320 stream processors

[j1979]

if the new hd 3800 cards have 320 stream processors, how come they are slower than the 8800gt 256mb and the 512mb?

does anyone know the significance of having almost 3 x the amount compared to Nvidia's offerings, does it depend on the way software is written?

 

[Battleneter2]

Completely different architecture. There is no realistic way to compare, but a dumb down way of putting it is the Nvidia SP does around 3x the work, where ATI have opted for more in there architecture.

You cannot compare clock rates either, so do not try and compare specification ATI vs Nvidia, it is pointless. The only thing you can compare is performance, which is of course all that counts anyway.

 

[Cali3350]

Compare performance. Period. These chips are made in totally different ways.

 

[pxc]

http://www.cs.uaf.edu/2007/fall/cs441/proj1notes/favier/

See the GPU Architecture section.

 

[BullseyeBob]

Don't ATi's shader clocks run at the same as the core? Where as Nvidia's shaders run at a much much higher speed than the core? If this is correct it could explain why ATi needs more shaders to compete.

 

[alg7_munif]

Don't forget to compare the price too.

 

[Obi_Kwiet]

Because ATi cards really only have 64 Shader Processors that are supposed to be able to do five operations per clock if the planets align.

 

[azuldenial]

Don't forget to compare the price too.

That's true, but in this case, you get what you pay for, performance-wise.

 

[pxc]

Because ATi cards really only have 64 Shader Processors that are supposed to be able to do five operations per clock if the planets align.

waffles

Kind of worked out as well as 3 texture units per pixel pipeline back in the Radeon 7500 days.

 

[Mr. Bluntman]

Because ATi cards really only have 64 Shader Processors that are supposed to be able to do five operations per clock if the planets align.

LOL

And how often does that happen?

IIRC, each of the 80 SP blocks has one general purpose FPU that can do any type of floating point op, while the other four can only do MADD ops (multiply + add). Even if they can all be utilised by your shader programs, chances are the architecture will be hamstrung by the lack of ROPs and TMUs present.

waffles

Kind of worked out as well as 3 texture units per pixel pipeline back in the Radeon 7500 days.

Mmmmmm. Waffles. /drool

 

[Manny Calavera]

LOL And how often does that happen?

.



Mmmmmm. Waffles. /drool

Whenever its running Call Of Raurez,or recent ATI demos.