4 ms·

The 3080 requires a 750W PSU, while the 3070 only requires 650W. Given I have a 650W, that might tip the scale for me.

arvinsim 6y ago
They did have a disclaimer that it depends on your PC configuration. If you run something like the Ryzen 3600, it might be fine.
gambiting 6y ago
These numbers never meant anything. I run a 1050Ti on a 200W PSU - nvidia recommends 450W minimum. Add the TDP of your GPU, CPU and add about 100W for accessories = what you actually need. Nvidia recommends a much more powerful PSU than needed just in case.
- phaus 6y ago
  Yea I think if you run the calculations and you have room you should be good if your PSU is just slightly above the power requirements. If you run an unusual amount of memory or HDDs/etc, you might want to calculate everything manually rather than just assume its 100 watts though. I have never had a PSU fail, but supposedly unlike pretty much every other component if it fails its possible it will destroy your GPU/CPU/MB so it makes sense to spend a little extra on a good PSU. Probably my best component purchase ever was a 1050W Modular PSU in 2014. It was an old model even then and apparently no one wanted 1000W+ power supplies back then because it was on clearance. It should still be good for a 3090 and probably even a 5090 when I upgrade again in the future. I paid far less than a 1000w PSU costs now.
- kllrnohj 6y ago
  > Nvidia recommends a much more powerful PSU than needed just in case. The two things to watch out for here are 1) Cheaper PSUs can't always actually hit their claimed wattage, particularly not in real-world heat scenarios 2) CPU & GPU both use the 12V rail for their power, and not all PSUs can deliver all the rated wattage on the 12V rail. Any decent to good PSU won't have either of those issues, most list their rated wattage entirely on the 12V rails these days. So for example let's assume 250w for the GPU average and 120w for the CPU average (turbo & boost & all that). A 400w PSU could technically do that, particularly since if your only drive is an SSD your "accessories" are basically a rounding error. But if we take this 400W PSU for example: https://www.newegg.com/coolmax-i-400-400w/p/N82E16817159140 https://www.newegg.com/coolmax-i-400-400w/p/N82E16817159140 it can only deliver 300W on the 12V rail. Not enough. By comparison this EVGA 450W PSU can do a full 450W on the 12V rail alone: https://www.evga.com/products/product.aspx?pn=100-BR-0450-K1 https://www.evga.com/products/product.aspx?pn=100-BR-0450-K1 That's a 150W useful difference in this scenario even though the "rated" power only differs by 50W.
- eMSF 6y ago
  I feel like this used to be more true in the past. These days CPUs can exceed their official TDP by quite a large margin, and while in theory they should only do so temporarily, many motherboards default to unlimited boost clocks. (Then again, perhaps you're never going to fully utilize both CPU and GPU at the same time...)
  - gambiting 6y ago
    That is correct. Nowadays a 75W TDP Intel CPU can use as much as 200W for short bursts. That wasn't the case in the past. However, it should still be possible to find out that maximum draw value for many motherboards and pick a PSU accordingly.
Macha 6y ago
This is likely a cautious recommendation on nVidia's part. A 2080 Ti + 8700k system used 450W (nvidia recommended a 650w psu). While high end CPUs have gotten a bit more power hungry with higher core counts on the 10900k/10700k/3900x/3950x, I'd be shocked if a 650W PSU couldn't handle a mainstream CPU + 3080. https://www.techspot.com/review/1701-geforce-rtx-2080/page4.html https://www.techspot.com/review/1701-geforce-rtx-2080/page4.... nVidia's recommendation is based on "we don't want people pissed off because they put it in a system with a 3990wx at the recommended PSU capacity and it didn't work"
- redisman 6y ago
  You can see on Nvidias product page they are calculating based on a 125W processor. My 3700X is 65W so I'll have enough room for a 3070 easily on a 600W PSU.
  - thirdsun 6y ago
    Just to clarify: Of course a 65W CPU will still consume more power due to bursts and boosts but as far as I know AMD has a hard limit of about 90W for their 65W-rated CPUs, which is reassuring. I‘m glad I opted for the 3700X during my last upgrade - very efficient CPU indeed.
- tobyhinloopen 6y ago
  Do note that a PSU running at max capacity might also cause a noisy hot PSU. Having some headroom might result in a quieter system
- shajznnckfke 6y ago
  My old theory was they add so much headroom that you might be able to add a second one later in SLI.
  - mike_hasarms 6y ago
    There is no SLI anymore
arduinomancer 6y ago
Heavily depends what else is in your system.

They did have a disclaimer that it depends on your PC configuration. If you run something like the Ryzen 3600, it might be fine.

gambiting 6y ago

These numbers never meant anything. I run a 1050Ti on a 200W PSU - nvidia recommends 450W minimum. Add the TDP of your GPU, CPU and add about 100W for accessories = what you actually need. Nvidia recommends a much more powerful PSU than needed just in case.

phaus 6y ago
Yea I think if you run the calculations and you have room you should be good if your PSU is just slightly above the power requirements. If you run an unusual amount of memory or HDDs/etc, you might want to calculate everything manually rather than just assume its 100 watts though. I have never had a PSU fail, but supposedly unlike pretty much every other component if it fails its possible it will destroy your GPU/CPU/MB so it makes sense to spend a little extra on a good PSU. Probably my best component purchase ever was a 1050W Modular PSU in 2014. It was an old model even then and apparently no one wanted 1000W+ power supplies back then because it was on clearance. It should still be good for a 3090 and probably even a 5090 when I upgrade again in the future. I paid far less than a 1000w PSU costs now.
kllrnohj 6y ago
> Nvidia recommends a much more powerful PSU than needed just in case. The two things to watch out for here are 1) Cheaper PSUs can't always actually hit their claimed wattage, particularly not in real-world heat scenarios 2) CPU & GPU both use the 12V rail for their power, and not all PSUs can deliver all the rated wattage on the 12V rail. Any decent to good PSU won't have either of those issues, most list their rated wattage entirely on the 12V rails these days. So for example let's assume 250w for the GPU average and 120w for the CPU average (turbo & boost & all that). A 400w PSU could technically do that, particularly since if your only drive is an SSD your "accessories" are basically a rounding error. But if we take this 400W PSU for example: https://www.newegg.com/coolmax-i-400-400w/p/N82E16817159140 https://www.newegg.com/coolmax-i-400-400w/p/N82E16817159140 it can only deliver 300W on the 12V rail. Not enough. By comparison this EVGA 450W PSU can do a full 450W on the 12V rail alone: https://www.evga.com/products/product.aspx?pn=100-BR-0450-K1 https://www.evga.com/products/product.aspx?pn=100-BR-0450-K1 That's a 150W useful difference in this scenario even though the "rated" power only differs by 50W.
eMSF 6y ago
I feel like this used to be more true in the past. These days CPUs can exceed their official TDP by quite a large margin, and while in theory they should only do so temporarily, many motherboards default to unlimited boost clocks. (Then again, perhaps you're never going to fully utilize both CPU and GPU at the same time...)
- gambiting 6y ago
  That is correct. Nowadays a 75W TDP Intel CPU can use as much as 200W for short bursts. That wasn't the case in the past. However, it should still be possible to find out that maximum draw value for many motherboards and pick a PSU accordingly.

Macha 6y ago

This is likely a cautious recommendation on nVidia's part. A 2080 Ti + 8700k system used 450W (nvidia recommended a 650w psu). While high end CPUs have gotten a bit more power hungry with higher core counts on the 10900k/10700k/3900x/3950x, I'd be shocked if a 650W PSU couldn't handle a mainstream CPU + 3080. https://www.techspot.com/review/1701-geforce-rtx-2080/page4.html https://www.techspot.com/review/1701-geforce-rtx-2080/page4.... nVidia's recommendation is based on "we don't want people pissed off because they put it in a system with a 3990wx at the recommended PSU capacity and it didn't work"

redisman 6y ago
You can see on Nvidias product page they are calculating based on a 125W processor. My 3700X is 65W so I'll have enough room for a 3070 easily on a 600W PSU.
- thirdsun 6y ago
  Just to clarify: Of course a 65W CPU will still consume more power due to bursts and boosts but as far as I know AMD has a hard limit of about 90W for their 65W-rated CPUs, which is reassuring. I‘m glad I opted for the 3700X during my last upgrade - very efficient CPU indeed.
tobyhinloopen 6y ago
Do note that a PSU running at max capacity might also cause a noisy hot PSU. Having some headroom might result in a quieter system
shajznnckfke 6y ago
My old theory was they add so much headroom that you might be able to add a second one later in SLI.
- mike_hasarms 6y ago
  There is no SLI anymore

arduinomancer 6y ago

Heavily depends what else is in your system.