X1900GT

  • Thread starter Thread starter Neil
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Neil

I was going to get an X1800-summat-or-other for my next card,
that is until I noticed the X1900GT. I thought, "That looks ok,
it seems to have some features that the X1800's don't, and the
price is about right, and someone's bound to find a way of
unlocking it into an XT." I'm not quite ready to buy yet, but
when I had another look, they seem to have disappeared from the
on-line catalogues I look in. Have they been taken off the
shelves? (They're still listed on ATI's site). Is it a
coincidence that they've disappeared now that someone claims to
have found a way to unlock (at least some of) these cards? (Has
everyone just rushed out and bought them all up hopeful of a
cheap XT?)

Neil
 
First of One said:
http://www.pricegrabber.com/search_attrib.php?page_id=5&form_keyword=x1900gt&rd=1
Click to expand...

Hmm £190. I'm sure they were only £130 when they first
appeared. People must have been snapping them up.

Has anyone with more patience than I have waded through the
million pages of forum posts on unlocking? Is it still true
that there are/were two core versions only one of which is
unlockable? And if it is true, is the unlockable core still
shipping, or are they permanently locked now?

Neil
 
Supply and demand. Remember, the whole reason for the X1900GT's existence,
at least in the beginning, is for ATi to recycle rejected X1900XT cores that
do not have all 16 pipes operational. As yields improve, *expect* fewer and
fewer unlockable X1900GT cards.
 
First of One said:
Supply and demand. Remember, the whole reason for the
X1900GT's existence, at least in the beginning, is for ATi to
recycle rejected X1900XT cores that do not have all 16 pipes
operational. As yields improve, *expect* fewer and fewer
unlockable X1900GT cards.
Click to expand...

I don't get that. If X1900XT chips fail they get put into GT's
(I get that). But surely the failed ones, even if they can be
unlocked (because they are the right core type), can't be
usefully unlocked, because the locked-out sections don't work.
If the manufacturing yield goes up, there will be more fully
operational XT chips, but there will still only be a market for
a similar number of XT cards. The excess chips will still have
to go into GT's, but this time unlocking them would be a useful
thing to do because it actually yields a working XT. I wouldn't
have thought that ATI would use the improved yield to make fewer
XT cores and switch the remaining production over to permanently
unlockable GT cores. They certainly didn't seem to do that in
the "old days". E.g. all the 9800Pro's from a certain period on
had the same core as the 9800XT, and they were all (pretty much)
fully functional. (I have one working in this machine here).

How do you work out that improved yields will mean fewer
unlockable GT's?
 
Neil said:
I don't get that. If X1900XT chips fail they get put into GT's (I get
that). But surely the failed ones, even if they can be unlocked (because
they are the right core type), can't be usefully unlocked, because the
locked-out sections don't work.
Click to expand...

Correct, though keep in mind the chips are probably batch-inspected, so some
with functional pipelines manage to slip through. It's also possible to have
units with 16 functional pipes, but cannot reach the XT's clock speed.
If the manufacturing yield goes up, there will be more fully operational
XT chips, but there will still only be a market for a similar number of XT
cards. The excess chips will still have to go into GT's, but this time
unlocking them would be a useful thing to do because it actually yields a
working XT. I wouldn't have thought that ATI would use the improved yield
to make fewer XT cores and switch the remaining production over to
permanently unlockable GT cores.
Click to expand...

Keep in mind a crippled XT chip costs as much to produce as a fully
functional one. As yields improve, it doesn't make economic sense for ATi to
continue producing an expensive chip only to equip it in a lower-cost video
card. Most likely ATi would cut back production of XT chips, and ramp up
dedicated GT chips, fitting more chips on a wafer.

Apparently the foundries are pretty flexible with design changes, with lead
times as little as 30 days. With the X800, ATi had separate designs for the
AGP and PCIe cards and adjusted production quantities according to demand -
it was deemed cheaper than using a unified design and spending extra $5 for
the AGP bridge chip.
They certainly didn't seem to do that in the "old days". E.g. all the
9800Pro's from a certain period on had the same core as the 9800XT, and
they were all (pretty much) fully functional. (I have one working in this
machine here).
Click to expand...

Yep, my friend has one, too, complete with the 9800XT PCB and temp sensor.
However, the R360 core was no more expensive to produce than the R350 core,
having identical features and pipelines. (It may even be cheaper.) The
primary cost driver behind the 9800XT was faster RAM and a better heat sink.

A better example would be the 9500 Pro, made using crippled 9700 cores.
Eventually production was just discontinued, superceded by the cheaper (and
slower) 9600.
 
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