Why does AMD require 2x wattage? Long term costs

[BCShak]

Reading the reviews of AMD vs nVidia chipsets, the cost of AMD would make it a more bang for buck card, however I noticed that the power consumption of say the R9 290X is 2x+ that of the GTX 970, yet the 970 is considered the better performer.
Extra wattage means more heat, it also means a bigger PSU which means more heat and more $$ to pay for the extra power than if you would use the 970, especially in sli/crossfire modes.
Extra wattage means a higher electric bill, for the PC and the AC when you shouldnt be using your PC as a grill.
In the long term I think the cost of AMD vs nVidia at best is negligible. Im indifferent to either brand, I just want the best value/performance ratio.

Im not a physicist but can someone explain why AMD cards need that much power? With that much power why isnt there a substantial performance difference btw the cards? (nVidia works smarter, AMD works harder?)

Im just curios

 

[RaDiKaL_]

"(nVidia works smarter, AMD works harder?)"

At least for this current gen of cards yes, nvidia's offerings are more efficient, so AMD in order to keep up with the performance of their competition they had to use more power to balance the field. That's why the GTX 970 gets the recommendation every time at that price point, even with the "vram bug" recently found.

 

[TechyInAZ]

Maxwell (GTX 900 series) is very new, which is why they consume hardly any power.

AMD's R9 GPUs are older so they require more power.

I would get the gtx 970, newer and faster than the r9 290X while simultaneously consuming less power

 

[LightSwordM]

That is true, up to an extent. First, due to a recent issue(cough, cough, 3.5 GB VRAM, even though I have it), it's performance is being reduced. Second, at higher resolution, because of the 256-bit memory bus, it is limited in terms of bandwidth, and because compression works to an extent, the r9 290/r9 290x begin crushing it at higher resolution(essentially tying with the GTX 980, even surpassing it in 4k).

However, because it is much more efficient, SLI-setups have become even easier than with the bridgeless CrossFireX. It consumes less and outputs less heat.

 

[HEXiT]

the gtx 970 has a much more efficient power delivery. it turns off anything its not using or switches it to low power. while the amd cards dont.
it sorta works like this...
in very basic terms:
the nvidia gpu wants to place a poly on screen and uses 1 shader to do it, while it works away with the 1 shader the other 100+ are turned off until there needed.
the amd chip doing the same task will use the 1 shader but will be delivering power to every other shader as well. end result higher overall power consumption.

 

[BCShak]

so nVidia works smarter. but when the cards are on full load, the power consumption should be comparable except the AMD still uses more juice. At least as shown in this site http://www.forbes.com/sites/antonyleather/2014/11/27/leaked-performance-numbers-of-amds-r9-390x-should-nvidia-be-worried/
And I saw other graphs but can't seem to find the site for those.

Again, I'm indifferent to either companies but running some math based on my power usage, at $0.16kWh, running at 2hrs per day, a 841watt AMD Crossfire MSI 290X setup would cost me $32.58 more annually than a MSI 980 Sli. The build difference is $465 for the 980 but assuming it will last me 3 yrs, the $97.74 saved from power consumption would make an Sli setup only $367.26 more than the 290X.
This is without considering taxes (pay more for the AMD) and cost of extra AC cooling in the hotter months. Eyeballing the figures, pricewise these two are almost on par. There's of course more than just cost (I find hot PC's just uncomfortable and I hate nVidia's shady corporate ways with gsync and the 970 fiasco)
According to this http://www.trustedreviews.com/opinions/nvidia-geforce-gtx-980-v-amd-radeon-r9-290x_Page-5
since I'm going 1440p, choosing between these two is a tough choice...

Update: this was the other site mentioned
http://www.hardocp.com/article/2014/10/27/nvidia_geforce_gtx_980_sli_4k_video_card_review/10#.VMmgkWjF_KE

 

[leeb2013]

Gtx 970 has half a GB less ram to power lol

 

[chenw]

The classic "Optimisation" vs "Brute force" comparison.

 

[renz496]

Maxwell (GTX 900 series) is very new, which is why they consume hardly any power.

AMD's R9 GPUs are older so they require more power.

I would get the gtx 970, newer and faster than the r9 290X while simultaneously consuming less power

and yet both are based on the same TSMC 28nm node.

 

[renz496]

Reading the reviews of AMD vs nVidia chipsets, the cost of AMD would make it a more bang for buck card, however I noticed that the power consumption of say the R9 290X is 2x+ that of the GTX 970, yet the 970 is considered the better performer.
Extra wattage means more heat, it also means a bigger PSU which means more heat and more $$ to pay for the extra power than if you would use the 970, especially in sli/crossfire modes.
Extra wattage means a higher electric bill, for the PC and the AC when you shouldnt be using your PC as a grill.
In the long term I think the cost of AMD vs nVidia at best is negligible. Im indifferent to either brand, I just want the best value/performance ratio.

Im not a physicist but can someone explain why AMD cards need that much power? With that much power why isnt there a substantial performance difference btw the cards? (nVidia works smarter, AMD works harder?)

Im just curios

let just say that nvidia have the money to fund their R&D more than AMD hence they were able to make noticeable progress even if they were held back by the same process node.