Radeon 9000 pro texture loopback!?!

[Prometheus]

From what I read at Anands and Techreports review radeon 9000 pro achieves the six textures per pass via loopback.Anand says that radeon 9000 pro will have problems in performance in quadtexture and up games (as shown in unreal tournament 2003 benchmark)because the loopback is not yet supported.I think I read something the same about the vertex shader unit.Can someone please explain how can and if there will be support for the loopback in games like UT 2003,Doom3.
I'm thinking of getting one because it's real cheap and get an r350 or nv35 near the Doom3 arival.
Dave when are you planing on a hercules radeon 9000 pro 128mb review?
Sorry If I've made any tech mistakes but I'm no expert

 

[Dave Baumann]

'Loopback' doesn't need to be supported by an application as it acts just the same as multitexturing as far as the application is concerned. For instance its long since been said that Q3 was fixed at 2 texture per pass - for a card that has two texture units it would apply these in one clock; for a card like the 9000 it will just apply these over two clocks.

Applications such as Serious Sam have a litte more felxible appraoch by allowing you to configure up to 4 texture in a pass - in 9000's case it will just apply these over 4 cycles.

As textureing felxability increases the number of physical texture units per pipe will become less of a concern as opposed to the number of supported texture per pass - application will look at this and configure themselves accordingly. 9000 support 6 texture per pass, and as far as the application is concerned this is as good as having 6 texture units per pipe (although it just mean its slower becuase it has to do it over muliple cycles).

I'll be reviewing the ATi 9000 PRO first as thats what I've got. Testing has already started.