Nagorak said:
The fact that 9500s can be turned into 9700s by reactivating the 4 pipes, pretty much means that they are not defective at all, no?
If this can be done in software it is awesome! I think the time has come for me to buy a R9500 Amateur and I never thought I'd be interested in this card!!! 8)
It means that the ones they played with can, without noticible problems. That's no guarantee that every one can.
RussSchultz said:
And what gives you the idea that the failure mode will leave a considerable amount of bad chips (enough to base a product line on) that have failed leaving only (up to) 4 pixel pipes damaged, but everything else functions 100%?
The defect density quoted by fab houses is mostly a result of defects in the base (silicon) layers of the wafer. The metal layers are much easier to get right, and tend to have mistakes less often. Since individual defects (ones that do not ruin an entire wafer) tend to be small, their effect is usually on one signal or a couple of signals. While it is possible that a defect like that can ruin an entire chip, if you did the design with redundancy in mind, you can just shut off that part of the chip and you have a still functioning part. Processor vendors do this all of the time on things like cache memories - redundant bit lines or word lines or even whole redundant memories which are tested after being fabbed. The working ones are the ones selected for actual usage (sometimes by blowing fuses at wafer test, sometimes by software testing, it depends on the implementation). The theory for this is the same as testing both halves of a graphics pipe versus one half or the other, and determining which works. In the processor cache case, they build extra memories and only use the ones that work, so you might only have a 512KB cache even if 550kb of the cache might actually work. In the r300 case, if both work they enable both, if just one works they enable just one.
RussSchultz said:
My guess is the 9500 will die a quick death when the RV350 is born, but that's good for ATI--since their margin is likely much higher on the RV350.
That depends on what the rv350 really is. If it truly is 4p/128-bit, then the only thing the 9500 would have on it would be the ability to use 256-bit memory interface. Then it would become a race between the two to see if the potentially higher core and memory clocks on a 4p/128-bit beats the lower clocked 4p/256-bit.
As for margins, for parts that really are 8p capable, turning them into 4p parts would be a loser, but for the rejects that are really only 4p capable would normally be scrap, which gives you great margins.
I guess what we really need is for someone to buy up a bunch of the regular 9500s and try out the extra graphics. If on at least one of them enabling the extra pipes results in 3d functionality that is incorrect, then they really are using failed 8p parts in the 9500.
