AMD Radeon R9 290X Video Card Review

AMD is launching the Radeon R9 290X today. The R9 290X represents AMD's fastest single-GPU video card ever produced. It is priced to be less expensive than the GeForce GTX 780, but packs a punch on the level of GTX TITAN. We look at performance, the two BIOS mode options, and even some 4K gaming.


PowerTune and "Quiet" and "Uber" Mode

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The way PowerTune works is completely new and different on the Radeon R9 290X and 290. AMD has several goals with the new PowerTune, leave no Watt unused, produce no unnecessary noise, allow complete customization, and maximize the potential.

The clock speed is now completely dynamic on the R9 290X and R9 290. AMD tells us that the clock speed can change dynamically every 30ms. That means that every 1 second, the clock speed can change 33 times. In 1 minute that means the clock speed can change 1,980 times.

New hardware on the video card allows this dynamic clock speed. There is a 2nd generation serial VID interface, which is a new controller interface designed by AMD. The controller allows voltage switching times on the order of 10آµs (microseconds). The controller allows a 6.25mV voltage step granularity and 255 voltage steps between 0.00V to 1.55V. There is a dedicated SVI2 Telemetry line providing voltage and current feedback at 40KHz sampling and 20Mbps of telemetry bandwidth. The controller allows multiple voltage domains as well.

Power and Temperature affect Real-Time Clock Speed

This is important to understand because now power, temperature, and application demands will determine the frequency the GPU is running at, up to the maximum frequency specified. What will happen now is that there will be a max frequency set, in the case of the R9 290X this is 1000MHz stock frequency. The GPU is able to dynamically clock itself up to 1GHz if all the conditions are right. However, it will not go over 1000MHz; there is no "Boost" like on the GeForce GTX 600/700 series.

If the conditions are not right to maintain this 1GHz clock speed then it will downclock from 1GHz until it achieves harmony with the power demand and temperature. Unlike prior generations, the video card will now try to keep your GPU at the set frequency in the temperature and power envelope you set. The best way to fully understand this is to see it in action, but we will try our best to explain. We will also dive into this more when we overclock the video card in a follow-up article.

New OverDrive in Catalyst Control Center

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In the new Catalyst Control Center you will find that the default settings AMD has set for the R9 290X is a running GPU temperature of 95c and a maximum fan cap of 40%. Say what now? Yes, what you have to get familiar with now are "caps" that the GPU is allowed to run up to. If you raise these caps, performance can go up, but so will power and noise. If you set low caps, the performance will go down, but so will power, and noise. The new OverDrive allows you to dial in the power limit and temperature you are comfortable with, complete customization.

Firstly let's start with temperature. AMD has set the default temperature of these GPUs to run at a max of 95c. That means that the GPUs are going to run at 95c. This will be a shock to you at first, as you are not used to your video card running so hot, but it is OK. AMD states that the thermal threshold for these GPUs is well above 95c. AMD is confident in the set temperature of 95c to deliver a stable experience. There is no technical reason to lower the temperature, but you have the option to if you want.

Second, and this affects the temperature of course, is the fan speed. AMD has set the default fan speed to a cap of 40%. What this means is that the fan speed cannot and will not ever exceed 40% rotational speed at stock settings. This creates a "quiet" operating condition. AMD has chosen quiet, over pure performance, for its default configuration.

What you have going on is that the video card will always try to give you the highest frequency it can, up to 95c temperature with the fan spinning up to 40%. This doesn't always mean it will be at 1000MHz though. In power demanding apps and games, the clock speed will often clock itself below that frequency because it can't maintain 1000MHz at 95c with 40% fan.

We found that power hungry games like Crysis 3, Far Cry 3, and most likely BF4 have a reduced in-game frequency. We experienced the frequency dropping as low as 200MHz while playing Crysis 3. A frequency drop of 200MHz can certainly impact your performance.

Dual-BIOS Modes - "Quiet" and "Uber" Mode

AMD has given you a choice, do you want "Quiet" or do you want "Performance." AMD is utilizing the BIOS switch atop the video card. With a flick of the switch and a reboot, you activate the "Uber Mode" BIOS. All retail cards will ship in the "Quiet Mode" position. In this Uber Mode the fan is set to run up to a cap of 55% now instead of 40%.

This means while you game the fan can run faster and louder. This also means it helps reduce the temperature more, and in turn allows higher sustainable frequencies on the GPU at 95c. In our testing, this did result in better performance in several games. Some of the performance gains were small, others were larger, depends on the game.

In order to get the frequency of the GPU to maintain a closer to 1000MHz range, temperature is everything, and the fan is the easiest way to control that. Though AMD offers this "Uber Mode" we still feel 55% isn't high enough. You can of course manually set the fan to a higher cap, and we did some tests with the fan at a cap of 100%. This doesn't mean the fan will always run at 100%, the fan is still dynamic and automatically adjusted, it just means the fan can go up to 100% if the controller pushes it there.

With the fan at 100%, or basically uncapped, we did notice games, and even benchmarks, did score higher still compared to the "Uber Mode." Therefore, the R9 290X is being held back in performance all because the fan is capped at 40% by default in "Quiet Mode" and 55% in "Uber Mode."

PowerTune Summary

"Quiet Mode" آ– BIOS position one. Switch is in position closest to where you plug in your displays. Fan is at 40% cap.

"Uber Mode" آ– BIOS position two. Switch is in position furthest away to where you plug in your displays. Fan is at 55% cap.

There is more performance, but in order to tap that performance you have to unlock the fan cap on the reference card design with reference cooling.

For the purpose of this evaluation, all the gameplay is tested in the default position of "Quiet Mode" because this is the position that the BIOS will be in for all retail shipping video cards. We do have comparisons to the "Uber Mode" and to 100% allowable fan speed as well later on in this evaluation.

Please keep this in mind, add-in-board partner custom video cards could end up very different. AIBs are allowed to change the BIOS, and of course create custom cooling. The custom cooling alone could change the outcome. Perhaps with really good custom cooling the full potential will be exploited anyway. AIBs will also customize the fan speeds, so the rotational speed on the products could be very different, with different caps, or no caps at all.

We are simply evaluating the reference design and reference cooler setup in this evaluation. With reference cards, with reference cooling, keep all of this in mind, it is very important and will affect the performance of your card. Custom cards? We will have to wait and see what happens when we start to review them. Our suggestion, go with a custom card with custom cooling so you get the best performance you can. If you are spending this much money on a video card, you don't want it held back because of a fan speed cap.