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View Full Version : NV25 - what was added?


DIMA
08-09-02, 12:07 PM
I recall there was a post in the old forums that had a list of additions added to NV25 over NV20 with just an increase of 3 million transistors.

Don't really remember who posted it, but I would REALLY appreciate if someone could make this list again (in his mind:) ) and post it here.

Also, any material about this is VERY welcome! :)

SurfMonkey
08-09-02, 12:30 PM
They added a vertex shader and made a few changes to the LMA architecture. Also Quincunx was added and the AA overhauled. The visibility sub system was also given a polish and the caches increased in size (I think).

DIMA
08-09-02, 12:37 PM
Originally posted by SurfMonkey
They added a vertex shader and made a few changes to the LMA architecture. Also Quincunx was added and the AA overhauled. The visibility sub system was also given a polish and the caches increased in size (I think).

Thx M8! :D

But that wasn't really what I was looking for as I was well aware of these changes in general terms, since they were pretty much described by many sites in their GF4TI previews.

What I was looking for is a complete list of all the addition as was once present in the old forums.

SurfMonkey
08-09-02, 01:02 PM
OK, have a look at this (http://www.xbitlabs.com/video/geforce4/) then. It's a pretty good run down of the additions n stuff.

The Processor
08-09-02, 02:59 PM
Originally posted by DIMA
A very good & informative read, although...

Although it isn't what you are looking for. It is also a bit incorrect.

The 8500 does not do multi-sampling...

DIMA
08-09-02, 03:16 PM
Originally posted by The Processor


Although it isn't what you are looking for. It is also a bit incorrect.

The 8500 does not do multi-sampling...

Honestly, I never really liked their reviews and this review is no exception.

Steppy
08-09-02, 03:51 PM
Originally posted by SurfMonkey
They added a vertex shader and made a few changes to the LMA architecture. Also Quincunx was added and the AA overhauled. The visibility sub system was also given a polish and the caches increased in size (I think).

Quincunx was already in the NV20. The second VS and the 4xS AA mode plus some tweaks were all that was added for NV25 from NV20.

DIMA
08-09-02, 04:01 PM
Originally posted by Steppy


Quincunx was already in the NV20. The second VS and the 4xS AA mode plus some tweaks were all that was added for NV25 from NV20.

Quincunx was indeed already in NV20, but it's implementation was much approved in NV25 (sample patters were moved) and the perfomance hit was much lower than on GF3.

In general terms, yes, the things u mentioned were the only things added to NV25, but when u dig in a bit deeper, you'll see that it's not that simple...

That's why I want that list! :)

Nutty
08-09-02, 06:21 PM
I thought Gf3 only did pixel shader 1.1?

Gf4 added some depth changing functions to the pixel shader, and it also added NV_point_sprite functionality. This is not available on gf3.

As far as developer features go, I think those are the only changes between nv20, and nv25. This is based on OpenGL extensions.

The Processor
08-09-02, 06:41 PM
Originally posted by Steppy
The second VS and the 4xS AA mode plus some tweaks were all that was added for NV25 from NV20.

Don't be forgetting deepened caches...

StealthHawk
08-09-02, 09:25 PM
Originally posted by Nutty
I thought Gf3 only did pixel shader 1.1?

Gf4 added some depth changing functions to the pixel shader, and it also added NV_point_sprite functionality. This is not available on gf3.

As far as developer features go, I think those are the only changes between nv20, and nv25. This is based on OpenGL extensions.

correct. GF3 only supported PS 1.0 and 1.1

GF4 added support for PS 1.2, 1.3. also added were accuview AA hardware to assist with FSAA.

4xS was already available with the GF3 if you used a tweaker. GF4 drivers just added it to the control panel.