Avagy az NV3X...
Ha netán törlödne a hozzászólásod, csak csekkold ezt: #1940
Ha netán törlödne a hozzászólásod, csak csekkold ezt: #1940
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Borg #2113 A topic elején ki lett tárgyalva, olvass vissza.
Itt az eredeti fejtegetés:
"At the moment, the NV30 is slightly faster on most scenes in Doom than the R300, but I can still find some scenes where the R300 pulls a little bit ahead. The issue is complicated because of the different ways the cards can
choose to run the game.
The R300 can run Doom in three different modes: ARB (minimum extensions, no specular highlights, no vertex programs), R200 (full featured, almost always
single pass interaction rendering), ARB2 (floating point fragment shaders, minor quality improvements, always single pass).
The NV30 can run DOOM in five different modes: ARB, NV10 (full featured, five rendering passes, no vertex programs), NV20 (full featured, two or three
rendering passes), NV30 ( full featured, single pass), and ARB2. The R200 path has a slight speed advantage over the ARB2 path on the R300, but only by a small margin, so it defaults to using the ARB2 path for the quality improvements. The NV30 runs the ARB2 path MUCH slower than the NV30 path. Half the speed at the moment. This is unfortunate, because when you do an exact, apples-to-apples comparison using exactly the same API, the R300 looks twice as fast, but when you use the vendor-specific paths, the NV30 wins.
The reason for this is that ATI does everything at high precision all the time, while Nvidia internally supports three different precisions with different performances. To make it even more complicated, the exact precision that ATI uses is in between the floating point precisions offered by Nvidia, so when Nvidia runs fragment programs, they are at a higher precision than ATI's, which is some justification for the slower speed. Nvidia assures
me that there is a lot of room for improving the fragment program performance with improved driver compiler technology."
A lenyeg: az ARB2 versus NV30 proprietary extensions path.
Az NV30 sajat kodjat hasznalva KETSZER olyan gyors lesz, mintha general ARB2-t hasznalna. Ugyanez a 2x gyorsasag egy egeszen kicsivel gyorsabb, mint a 9700 a general ARB2vel. Erdekesnek tunik, de logikus a magyarazat : az NV30 tobb precizitassal szamolha: 12bit, 16bit es 32bit. A 12 kiesik, mert az fixed, marad a 16 es 32 bit float.
Na most a Radeon 9700 MINDENHOL ezektol elteroen, 24 bit float-ot hasznal.
[b]A fentiekbol egyertelmuen a kovetkezik: ha a standard, general ARB2 path jatszik, akkor az NV30 tutira 32bites (per channel, ugye) precizitassal szamol - amitol bitang kurva lassu lesz a 9700-hoz kepest, hiszen az - ugye, ezt mar tudjuk - MINDIG ugyanazon a 24biten oszt/szoroz.
Ha viszont az NV30-as sajat path jatszik, akkor TUTIRA 16 bites mindossze, ami viszont lathato minosegromlast eredmenyez - igaz, igy mar egy arnyalatnyit gyorsabb lesz a Radeonnal.
Konkluzio: szarabb kep es par szazalek sebessegelony KONTRA Radeon-szintu avagy ta'n szebb (bar senkinek nincs szuksege 4*32bitre, meg JCnek sem, tuti) minoseg, sokkal lassabban a 9700nal - ezek a leendo NV30-tulajok kilatasai D]|[-ugyben.
PS: azt mar meg sem merem emliteni, mi marad abbol a rosszabb/gyorsabb kombobol az NV30-on, ha bekapcsolunk majd egy 4XAA-t pl...
"
Amúgy itt egy kis csemeg az AFezőknek:
4XAA,8XAF
5900U/9800PRO
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