AMD Cayman info (or rumor)

[tajoh111]

i don't know why people expectations have changed from unrealistic performance to now unrealistic power usage. The card can be just a competitive card with good performance near, at or beating a gtx 580 with a relatively high power usage(still not as high as the gtx 580) which is completely believable and I think will happen. The 5870 has a power usage of 212 watts at peak in furmark and it's significantly lower in gaming, but if we are going to go by that method, so does the gtx 580. If we test during game sessions, the gtx 580 consumes around 225 watts as wizzards test show, while the 5870 consumes 144 watts. If by gaming tests, power consumptions goes up to 200 or 190 watts, this is completely believable for the 6970. However they don't look nearly as awe-inspiring while the gtx 580 is at 225. It's better power efficiency than the gtx 580, but not super incredible.

The only way your going to get close to that 150 watt number flopper(and you still won't reach it) is if you compare real world gaming scenarios running on the 6970, vs a gtx 580 running furmark which is hardly a fair comparison.

In a peak tests like furmark, there is no way the 6970 is staying under 200 watts. You guys have to remember the 2gb of slower ddr5 vs 1gb of slower ddr5 added 30+ watts to the power consumption of the 5870.

http://www.tweaktown.com/reviews/324...d/index17.html

The 6970's memory is significantly faster so it should add more than 30watts+. Lastly one of the most telling tales is the size of the chip and the frequency. This chip is larger than the 5870 and clocked higher. Ultimate if the 6970 has more efficient shader usage, power consumption should be going up considerably.

The reason why the 6870 is more efficient size wise compared to the 5870 and they have similar performance is because the 6870 is actually using its shaders, while a lot of the 5870 shaders are just idle. Hence when you run furmark which uses all the power a graphics card, the power consumption on the 5870 jumps from 144 to 212w or a 48% jump compared to the 6870 which jumps from 127 watts to 163 watts or a 28% jump.

They actually have similar performance per watt in gaming scenario's, furmark just shows how how efficiently those shaders are being used in games when you compare the two. The larger the difference between the two, the less efficient the shaders are being used.

If the 6970 has high performance, it's power usage should go up considerably if it is an efficient architecture because that performance is coming from shaders doing work rather than just idling. The cost of performance is energy and the 6970 is not all of a sudden going to outperform the 5870 in games by 30 or 40% and consume less power.

I noticed the r300 tag disappeared..

[zerazax]

i don't know why people expectations have changed from unrealistic performance to now unrealistic power usage. The card can be just a competitive card with good performance near, at or beating a gtx 580 with a relatively high power usage(still not as high as the gtx 580) which is completely believable and I think will happen. The 5870 has a power usage of 212 watts at peak in furmark and it's significantly lower in gaming, but if we are going to go by that method, so does the gtx 580. If we test during game sessions, the gtx 580 consumes around 225 watts as wizzards test show, while the 5870 consumes 144 watts. If by gaming tests, power consumptions goes up to 200 or 190 watts, this is completely believable for the 6970. However they don't look nearly as awe-inspiring while the gtx 580 is at 225. It's better power efficiency than the gtx 580, but not super incredible.

Because that's where the latest rumors from credible sources are pointing its power consumption at - credible people aren't just making it up out of nowhere at this point, with all the leaks. They're posted in b3d and ocuk and guru3d and some other places now. Whether that's rated vs. real in game remains to be seen. And 144 vs. 225 is a big deal because the 5870 is rated at 188W (so the Furmark ~200W peak isn't out of the range) and Nvidia's 580 at 240W - but Nvidia rates their GPUs differently than AMD (I don't want to rehash that argument, but it was explained quite well in this thread itself) - if the 6970 is RATED at 190W, then its actual power consumption will be quite lower - heck, even if its rated at 225W, using AMD's terms, its a significant drop

The only way your going to get close to that 150 watt number flopper(and you still won't reach it) is if you compare real world gaming scenarios running on the 6970, vs a gtx 580 running furmark which is hardly a fair comparison.

In a peak tests like furmark, there is no way the 6970 is staying under 200 watts. You guys have to remember the 2gb of slower ddr5 vs 1gb of slower ddr5 added 30+ watts to the power consumption of the 5870.

http://www.tweaktown.com/reviews/324...d/index17.html

The 6970's memory is significantly faster so it should add more than 30watts+. Lastly one of the most telling tales is the size of the chip and the frequency. This chip is larger than the 5870 and clocked higher. Ultimate if the 6970 has more efficient shader usage, power consumption should be going up considerably.

Yes and no - we don't know what they did in terms of streamlining power. Keep in mind Barts managed to get 90% of the performance of the 5800's with even less power draw - its hard to believe they didn't change some things over to Cayman - not to mention the whole power regulation thing they're incorporating. It's not going to be a flat 30W+ more

Also, the GDDR5 definitely will consume more power going from 1GB -> 2GB faster stuff, then again, better binned GDDR5 isn't going to automatically scale linearly either

The reason why the 6870 is more efficient size wise compared to the 5870 and they have similar performance is because the 6870 is actually using its shaders, while a lot of the 5870 shaders are just idle. Hence when you run furmark which uses all the power a graphics card, the power consumption on the 5870 jumps from 144 to 212w or a 48% jump compared to the 6870 which jumps from 127 watts to 163 watts or a 28% jump.

They actually have similar performance per watt in gaming scenario's, furmark just shows how how efficiently those shaders are being used in games when you compare the two. The larger the difference between the two, the less efficient the shaders are being used.

If the 6970 has high performance, it's power usage should go up considerably if it is an efficient architecture because that performance is coming from shaders doing work rather than just idling. The cost of performance is energy and the 6970 is not all of a sudden going to outperform the 5870 in games by 30 or 40% and consume less power.

No one is making (well, I guess flopper is) that the 6970 is going to consume less power - it is, however, possibly rated at the same power.

Going with the same numbers you're using, if 6970 really does get rated at 190W like some are claiming, we might expect a similar Furmark peak (lets go with your 212W) but its more efficient, so using Barts efficiency #, we get 165W in game for Cayman. Lets say 170W.

Still significantly lower than the 225W or so the 580 pulls in game

And that's assuming Barts even fixed utilization of its shaders in the same way you're thinking - AFAIK, they're still using the same 5D as Cypress, just the scheduler and depth of each row was changed. Not to mention we have no clue how the change to 4-VLIW changes power from 5 etc.

edit: Taking a look at the sources, they say 190W in game, rated at 250W. Much closer to the 225W or so for the 580 (although we'd have to have w1z do a comparison so we're using the same equipment/methodology to be more accurate), so it remains to be seen what performance level its at - the same guy who said 190W said it more or less matches the 580, just a few % points under on the overall average

If 6970 performs worse than GTX 580 I will be seriously disapointed, and AMD just lost a sale.

Can't really say AMD is responsible for hyped expectations when they haven't said a peep