Testing AMD’s FreeSync

It’s works, it’s free, and its available

AMD stopped by Mt. Tiburon Testing Labs last week and dropped off a slick, 21:9, 2560 × 1080, LG, 34-inch ultra-wide FreeSync monitor. LG introduced the monitor at CES this year. Unlike the Gsync monitors, which have only a DisplayPort connector, the LG 34UM67 has DP, HDMI, and DVI, but no USB inputs. However, the IPS screen covers 99% of the sRGB color spectrum. SUPER-WIDE SCREEN is difficult to photograph.

The monitor will run from 48 to 75 frames per second (FPS) and has a fast 9.5-ms response time, and LG claims their “Dynamic Action Sync” technology would shave a few more milliseconds off that time, although they don’t explain how.
Similar to the 34-inch curved monitor we reviewed recently, you control the monitor’s software options (picture modes, brightness, etc.) via a small joystick button at the bottom of the bezel.

AMD AIBs that support FreeSync.

AMD says they have the support of the majority of monitor vendors. Most of the AMD AIBs can support FreeSync, which includes the 260, 265, 285, 290/290X, and 295X2. The older 270 and 280 series AIBs can’t do it because they use the previous-gen display controller. WINDMILL DEMO of smooth FreeSync operation.

AMD has a nifty utility program to demonstrate FreeSync. There is a windmill, which nicely shows stutter and jitters without FreeSync and perfect rotation with FreeSync on. However, my camera wasn’t fast enough to get a perfect shot (next page).

FreeSync will work with and without Vsync on. With Vsync on, the monitor will run at its maximum refresh rate, but may stutter. Turning on FreeSync not only eliminates the stuttering in this case. Conversely, with Vsync off, the render rates of the GPU are not limited by VSync, but you may see tearing. Turning on FreeSync in this case will eliminate the tearing, and if the application can drive frame rates over the max refresh rate of the monitor, FreeSync can accommodate by allowing VSync-off behavior outside of the range.

AMD’S “RED” vertical bar is perfect with Vsync and FreeSync on.The monitor looks great; a super-wide screen is really an enjoyable experience, and the LG adds to that with its dynamic contrast ratio of 5,000,000:1, a brightness of 300 cd/m², and 178°/178° viewing angles. And at an SRP of $649 in the U.S., this is an easy buy. LG however, isn’t alone a there are some formable competitors with offerings in this new gaming monitor category.

New gaming monitors with wide-ranging resolutions and refresh rates give gamers choices at every price point.

What do we think?

The down side is not all games can use this new resolution range (2560 × 1080). For example, Unity’s Valley benchmark doesn’t support this resolution. However, many games will allow edit-ing of the .ini file, and you can fix the resolution there. Also, there will be a number of new FreeSync monitors coming in a variety of resolutions.

Nvidia has to be acknowledged in this as they brought the issue to light over a year ago with the introduction of their G-Sync technology. G-Sync requires the monitor builder to add an Nvidia scaler and interface board, which raises the price of the monitor a bit.

FreeSync also has some associated costs for the monitor builder:

  • Vendor chooses the scaler chip that is capable of DisplayPort Adaptive-Sync
  • Vendor chooses the LCD panel that is capable of supporting a range of refresh rates
  • Vendor designs and builds monitors
  • Vendor runs test cases supplied by AMD to ensure monitor meets FreeSync requirements
  • Vendor sends the report and samples to AMD for verification

Nvidia says they offer a wider refresh range with their solution and that AMD only offers “no-tearing” game play across a limited window. For the LG IPS, that is only a 27 fps window. If the game play drops below 48 fps, it starts tearing, according to Nvidia— that won’t happen with G-Sync, says the company. Nvidia says they are showing demos that vary between about 30 and 60 fps. However, to be fair, AMD will be showing an Acer and BenQ (see chart, preceding page) high-res monitor with 40 to 144 Hz—a 104 fps window. 

With the LG IPS, there is only a 27 fps window. If the game frame rate goes out of this range, AMD offers the choice to end users to define the behavior. They can choose VSync ON (and have some stutter, but no tearing), or they can choose VSync OFF (and have some tearing, but no stutter). The range of any give monitor is usually defined by the capabilities of the LCD panel. AMD has stated that they can drive a range of 9 to 240 fps, but in reality, there isn’t an LCD panel with this capability on the market yet.

The bottom, as they say, is regardless of which solution you choose, this is a win-win for the gamer.