I emailed Intel Customer Support Service and they refer me to this forum because the agent say it will have the correct exposure to intel engineering department. (request # 8001214860)
The problem is Intel Graphics driver for HD 4600 (and presumably others too) have a broken custom resolution for Built in LCD. No matter what setting you put into it, it will always custom resolution exceeds the maximum bandwidth capacity.
I tested it on many different laptop with eDP (embedded displayport) like Alienware 17, Asus G751JM, Asus Q551LN, Lenovo Y50-70, Razer Blade 14, MSI GT60 Dominator Pro, and Gigabyte P34 and they all say custom resolution exceeds the maximum bandwidth capacity.
To establish the fact that bandwidth is not the problem, I tried creating a custom resolution at native res (1920x1080) at 59Hz (default is 60Hz) and it says custom resolution exceeds the maximum bandwidth capacity. To test it further I downscale the resolution to 1600x900 @ 59Hz and it still gives the error so I conclude the problem is with the driver itself.
I tried the oldest and newest driver from the OEM and the one on Intel website and they are all broken.
The problem is NOT ISOLATED on a laptop model or a manufacturer but the Intel Graphics driver itself.
In fact if you verify the problem by testing it on ANY laptop that has an Intel graphics and try to create a custom resolution that is 1Hz less than native (like 59Hz) and it will give you the same error.
So why does it matter? Almost every single gaming laptop that is being released are NVIDIA Optimus Enabled (Hybrid Graphics where Intel Graphics is handling the display) and it prevents people from changing the refresh rate of the display. As an example the LCD panel found on Asus G751JM-BHI7T25 uses LG LP156WF4 SPL1 which is the exact same panel found on Asus G751JY that comes at 75Hz by default, but we cannot change the refresh rate due to broken Intel Custom Resolution even though the LCD panel itself is more than capable to handle it.
Refresh rate is a huge feature as evident on monitors getting released (like BenQ XL2430T, Asus ROG Swift, Acer Predator, etc...) and if you ask any gamer that has tried a high refresh rate monitor they will tell you how much big of a difference it is and because of this issue, any gaming laptop that has Hybrid graphics (Intel Graphics enabled) is a HUGE deal breaker.
[Edit by Bryce@Intel]: Changed title to reflect investigation bug# and title.
Old title: Intel driver is completely broken (custom resolution)
Thank you, look forward to hearing from Bryce and seeing what we can do with this driver. I have already prepared a few systems and sent him the specifications so hopefully we hear back soon.
I'm getting some things cleared up with the developer first. I'll follow up quickly with them and circle back to you. Appreciate your patience and apologies for the delay.
Thanks for the update Bryce. Like the others have said I've been updating my email every hour or so over the last week. I've been waiting for years, I think I can handle waiting a little longer.
The delay was around some confusion about the code. My tech tested it several times and was unable to get it to work.
But great news, I've been able to verify it as working now by some other folks, not sure what my tech was doing wrong, so I'm pushing through the code changes and should have a target date soon for you. Stay tuned...
Excellent news Bryce! Looking forward to the driver and updates. Thank you for doing all you've done to get this driver from user wishes to an actual working product.
Will this fix be applied for all Intel HD graphics units? Or is this only for 4600?
I have the same issue with my Intel HD 530.
Thanks for further feedback.
this is relevant to that other thread . If the issue with CRU can be resolved many people wont be needing the EDID override anymore ( albeit it would still be nice to have )