Radeon RADV Driver Enables Displayable DCC For Some Performance Benefit

[agd5f]

I think this is closer to Intels RBC than framebuffer compression. AMD also has framebuffer compression but AFAIU that is purely the display side (e.g. the display HW compresses it on scanout to reduce bandwidth for the exact same image on next scanout which helps with relatively static desktops)

DCC actually replaces the legacy framebuffer compression in the display controller. It serves both purposes on asics which support it.

[brent]

Wow, DCC wasn't already implemented in RADV? This is actually amazing. DCC is no joke, it can bring a sizeable performance improvement in demanding games. I thought that with RADV performing that well it was already implemented. Can't wait for this now

No, this is just a special case. In general, DCC has been supported for quite a while.

[TemplarGR]

Wow, DCC wasn't already implemented in RADV? This is actually amazing. DCC is no joke, it can bring a sizeable performance improvement in demanding games. I thought that with RADV performing that well it was already implemented. Can't wait for this now

[BNieuwenhuizen]

Yeah. Displayable DCC seems to be more or less what Intel traditionally calls "framebuffer compression", although it looks like DCC is somewhat more advanced (IIRC Intel's framebuffer compression is just a basic RLE scheme, at least it used to be).

This kind of compression saves bandwidth and that can improve performance, but the real win (on mobile devices) is reduced power consumption.

I think this is closer to Intels RBC than framebuffer compression. AMD also has framebuffer compression but AFAIU that is purely the display side (e.g. the display HW compresses it on scanout to reduce bandwidth for the exact same image on next scanout which helps with relatively static desktops)

[brent]

Yeah. Displayable DCC seems to be more or less what Intel traditionally calls "framebuffer compression", although it looks like DCC is somewhat more advanced (IIRC Intel's framebuffer compression is just a basic RLE scheme, at least it used to be).

This kind of compression saves bandwidth and that can improve performance, but the real win (on mobile devices) is reduced power consumption.

[Peter Fodrek]

Does this come with less good visual quality ?

storing pixel differences within a block as a delta relative to one pixel at full precision per block

is there any difference between


200.000.000 (in memory, yet ) + 342 (send via bus)

and

200.000.342 in memory just now?

Nope.

But on the bus there is only 342 when using DCC or full 200.000.342 when no DCC is used. in decimal there is 3x less bandwith (and or power consumption on the bus ) needed for same resolution or 3 times higher resolution on same bandwith.

[brent]

Does this come with less good visual quality ?

No. It's lossless.

[skeevy420]

Delta Color Compression; also known as a Mississippi prison.

[Danny3]

Does this come with less good visual quality ?

[phoronix]

Phoronix: Radeon RADV Driver Enables Displayable DCC For Some Performance Benefit

The open-source Mesa Radeon Vulkan driver "RADV" has now enabled displayable DCC (Delta Color Compression) support that should yield some performance benefit while there still is more work to be completed...

http://www.phoronix.com/scan.php?pag...isplayable-DCC