GF100 evaluation thread

Without knowing how much area the FP32 mul takes up as a fraction of die size, we don't know how much area the FP64 functionality takes up on top of that.

Bear in mind, by the way, that the cost to nVidia for going half-rate FP64 was almost certainly much less than ATI, for one simple reason: ATI has more math units in the same area, while nVidia relies upon more efficient execution on fewer units. The smaller number of units means that nVidia is spending more die area on getting the info to the math units themselves than ATI, which means increasing the size of those math units doesn't do as much.

 

Yes but it is likely that each nvidia ALU requires more area due to upsizing of transistors and/or increased pipe stages in order to run at ~2x the frequency. 1/4 rate like ATI does it should be able to be implemented with almost zero area increase while 1/2 rate requires 2x the multiplier area.

 

Well, if I'm reading the architecture specs right, ATI also has more than 3x the math units on a 33% smaller die (512 vs. 1600). Per die area, then, ATI has somewhere around 5x the the math units. I seriously doubt that the optimizations for higher clock rate take up 5x the die area.

 

"Not enough" is not accurate. Anandtech's 5870 crossfire test, showed that the 16X+16X vs 8X+8X configurations, have only 2-7% performance difference.

There are motherboards like the MSI Big Bang Trinergy (not to be confused with the Fusion) which sports a NF200 chip that gives a full complement of 32 PCIe 2.0 Lanes which can be divided at 16X+16X for the graphics cards (there's also the option for 16X+8X+8X). It works for both SLI and Crossfire and I should know since I own it as well as two 5850s.

The funny thing is that its cheaper than quite a few vanilla high end P55 mobos (vanilla=No NF200).

 

Just wanted to throw this out so I was being called out. I picked a random review (Firingsquad) and after running the numbers throw, results were:

GTX480 54% faster than GTX285
5870 60% faster than 4890

By the same yardstick that Cypress was concluded to be "meh", GF100 is less than even a "meh", "WTF" territory since its less Unless the obvious double standards show up again.

 

That's the problem. Hard numbers are important here! If it only cost them, say, 5% of die area vs. doing it ATI's way, then it really isn't a big deal, is it?

It might be substantial as a fraction of the die area allocated to the math units themselves, but if nVidia's math units take up less than half the die area of ATI's, then it's a much lower total cost than if ATI had tried the same thing. That's what I'm trying to say.

 

... How much time after the 4890 launched did the 5870 launch? Now do the same for the GTX 285 vs the GTX 480. 4890 ---> 5870, ~6 months. GTX 285 ---> GTX 480 ~15 months. Maybe thats the problem.

 

Didnt you know, time is irrelevant. (along with money, power, heat & noise)

Shame on ATI for launching so soon. Investing in AMD gpus is a bad idea since they get outdated pretty quickly.

 

Do you really believe that back in September they didn't know they wouldn't make it for October launch? Yet all those statements quoted before were made after Cypress' launch.

 

AFAIK, Cypress != Hemlock, so fastest graphics card after Cypress is correct. After Hemlock, only fastest GPU makes sense...

Anyway, whatever...enough with this. It's quite pointless to discuss anything when the people involved have their minds set on something completely different.

 

I'm sure it is about conditioning in relation to "meeting expectations". For the 58xx series it met expectations on performance in the most and also exceeded them in the power and temp case. Therefore people were conditioned for lower temp and power on the smaller process, hence why they now feel disagreeable to 4XX's extra temps and power. If 58XX had still been as hot as 4XXX series it wouldn't be so much of a big deal.

That's the problem when you come out of the blocks 2nd, you are a lot more likely to disappoint than to blow people away.

 

Indeed, though I am also beginning to suspect that nVidia missed their performance target somewhat with this part. Here's hoping that later iterations of the chip have significantly higher performance per die area (and per watt...).

 

I think it's obvious that they did missed their targets. Clocks are certainly not high enough (especially compared to GT200b) and they certainly didn't want to come out with their flagship with units disabled. Both would without a doubt, increase performance, had they been possible.
Still, power draw is the biggest problem I see that they need to address in future iterations. If the GTX 480 had less power consumption under load (let's say 50w), the results would be far more appealing.

 

Tech-Report has yet to publish their review. Was hoping to see it yesterday, but nothing...

Btw, is Rys working with Scott on this one ? (Since he had written a piece for TR a while ago)

 

Yield numbers in the 70% range are what I've heard through the grapevine, and make far more sense economically than some of the more ridiculous estimates out there.