Per finire solo una precisazione: l' X-BoX non monta una GF4 evoluta, ma una via di mezzo tra una GF3 e una GF4 (ad essere pignoli i dati tecnici rilasciati da NVidia e Microsoft fanno presupporre che l'NV2A sia una sottospecie di Ti4400).
No se così fosse allora il pixel shaders della Nv2a sarebbe lo stesso di quello della geforce3 invece quello della geforce3 non supporta il pixel shaders 1.1, 1.2 e 1.3 mentre quello della nv2a e della geforce4 si...a parte questo ti posto questa intervista ad un programmatore che spiega le funzioni aggiuntive della nv2a :
Just answer these simple questions:
The NV2A supports signed stencil buffer additions. The NV-30 supports signed stencil buffer additions.
Does the GeForce4 support signed stencil buffer additions?
Yes or no?
Now, the NV2A supports Accuview, and 4Xs FSAA. Does the GeForce3 support either of these features?
Yes or no?
If the NV2A has features which are not supported in the GeForce3, but are in the GeForce4, does that make it above the GeForce3?
If the NV2A supports features not in the GeForce 4, but are in the NV-30, does that make it above the GeForce4?
Altra intervista :
GSUK: Tell us about the Graphics Chip - is that still going to be the NV 25?
JA: Well what we've always called it officially is the NV2A. A lot of
people have called it the NV25, but nVidia told us to call it the 2A
instead and there are two reasons for that: one, the NV25 in the
event that nVidia wouldn't use that part would be a PC part and
it would be put in here. The second thing is the part that we have
in the box is not just a super clocked NV20 but it actually draws
some of the geometry features out of the NV30. So if you put a
label on it, it's really an NV27.5 or somewhere in that range in
terms of the family. But it doesn't really have an official name so
we're settling on the NV2A and calling it a day at that. As you
know we upped the CPU and downgraded the GPU recently but
we'll still have the three times performance we were shooting for.
http://www.google.it/search?q=cache:...t&ie=UTF-8
riguardo al pixel shaders :
tecnical question to the dev: the xbox nv2a support the pixel shaders 1.3 ?
I have this question : the xbox nv2a support the pixel shaders 1.3 ?
So basically the pixel shaders of the geforce4 and the nv2a are the same ?
thx
Bye !
Xbox is programmed at a slightly lower level than a PC, since although it is more or less a DX8 interface, some things are changed to be a closer match to exactly how the hardware works which gives a bit more flexibility. So they aren't quite the same thing as 1.3 shaders on the PC (you write them as 1.1 shaders with Xbox extensions) but they are functionally more or less the same thing. It is the same underlying hardware, after all (Xbox and GeForce4 are functionally equivalent), but the Xbox API lets you access a few things that you can't get at even with 1.3 shaders on a PC.
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Shawn Hargreaves
Lead Programmer, MotoGP
Quindi le Api dell' xbox sono delle librerie apposite, che offrono più effetti e flessibilità del ps 1.3 e sono anche più facili da usare...
La nv2a ha tutto ciò che ha una geforce4 , più funzioni aggiuntive, quindi poichè non sono le frequanze ma le caratteristiche a fare il chip , è a tutti gli effetti una versione avanzata della geforce4...come è sempre stato detto da Nvidia...
Ciao !