Originally Posted by Dave in Green
, from a quick look at the specs it seems that those two $20,000 professional laser projectors may have the same guts from the same OEM. If so I'd consider it to be more of a single case of 3D implementation. If 3D implementation was baked into TI's 0.66" XPR chip it seems reasonable to assume that at least one consumer projector would have it. So it's possible this 3D implementation is accomplished with add-on circuitry and is not native to the TI chip. With the 0.47" XPR chip having 3D baked in it's less likely that a projector company would spend more to add 3D to the 0.66" XPR chip in a consumer model where there is more added pricing sensitivity than on expensive specialty professional models like these. But without more solid data we're just guessing like we were yesterday on which chip was really in the UHD50.
The thing I don't really understand about the 0.66 XPR chip doing 3D is this:
DLPs do 3D using either DLP Link at 144hz (triple flash 24p = 72hz per eye times two eyes = 144hz), or using IR emmitters synced to LCD shutter glasses at 120hz.
To achieve 144hz at 2716 x 1528 internally in the projector, with XPR disabled for 3D, you have to take a 1080p 3D input at either 24p or 60p (in SBS mode or O/U mode or maybe even Frame packing FHD per eye), upscale it to 1528p, then show it at 144hz.
Problem is, these projectors run at 120hz internally for 4K operation using XPR shifting, so how can they do 144hz? Is it extra lee-way?
It's for this reason I suspect they only support 1080p 60hz input and project 3D at 120hz, not 144hz.
2716 x 1528 x 60 x 2 (eyes), already consumes all the 600 Mhz controller bandwidth internally, which is the same max bandwidth as 18 gbps HDMI 2.0 can provide at 4K60 using XPR shifting in 2D mode. So 1080p60 should be the maximum input refresh rate and resolution, and the 3D operation should run at 60hz per eye, constantly. Anything lower would result in flicker.
DLP Link I believe can run at 120hz, not just 144hz. If they are doing triple flash 3D for 24p content then their internal electronics must be pushing beyond the max specs they are running at for 4K60 2D mode.
I believe they don't offer frame packing 24p mode because the only way to display that in 3D smoothly, is 24p per eye, so 48hz, times two (double flash) at 96hz. Does DLP Link work at 96hz? I thought 120hz was the lowest you can do without flickering. Doesn't JVC do 3D at 96hz and result in poor 3D?
If 2X XPR projectors do triple flash at 144hz they must be overclocking some system components past the bandwidth required for 4K60.
The 4X XPR shifting 0.47 1080p chips can just disable XPR shifting and show 1080p as is, without scaling, so the DMD controllers don't need to do any electronic upscaling to 1528p first, in their internal frame buffers, meaning they can easily do 1080p 120hz, 144hz, or even 240hz (120hz per eye FHD) if they wanted to.