Card Review

Today we are taking a look at the high end of ASUS' offerings featuring the Radeon R9 380 GPU in the form of the ASUS STRIX R9 380 DirectCU II OC 4GB. We will pit it against the MSI GeForce GTX 960 GAMING 4G to see which card can be crowned king of the hill in the low $200 price range.

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Card Issues

Over the course of several overclocking sessions, as well as some of our initial gaming experience with the card, we noticed that at seemingly random times during a gaming session, we would get inconsistent performance out of the card that lead to performance that was far below our expectations at a given resolution and graphics settings. This poor experience was noticeable at stock speeds but not always present, in a way that was not reproducible but usually ironed itself out during the course of gaming. However, it was present during virtually every overclocked gaming session until we determined the root cause of the issue.

We noticed that the GPU core clock would repeatedly throttle down to 300MHz every few seconds while gaming even though the GPU was running at a cool 74 degrees Celsius most of the time, fans were spinning at about 39-40% levels and it was not throttling until that point. When taking the vitals of the card during this performance, we saw that the PWM temperatures had climbed to 129-130 degrees Celsius, a temperature that approximates its maximum design temperature. This appeared to be the root cause of the throttling, as when we increased the fan speed, the PWM temperatures dropped to about 115 degrees Celsius with the fans at 60% and that resulted in the gaming experience that we were expecting. There were some sessions where this particular issue did not appear, and those were when the fans had elected to run faster during a particular gaming session which kept the PWMs sufficiently cool.

Ultimately, the ASUS STRIX R9 380 DirectCU II OC’s factory fan profile does not appear to consider the PWM temperatures in setting the fan speed, which is unfortunate as the DirectCU II cooling solution does not touch the PWMs, causing them to fully rely upon the airflow coming from the fans to maintain an appropriate temperature.

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ASUS' Response and Resolution

We reached out to our contacts at ASUS and shared our observations. We were initially going to get a replacement card to see if our observations were the result of a faulty card, but ultimately, ASUS decided to make a change to the VBIOS to see if it could be resolved without replacing the hardware. A couple weeks later, we received the new VBIOS in hand, we flashed the card and fired up some games.

Our initial observations were the only thing that appeared to change was the fan profile when running under a full overclocked load. Instead of the fans running at 39%, we observed them running at 44%, which presented slightly better temperature numbers across the board. In our gaming, we did not notice the issue at stock clocks during any of the play time. With respect to the card running at its maximum overclocked speeds, the PWMs would generally settle in around 120-127 degrees Celsius and perform without any of the hiccups that we initially found. When we pushed the card as hard as we could by going slightly over our maximum stable overclock, we were able to get the PWMs to hit 129-130 degrees Celsius just before a spectacular crash would occur. We noted that overall performance did not change between the original and the updated VBIOS. ASUS confirmed that the only change to the VBIOS was the default fan profile and it continues to not consider PWM temperatures as part of the fan profile.

That being said, the VBIOS update appears to be the appropriate fix for our environment, however, we would prefer to see the fan profile being a bit more aggressive, as there are a few variables that our test setup does not take into consideration. As you know, we perform our tests on open air benches at room temperature. The impact of a higher ambient temperature inside of a case could be troublesome to the issue at hand, and it should certainly be a consideration for our readers. Additionally, given that the temperatures were running near the limits, there's no wiggle room before a poor experience would be encountered. Ultimately, we were far more comfortable running the fans at 59% when overclocked, which produced PWM temperatures around 115 degrees Celsius.

The ASUS reps stated that the adjusted VBIOS will be made available on the ASUS STRIX R9 380 DirectCU II OC 4GB support website and will be used on all production cards going forward, however, as of the time of the publication of this evaluation, it has yet to be posted. One other thing to keep in mind is that GPUz reported the same VBIOS version for both our initial VBIOS and the updated VBIOS, so it will be difficult to tell which one you have installed on your card without looking at what the fan profile does under a full load.