ASRock's High-End Vision 3D 252B HTPC Review 8

REFRESH RATE HANDLING

One of the issues with the ASRock CoreHT 252B was the fact that the integrated Intel HD Graphics 3000 was unable to refresh the display at 23.976 Hz even when configured manually. AMD GPUs have had a history of being close to the desired refresh rates out of the box, while NVIDIA GPUs end up needing some tweaking. This is further compounded by the fact that different setups behave differently even with the same card. How does the GT 540M  in the Vision 3D 252B fare?

As we have recounted in earlier HTPC reviews, a GPU should ideally be capable of the following refresh rates at the minimum:

1. 23.976 Hz
2. 24 Hz
3. 25 Hz
4. 29.97 Hz
5. 30 Hz
6. 50 Hz
7. 59.94 Hz
8. 60 Hz

Some users demand integral multiples of 23.976 / 24 Hz because they result in a smoother desktop experience, while also making sure that the source and display refresh rates are still matched without repeated or dropped frames. The gallery below shows the refresh rate handling for 24, 25 (x2 = 50 Hz), 29.97 (x2 = 59.94 Hz), 30 (x2 = 60 Hz), 50, 59.94 and 60 Hz settings.

The native 23 Hz setting, unfortunately, resulted in a 23.971 Hz refresh rate.

However, with some custom timing setup, we were able to achieve 23.97634 Hz.

The custom timing feature is usable, but not without its quirks. Adding a custom resolution is straightforward. Setting the vertical parameters to values similar to the ones in the screenshot above achieves desired results, but the 23 Hz resolution gets saved as 24 Hz. The pictures in the gallery below bring out the issue. The first picture shows that the 23 Hz setting gets saved as 24 Hz in the NVIDIA control panel. The second picture shows that the 24 Hz setting is no longer available in the set of native refresh rates. The third picture shows that all the available EDID resolutions are displayed in the monitor properties. The fourth screenshot shows that setting the 23 Hz option in the monitor properties puts the control panel in 24 Hz custom mode (with the screen refreshing at 23.97637 Hz). The fifth screenshot shows the effect of setting the 24 Hz option in the monitor properties. Note that the control panel still shows the custom 24 Hz setting. In the sixth screenshot, we selected the 23 Hz setting of the NVIDIA control panel (under native resolution - the one that we actually intended to replace in the first place) only to get the display refreshing at 23.971 Hz. The final picture shows the NVIDIA control panel set to custom 24 Hz resulting in a display refresh rate closer to the intended 23.976 Hz. We hope NVIDIA fixes this annoying issue in one of the upcoming driver releases.