R420 to have a 12X1 pixel pipeline configuration?

[Toaster]

Originally posted by schuey74
I can't be sure, but I would guess that their divided into quads as you stated. The reason being that many 9500 NPs could be unlocked to have a full eight pipelines, while many others could not at all. It would seem that you'd have some 5,6, & 7 pipeline 9500 NPs if you could pick and choose which pipelines to enable.

An educated guess would be that the R420 will be a 12x1 card and that ATI's next mid-range (think 9600) will be an 8x1 because of a disabled "quad". If possible, it would be great for ATI financially as all their high and mid-range cards would have the same core and perhaps even their low-end as well.....eventually.

You're right about the 9500, was just a thought though regarding the dynamic pipe allocations ;)

[Geforce4ti4200]

cant ati test exactly which pipes are bad or do they only have the ability to test them in quads? what if 1 pipe in each quad is bad?

[schuey74]

Originally posted by Geforce4ti4200
cant ati test exactly which pipes are bad or do they only have the ability to test them in quads? what if 1 pipe in each quad is bad?
ATI may have the capability to test each individual pipe, but the design of the VPU may make it impossible for them to break up the pipes into anything more than quads. In the case of one dead pipeline per quad then they'd probably just have a useless VPU.

[Geforce4ti4200]

could be why they have chosen to start off with 16 pipes. good idea for them I say. If they started with 12, they would not end up with many that have 12 pipes, but starting with 16 guarantees them quite a few 12 and even more with 8. 3% from what I hear will have 16 pipes, but thats enough for ati as they sell 20 times more midrange and lowend as highend anyway. to have 12 pipes, up to 4 pipes in the same quad can be bad. if 2 pipes are bad but not in the same quad, they end up with 8 then. I guess ati will be seeing far more 8 pipe cards than 12 even. If 2 pipes are bad, theres a 75% chance itll not be in the same quad either.

[SnakeEyes]

What if they ARE capable of having up to 4 random pipes be bad, and still use the remaining 12? I mean, what if the only requirement is that there be exact multiples of 4 for the remaining hardware to work properly, because they have some way to direct which of the pipes gets used. (Stretching for this idea, I know, but it seems to me that some clever engineering should allow just that to happen).

In that case, there would be quite a few more successful 12x1 configurations out of those that don't make the ful 16 pipe configuration, without falling back to 8 or having a completely failed GPU.

[Morrow]

Funny how everybody thinks ATI will have problems receiving 12 working pipes out of 16 on their r420 wherethou nvidia should have no problems using all of their 16 pipes on the upcoming nv40.

[MUYA]

Originally posted by Morrow
Funny how everybody thinks ATI will have problems receiving 12 working pipes out of 16 on their r420 wherethou nvidia should have no problems using all of their 16 pipes on the upcoming nv40.

You should read some of Paul's or my or various other posts (here or other forums) in which doubts over yeilds of a 16 pipeline GPU is mentioned. No one is denying there won't be yield problems..there will be.

[Geforce4ti4200]

maybe Nvidia has better yields or perhaps they have 17 pipes just in case. One spare? also expect alot of 8 pipe fallbacks from those that didnt make 16 pipes. we can infer that 16 pipe cards will be the uber top dogs and not "that many" will be around plus if demand exceeds supply, just raise the price and make more profit. Could we be looking at a new high of $700+ for the absolute elite? Then those with 8 pipes will be perhaps $400 or so but alot slower, but still better than the $400 9800xt which will drop to $300? just me rambling a bit with speculating ;)

[thatdude90210]

Originally posted by Geforce4ti4200
maybe Nvidia has better yields
That would be a complete turnaround of the current situation... maybe they swapped layout engineering teams. :)