Speed of floating point pixel format

Wes · 2003-09-26T05:56:45

hey anybody know what the speed hit for floating point buffers are (generally speaking)? It seems to slow right down to a crawl on my radeon 9600 when i use a pBuffer with a floating-point pixel type (64 bits) and resolution of 512x512. How do they perform on higher end cards?

Graphics and GPU Programming Programming

Started by _walrus September 22, 2003 07:58 PM

14 comments, last by _walrus 20 years, 7 months ago

Maximus

124

September 24, 2003 09:08 PM

Actually, the ram and core speed of the 9600 are not faster than the 9800 pro. The core speed and memory speed of the 9600 are 325mhz and 400mhz respectively, 380mhz and 680mhz for the 9800 pro.

The 9600 pro overtakes the 9800 pro in core speed by a tiny bit, however due to having half the memory bandwidth and half the rendering pipelines (as well as half the vertex pipelines), it still isnt nearly as fast.

Edit: This information is available on ATi's site

quote:From what i gathered it's a total new design than the r300.

Both the 9600 and 9800 use the r350 chip, which isnt a whole new design, rather its a slightly updated r300 spec.

-----------------------
"When I have a problem on an Nvidia, I assume that it is my fault. With anyone else's drivers, I assume it is their fault" - John Carmack

[edited by - Maximus on September 24, 2003 10:09:07 PM]

-----------------------"When I have a problem on an Nvidia, I assume that it is my fault. With anyone else's drivers, I assume it is their fault" - John Carmack

Ostsol

122

September 24, 2003 09:15 PM

Well, we''re getting off topic, but the Radeon 9600 uses the RV350 chip. It''s not so much stripped down as it is designed that way. In addition to having half the pixel pipelines and vertex engines of the Radeon 9800, it also does not support the F-Buffer, which (when ATI exposes it in the drivers) allows for potentially infinite shader lengths. As such, the RV350 really has more in common with the R300.

And, uh, I haven''t used float buffers either, so no help from me. . .

-Ostsol

_the_phantom_

11,263

September 24, 2003 10:38 PM

at the risk of pulling it slightly more offtopic, the f-buffer in the 9800 chips, is it the same kind of thing as is described here http://graphics.stanford.edu/projects/shading/pubs/hwws2001-fbuffer/ or is it something different?

Xai

1,851

September 25, 2003 12:43 AM

man, I hate half ass information ...

look people, these are the chips:

9500 pro - RV300 (really an R300 chip with modification)
9600 pro - RV350
9700 pro - R300
9800 pro - R350

no one has EVER said (or at least been close to correct) that any 9500 or 9600 is ever better than any 9700 or 9800 ...

the issue was only ever with the relationship between 9500/9700, 9500/9600, and 9600/9800

the 9700 came out first and them the 9500 a short time later ... the 9500 had some aspects disabled (and half the memory bus) ... both are / we''re produced on a .15 um technology. People found they could reenable all the Radeon 9700 features on the 9500 (except the memory bus, which simply wasn''t there).

The 9800 later came out to replace the 9700 and is almost the exact same chip as the R300, but produced on a .13 um technology, faster clocked, higher memory speed, and a more optimized anti-aliasing engine. Then the 9600 came out to replace the 9500. The 9600 is produced on a .13 um technology, and actuall has half the pipelines of the 9500 / 9700 / 9800 ... but runs faster than the 9500, and is much cheaper to make ... people must realized the 9500 was made to SELL to a lower market price, not actually produced much more cheaply ... much like the old Intel 486 SX (which was a 486 DX chip with disabled coprocessor). Please note that the value line Radeon 9200 is the replacement for the Radeon 9000, which is the exact same chip, without AGP 8X support. Both chips are NOT DX 9 parts, and both are almost exactly the same as the Radeon 8500LE, but are much cheaper.

Here are a few links:

http://www.anandtech.com/video/showdoc.html?i=1812

http://www.anandtech.com/video/showdoc.html?i=1821

if you read carefully, you see one place it says the Radeon 9800 is a .15 micron part, yet when first released it was announced as their first .13 micron part ... I don''t know whose right ... but I think it''s .13 um ... but it really doesn''t matter, just features and speed.

Ostsol

122

September 25, 2003 07:51 AM

quote:Original post by _the_phantom_
at the risk of pulling it slightly more offtopic, the f-buffer in the 9800 chips, is it the same kind of thing as is described here http://graphics.stanford.edu/projects/shading/pubs/hwws2001-fbuffer/ or is it something different?

Yep, that''s it.

-Ostsol

davepermen

1,047

September 26, 2003 05:56 AM

xai: only 9600 is .13.. 9800 is .15.

oh, and, if you overclock the 9600 (wich you can do very well as it is such a low power, low heat chip), you can get to the power of a 9700. by default. the 9600 is slower than the 9500, though..

If that''s not the help you''re after then you''re going to have to explain the problem better than what you have. - joanusdmentia

davepermen.net

If that's not the help you're after then you're going to have to explain the problem better than what you have. - joanusdmentia

My Page davepermen.net | My Music on Bandcamp and on Soundcloud

Speed of floating point pixel format

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Speed of floating point pixel format

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines