TX files are tiled atlas/mipmapped/streaming texture files. They significantly reduce texture memory footprint. Vray also has a tiled exr system.
Arnold in a film production, for example, might need to render 100s of gigs of textures files. Impossbile without streaming/mipped texture atlases.
Current blender task
is this something you set in blender or when saving the image?
When saving the image, even if you set the image node as NonColor in Blender it will still read the 3 channels, or at least that what I’ve seen
Haha, from 5 years ago and based on one post there it seems it would take around 18 months to do once it’s been decided to actually do it.
Basically it’s not going to happen in the next 5-10 years and everyone should plan accordingly.
Or maybe Nvidia will release a ‘cheap’ consumer GPU with bucket loads of VRAM… 
O’ look, is that a flying pig 
Side note, we need an emoji of a pig with wings…
Of course. Color management has nothing to do with channels.
Only the stuff that makes my life easier… 
I do not think it means what you think it means.
Plus, from that dev thread it sounds like a process that could take years.
Cycles also spent much of that time not having any full or even part time developers, and Brecht leaving for a couple of years to work at Solid Angle did not help either. The Blender development fund also brought a fairly small amount back then compared to today so they could not afford a developer just for Cycles anyway.
It was not until Cycles X that full-time work on the engine resumed and not until the last couple of years that the Cycles module had multiple people on it (so as to keep work ongoing if the project lead was on holidays or in this case a sabbatical).
The result is that we now have a number of longtime todo items and issues being tackled, and hopefully this means texture processing will receive renewed attention.
this pitch is a ux nightmare: but i could see scenarios where fast converging gi renders is a top priority and a ‘principled-shader-only’ rendering mode would still be incredibly useful.
I don’t know what else to use. 
Damn.
Good that I have invested time and effort in multiple contingency plans.
Tiny bit off topic, but for those interested in ReSTIR, you can try the AMD ProRender add on. I didn’t try it my self so I have no clue how well it works, but it is using ReSTIR.
OMFG! Time really flies. Funny and sad at the same time. Thanks for the throwback 
Was Lightcache removed or changed in 4.3 GPU rendering?
I had some issues with it and in 4.3 it’s gone.
This guy:
https://x.com/themikepan/status/1801389268621001033
Using everything I learned below, we can get 1.5GB of GPU memory saving on the Gooseberry benchmark:
Packed Textures: 6024MB
Unpacked Textures: 5589MB
Unpacked Textures with greyscale maps converted to 8bit: 4592MB
