NV48 Cancelled

[hovz]

now that we see the r480 is basically the same speed as the r420, nvidia doesnt need to release an nv48.

 

[Bob]

2. FP blending (pretty much broken on the NV40).

Care to share the details?

 

[hovz]

supposedly the performance hit of fp blending is much lower on the 6600 because it was broken on the 6800

 

[mozmo]

It would be disappointing if nvidia didn't release a refresh that sported bug fixes (video processor/fps blending) and core effeciency improvments. Also having a native pci express card would be nicer than a bridged agp part.

 

[Ostsol]

Yeah, that alone would certainly make it worth it even without a performance increase -- as long as there's no decrease, of course.

 

[AndrewM]

2. FP blending (pretty much broken on the NV40).

eh?

 

[Smurfie]

Over here in Asia, all I can find are MSI, Asus and Leadtek 6800GTs and 6800 Ultras. They are easily available, and you can just walk in a store, pay and walk out with an Ultra even. There is no chance of finding any BFG, Gainwards or XFXs here. And I know I badly wanted a BFG.

Yes. And I assume you were hankering after the BFG as it provides a default higher speed out of the box whereas the others don't?[/quote]

Yup.

But I ended up with a Leadtek 6800nu anyway.

 

[KimB]

Functional, but performance is way lower than it should be. Dig up some Far Cry 1.3 benchmarks that compare HDR rendering with the NV40 (GeForce 6800 variants) and the GeForce 6600.

 

[Bob]

Functional, but performance is way lower than it should be. Dig up some Far Cry 1.3 benchmarks that compare HDR rendering with the NV40 (GeForce 6800 variants) and the GeForce 6600.

FP16 blending runs at "half speed". This means 4 pixels/clock on NV40, and 2 pixels/clock on NV43. There's isn't enough memory bandwidth otherwise.

Consider: 4 pixels/clock * 4 component * 2 bytes/component * 2 (blending) = 64 bytes/core clock. The clock runs at 400-450 MHz (depending on model - say 400 MHz), that's 25.6 GB/sec for blending alone (ignoring texturing, Z/S, multisampling, or whatever else). The memory banwidth available to an NV40 Ultra is 550 MHz * 256 bit DDR = 35.2 GB/sec.

This means that if all memory bandwidth would be used up solely for blending, and you could only afford 5.5 pixels/clock of FP16 blending. Rounding that down to 4 pixel/clock to saves a lot of hardware at marginal speed cost for a feature that's little used.

Another thing to consider is that HDR rendering is not -only- FP16 blending. FP16 texturing also costs memory bandwidth, texture filtering time, and other datapath resources, compared to plain 8-bit texturing.


Of course, your simplistic claim that it's somehow broken makes so much more sense.

 

[AndrewM]

Functional, but performance is way lower than it should be. Dig up some Far Cry 1.3 benchmarks that compare HDR rendering with the NV40 (GeForce 6800 variants) and the GeForce 6600.

It just looks like it drops off in performance. I wouldn't say that it's broken tho.

Same deal with things like regular blending dropping in performance too. (works like an 8 pipe{ROP} chip, right?)

 

[Guden Oden]

So what's the deal here, will NV release a 16-pipe high-end chip with native PCIe and fixed video processor, or won't they? Can someone summarize please.

 

[ChrisRay]

Aren't they primarily North American vendors?

Yes they are. But they dont produce high volume retail cards either as far I have ever seen. Leadtek has always been a kind of 'enthusiast" brand around here.

PNY/BFG/EVGA all ship the reference cards like mad to retail channels though.

 

[Dave Baumann]

Yes, but primarily to the North American market. Market opportunity there is suprisingly small when compared to the rest of the world.

 

[ChrisRay]

Yes, but primarily to the North American market. Market opportunity there is suprisingly small when compared to the rest of the world.

Are you saying Leadtek is a heavy retail seller in well Europe? Thats sorta surprising. But US retail volume should also be considered as well because it has to be significant as well. ((I mean hey they are easiest to get in the states as far I have seen))

 

[Fodder]

Are you saying Leadtek is a heavy retail seller in well Europe?

I don't know about Europe, but I can confirm that they're one of the most widespread brands in Australia and Asia.

 

[_xxx_]

Yes. And I assume you were hankering after the BFG as it provides a default higher speed out of the box whereas the others don't?

Asus also has some souped-up editions with higher clocks, as well as some other manufacturers. For European folk: on www.alternate.de (the biggest online shop in Germany), all GPU/RAM clocks are listed for every card, so it's easy to find out which ones are higher clocked.

 

[godog]

nv ho lun nor bao site!!!!

 

[trinibwoy]

nv ho lun nor bao site!!!!

did you just put a curse on beyond3d? cool

 

[DegustatoR]

It would be disappointing if nvidia didn't release a refresh that sported bug fixes (video processor/fps blending) and core effeciency improvments. Also having a native pci express card would be nicer than a bridged agp part.

That'll be NV47 if NV48 is indeed cancelled. Not sure that NV48 is worth it anyway, maybe they've decided to fasten NV47 introduction instead of NV48 launch in 1Q05...

 

[Xmas]

Functional, but performance is way lower than it should be. Dig up some Far Cry 1.3 benchmarks that compare HDR rendering with the NV40 (GeForce 6800 variants) and the GeForce 6600.

This one?

http://www.xbitlabs.com/articles/video/display/farcry13_7.html

I always wondered what that * means there... not sure they're actually comparing the same thing.