Well ... as this thread has attracted all kind of 120 Hz experts out of woodwork I do have actually a question which hopefully someone in this thread can shine some light on.
About overclokability of ipad 4 screen. From the manual following block diagram can be found:
On the block diagram you can note TCon with words mangolia and parade next to it. That makes me think that the ipad4 screen uses DP628 TCon from company called Parade (link: http://www.paradetech.com/products/displayport-lcd-timing-controller-products/dp628-4-lane-dp-tcon/
Two things to note in here. (1) It's displayport 1.1a (max bandwidth 10.8 Gb/s) (2) It supports 120 Hz panels at "reduced resolution" (would 2048x1536 be a reduced resolution?)
A single frame with 8 bit colors at ipad 4 resolution is 2040x1536x3x8 = 73.73 Mb (no error corrections) - that means that theoretically, without any error correction a DP 1.1a at full bandwidth would be able to drive 2048x1536 screen with 8 bit colors at ~135 Hz. I am not familiar with DP standards but I think there was also some error correction - assuming about 10% bandwidth reserved for error correction would still leave us at ~120 Hz max. So cable bandwidth wise it should be theoretically possible to drive this screen at 120 Hz. If its possible in reality ... well .. that remains to be seen. I will certainly try once I get mine working.
This is from post #139 in this thread: http://www.overclock.net/t/1389756/custom-screen-31-3600x1600-cost-250/0_50
- so anyone familiar with the TCon units used in todays displays in more intimate terms? Would love to hear any comments.
In a nutshell the idea is to build myself a 3x1 portrait setup from ipad 4 screens. Spec sheet of the screen lists supported display modes as
120 Hz (60HZ Input): Embedded MEMC Circuit
120Hz + 120 Hz : 120 Hz Panel + 120 Hz Backlight
240 Hz (60HZ InputI): Embedded MEMC Circuit
So I'm kind of hopeful that I might perhaps be able to drive these at 120 Hz. But I'm not familiar with the internals of displays so just sitting there how to proceed with that once I get the parts. will just doing a manual EDID override do the trick if I slap the screen with 120 Hz signal or would it be more elaborate and involve opening up the LCD panel and doing "stuff" to it. As far as I understand the screen runs at 120 Hz (first two modes) or at 240 Hz (third mode) out of the box, its just that if you give it 60 Hz signal it uses interpolation.