AMD FreeSync will be adopted by VESA

#4796803 Posted on: 04/08/2014 09:25 AM

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So basically everyone that already owns a monitor/HDTV and has it connected to their discrete gpu is out of luck for enjoying either FreeSync or G-Sync. Correct?


Yes.

http://www.pcper.com/reviews/Graphics-Cards/AMD-Variable-Refresh-FreeSync-Could-Be-Alternative-NVIDIA-G-Sync
"All that is needed for this to work, as AMD explained it, was an eDP connection between the discrete GPU and the display, a controller for the screen that understands the variable refresh rate methods of eDP 1.0 specifications and an updated AMD driver to properly send it the signals. The panel can communicate that it supports this variable refresh technology to the graphics card through the EDID as resolutions and timings are communicated today and then the graphics driver would know to send the varying vblank signals to adjust panel refresh times on the fly."

Laptop displays use an eDP connection, but existing desktop monitors do not. There's a scalar chip inside desktop monitors and it doesn't do dynamic v-sync which is why Freesync was demoed on a laptop. I'm fairly sure HDTVs are in the same boat with desktop monitors.


My question is: Do all modern laptops support ePD 1.0 and above and, if so, why doesn't nVidia include support for dynamic v-sync in their drivers? I mean, I can run BF4 on my laptop which has a GTX 675MX. With dynamic v-sync I could increase the detail settings and the game would still appear to run smooth.

#4796806 Posted on: 04/08/2014 09:29 AM

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why wouldn't you think its true? that it can only do 60hz in its current level...

#4796811 Posted on: 04/08/2014 09:39 AM

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Yes.

http://www.pcper.com/reviews/Graphics-Cards/AMD-Variable-Refresh-FreeSync-Could-Be-Alternative-NVIDIA-G-Sync
"All that is needed for this to work, as AMD explained it, was an eDP connection between the discrete GPU and the display, a controller for the screen that understands the variable refresh rate methods of eDP 1.0 specifications and an updated AMD driver to properly send it the signals. The panel can communicate that it supports this variable refresh technology to the graphics card through the EDID as resolutions and timings are communicated today and then the graphics driver would know to send the varying vblank signals to adjust panel refresh times on the fly."

Laptop displays use an eDP connection, but existing desktop monitors do not. There's a scalar chip inside desktop monitors and it doesn't do dynamic v-sync which is why Freesync was demoed on a laptop. I'm fairly sure HDTVs are in the same boat with desktop monitors.


Huum, well im not sure, but eDP connected monitor ( mainly laptop and mobile phone, tablet ) had allready the dynamic v-blank control, as it is used for reduce power usage of the monitor.

Now Vesa applied the "dynamic v-blank" to DP 1.2a as standard.. this is by software, you dont need a scalar chip .. Basically a new parameter is taking in account by the monitor software: it can ignore the timing of the v-sync ( i should say v-blank ), and let it controlled by the GPU driver.

The only thing is doing this vesa appliccations is add a new parameter in the actual 1.2a compliance: " MSA timing parameter Ignore" .. ( and not 1.3 as it was mentionned early in some article ) .

This is the assesment deposed by AMD to VESA compliance. and added in DP1.2a compliance.
Summary
Extend the “MSA TIMING PARAMETER IGNORE” option to DisplayPort to enable source based control of the frame rate similar to embedded DisplayPort.

Intellectual property rights
N/A

Benefits as a result of changes
This enables the ability for external DisplayPort to take advantage of the option to ignore MSA timing parameter and have the sink slave to source timing to realize per frame dynamic refresh rate.

Assessment of the impact
The proposed change enable per frame dynamic refresh rate for single stream devices that expose dynamic refresh rate capability in EDID for DisplayPort interface. The source will be able to enable this with an SST interface or MST hub with physical ports. Logical MST port support of the feature is not included as part of this SCR. A generic framework to enable such feature for logical port is required that can accommodate other feature where stream related configuration is programmed in DPCD.

Analysis of the device software implication
SST device which support “MSA TIMING PARAMETER IGNORE” option will be able to expose the capability in EDID and DPCD to let source enable dynamic refresh rate.
Source driver would have to be updated to parse EDID and enable “MSA TIMING PARAMETER IGNORE” feature when source want the sink to be refreshed based on its update rate.

Analysis of the compliance test and interop implications
Currently this feature is tested as part of eDP CTS. New test would have to be added as part of DP LL CTS and EDID CTS.

Based on an unnamed source, hardware.fr (google translate) appears to have seen the response to this document, specifically mentioning it in the line “Extend DP1.2a MSA Tmg settings Ignore Option AMD”. This indicates that the specific option AMD requested has been accepted, and will be extended into the DisplayPort 1.2a specification.

This should mean that any display supporting DP1.2a should support the dynamic refresh rate that is required for AMD to make use of what they called “Freesync” when they showed it off at CES. This is a developing story, and we’ll be updating it as new information comes in.

Now, does it need a firmware update ? or a driver monitor update, can it applied to exisiting monitor, HDTV ? .. i dont know.. we will need to wait more.

Something is sure, we can maybe expect any monitor in the future will got this function added, without any additional cost. Or monitor / TV manufacturers can improve and use this feature on their own for their panels.

#4796816 Posted on: 04/08/2014 09:48 AM

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I have 144hz running on my DP.

#4796821 Posted on: 04/08/2014 09:57 AM

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hmm...i couldnt get mine to go higher than 60hz @ 2560x1080