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View Full Version : OT: 64 MB or 128MB card? (3D textures)



V-man
07-02-2003, 04:00 AM
I'm asking here cause some people have tried and know about which cards can do what?

It looks like the R 9500 and R 9700 report as supporting 2048 x 2048 x 2048??? I wish! Even in software, I would not have enough RAM!

The FX 5200, 5600, 5800 says 512x512x512. I still wish!

The above comes from http://www.delphi3d.net/hardware/listreports.php

Even with GL_LUMINANCE as an internal component, it will take 128MB to store a 512x512x512

I don't see any cards that have 256MB onboard and probably would be too expensive.

I'm assuming all the cards can do in hardware if they have 128MB

512x512x256 x 1byte = 64MB ????????

Mezz
07-02-2003, 04:11 AM
Yeah the Radeons report 2048x2048x2048. Thats like 8 gigabytes with just 1 byte/pixel. I don't know what you'd fill a 2048^3 texture with though.

However, I perhaps there are uses for having the 2048x2048 part, then perhaps only small levels of depth (say 8 or 16)?

On your other point, there are Radeon 9800s and FX 5600/5900s that are hitting the market with 256MB RAM. Price seems around 400(UK), don't know about other countries.

-Mezz

EG
07-02-2003, 04:20 AM
>Even with GL_LUMINANCE as an internal component,
>it will take 128MB to store a 512x512x512

There are some texture compression formats that were defined for 3D textures, IIRC achieving compression ratio up to 8:1.
The ATI board may have a higher compression scheme (?).

>I don't see any cards that have 256MB onboard and probably would be too expensive

My local reseller has several 256 MB... lemme check... 256MB GF 5600 at 180 Euros, 128MB model at 160. Not too expensive, and rather makes the 128MB model not that interesting.

V-man
07-02-2003, 04:51 AM
Oh yes! I always forget about compressing.
So it should fit if you can compress 512^3 x 1 bytes a tiny bit even.

I would feel comfortable having support for 1024^3 just to play around with.

PS: just saw a FX 5600 256MB 255$CAN. It's a good price actually.

Zeno
07-02-2003, 08:28 AM
Don't forget that the largest 3D texture a 128MB card can hold is actually less than 128 MB. The whole texture has to fit in video memory at once and a 128 MB texture cannot do that on a 128 MB card since there has to be room for framebuffer and stuff.

Also, I've found that our 256 MB ATI FireGL X1 can't upload a 128 MB texture (which sucks cuz that's the main reason we bought it and its an expensive card), but our 256 MB FX5600 can.

Lastly, GL_RGB is stored internally as GL_RGBA, so you won't get any savings that way.

-- Zeno


[This message has been edited by Zeno (edited 07-02-2003).]

davepermen
07-02-2003, 08:46 AM
don't forget that max width,height,depth don't mean you need to use all of them at the same time..

but is it possible on a gf, to have say a 1024x64x64 box? i doupt it, as they say 512 is limit (but i don't KNOW it, okay?! http://www.opengl.org/discussion_boards/ubb/biggrin.gif)

so you could use the 2048x.. on the ati as well.. possibly not for the cubic volume, but at least for box-volumes..

anyone knows more about this?

this _could_ be the difference..

and yes, there are 256mb cards out...

Zeno
07-02-2003, 09:12 AM
Originally posted by davepermen:

but is it possible on a gf, to have say a 1024x64x64 box? i doupt it, as they say 512 is limit (but i don't KNOW it, okay?! http://www.opengl.org/discussion_boards/ubb/biggrin.gif)


Yes, 512 is a hard limit on any single dimension on the NVIDIA cards.



so you could use the 2048x.. on the ati as well.. possibly not for the cubic volume, but at least for box-volumes..

That is correct. You could have a 2048x16x16 texture if you wanted on an ATI card.


this _could_ be the difference..

Could be what difference?



[This message has been edited by Zeno (edited 07-02-2003).]