Nvidia clarifies power supply requirements for RTX 40-series

AlphaX

Posts: 57   +16
Staff
The big picture: Since the announcement of Nvidia's RTX 40-series graphics cards, some consumers have been curious or even worried about their power supply, wondering if it can safely run a new GPU. Thankfully, Nvidia has cleared the air and reassured users regarding the power requirements for its cards.

When Nvidia announced its upcoming RTX 40 series graphics cards, it confirmed that every Ada Lovelace card would use the new ATX 3.0 compliant 12VHPWR cable. This cable can supply up to 600W, which is 4x the wattage of a traditional 8-pin PCIe cable. It also has four "data" pins, which allow the power supply to communicate directly with a GPU.

Nvidia revealed power draws for each of the three graphics cards. The RTX 4090 has a TDP of 450W, the RTX 4080 16 GB draws 320W, and the RTX 4080 12 GB pulls up to 285W. It recommends power supply wattages of 850W, 750W, and 700W for each of the three GPUs. However, the company says the new graphics cards will still work with ATX 2.0 power supplies.

Manufacturers will include an adapter with either three 8-pins or four 8-pins to a single 12VHPWR cable, allowing consumers to use the GPUs on older power supplies. However, PCI-SIG believes these adapters could potentially cause issues for some users.

A report from PCI-SIG warned of potential over-current and over-power risks with the adapters. An Nvidia FAQ rebutted the warning saying that while the concerns are legitimate, the adapters should not affect its new cards. The company claims that these were simply a "potential issue with a prototype connector" that it fixed before the official launch of the graphics cards.

The bottom line is as long as the power supply meets the GPU's wattage requirements, there is no reason to worry about using an ATX 2.0 power supply adapter with the latest graphics cards. Nvidia has fixed them so that they won't have a meltdown. However, those who upgrade to an ATX 3.0 power supply should use the 12VHPWR cable to get all the benefits, including GPU communication through the data pins.

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TechSavy101

Posts: 15   +18
So what do we need a nuclear power plant to power up an Intel cpu with Nvidia graphics? 400+ Watt cpu and 600+ Watt gpu. AMD are only ones that think power efficiency is important too. Not to forget the big elephant in the room which is the price of 4090 that is ridiculous.
 

kiwigraeme

Posts: 1,315   +965
As a youtuber said if you run the 4090 on lesser cables and the data cable is not there - the 4090 will try to pull full power 450w with transient spikes way above that .
If you run on lesser cables , with proper data comm. yes the GPU may work but only say at 300w - so you wasted your money .
Depending how NVidia worded this - and what happens in the real world - it may be opening itself up to a class action .

Seriously who would run a RTX-4090 on a 850w PSU - I'm pretty sure 95% of the TS readers would not - add in a hot AMD/Intel - do you really want flakey power going to your drives etc .
How much heat would 850w PSU also generate running a 7950x or 13900 - sitting in your room n summer that's 37C or 100F

Add in more dust bunny maintenance - add in running big 48" monitor on same plug and speakers , woofers to boot . Imagine living in some tiny unconditioned room in a hot country . You will need to build a wall vent.

Add some countries do brownouts - ie drop voltage when under peak demand .

All I saying if you want a hot chip and 4090 do your homework and don't cheap out - top case , PSU at least 1000W - extra wall plug from fuse box if needed,
 

VitalyT

Posts: 6,413   +7,230
Jensen Huang is always like Alfred Bester from B5, always in black jacket.

He must be a P12, trying to reprogram us into believing RTX4090 can work off a solar panel.

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brucek

Posts: 1,297   +1,926
55 amps!!!

Per home electrical dot com: "The standard for most household circuits are rated either 15 amps or 20 amps. An important note to remember is that circuit breakers can only handle about 80% of their overall amperage. That means a 15-amp circuit breaker can handle around 12-amps and a 20-amp circuit breaker can handle about 16 amps."
 

Myflag

Posts: 13   +24
55 amps!!!

Per home electrical dot com: "The standard for most household circuits are rated either 15 amps or 20 amps. An important note to remember is that circuit breakers can only handle about 80% of their overall amperage. That means a 15-amp circuit breaker can handle around 12-amps and a 20-amp circuit breaker can handle about 16 amps."
It is not the same thing. That is 50 amps at 12 volts which is 600 watts. Your house power is likely 15 amps at 120 volts which is 1,800 watts.
 

Lounds

Posts: 1,225   +1,132
It is not the same thing. That is 50 amps at 12 volts which is 600 watts. Your house power is likely 15 amps at 120 volts which is 1,800 watts.
Wow US power sockets are weak AF. In the UK we can pull 3Kw from the wall. 13amp 240v.
 

Geralt

Posts: 1,308   +2,105
850W for the 4090 is a lie except your PC is completely Spartan. 1000W would be more realistic. To have your PSU so on the limit is not a good thing. And meltdown with adapters? They're crazy. The heat being generated is insane.
 

neeyik

Posts: 2,281   +2,759
Staff member
For reference, Nvidia state the following card power and PSU requirements for these cards:

3090 Ti - 450W / 850W
3090 - 350W / 750W
3080 Ti - 350W / 750W
3080 (12GB) - 320W / 750W
3080 (10GB) - 300W / 750W
2080 Ti - 260W / 650W
2080 Super - 250W / 650W
2080 - 225W / 650W

So if you already have a 3090 Ti in your system, and it all works fine, it’ll cope with a reference 4090 just as well.
 

DSirius

Posts: 368   +773
TechSpot Elite
For reference, Nvidia state the following card power and PSU requirements for these cards:

3090 Ti - 450W / 850W
3090 - 350W / 750W
3080 Ti - 350W / 750W
3080 (12GB) - 320W / 750W
3080 (10GB) - 300W / 750W
2080 Ti - 260W / 650W
2080 Super - 250W / 650W
2080 - 225W / 650W

So if you already have a 3090 Ti in your system, and it all works fine, it’ll cope with a reference 4090 just as well.
I think that only those with custom overclocked 4090 cards from AIB have to get the new ATX3.0 PSU with 16pin power cable.
 
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shark975

Posts: 101   +119
I remember online ppl used to make such a huge deal over power when amd cards were markedly less efficient. like it was all they talked about, how efficient nvidia was. now that nvidia cards are just blowing the roof off any previous power usage, nobody says a peep
 

Neatfeatguy

Posts: 1,026   +1,889
"An Nvidia FAQ rebutted the warning saying that while the concerns are legitimate, the adapters should not affect its new cards."

Should not - that's not very reassuring. It makes it sound like they still ran into some issues at a very small level, but they feel the few issues and loss of revenue is small enough to not worry about it.

Like a car manufacturer: (as some of you may remember from the movie Fight Club) "Now, should we initiate a recall? Take the number of vehicles in the field, A, multiply by the probable rate of failure, B, multiply by the average out-of-court settlement, C. A times B times C equals X. If X is less than the cost of a recall, we don't do one."
 

Nobina

Posts: 3,969   +4,560
Good thing I'm not mentally ill enough to warrant spending crazy amounts of money for a toy that also needs a new PSU to run. I hate how much I spent on my current hardware as it is but at least I'm satisfied with it.
 

DSirius

Posts: 368   +773
TechSpot Elite
I remember online ppl used to make such a huge deal over power when amd cards were markedly less efficient. like it was all they talked about, how efficient nvidia was. now that nvidia cards are just blowing the roof off any previous power usage, nobody says a peep
Indeed, and Karma bite Nvidia back quite fast.
 

captaincranky

Posts: 19,180   +8,328
Wow US power sockets are weak AF. In the UK we can pull 3Kw from the wall. 13amp 240v.
I have also heard that Europe has a higher electrocution death rate per capita with their 240 volt systems, than does the US running at 120 volts.

Feel free to research that, and rebut that if necassary. It's become too hard for me to post here because of account access and reliability issues, to waste additional time, "lookin' stuff up".

Oh BTW: 240 volts @ 15+ amps is readily available in the US. We use it all the time for washers, dryers, air conditioners, and more.

The 120 volt lines are only half wave AC. To get full wave 240 volts, you simply wire across 2 hot wires, instead of of 1 hot and a common.
 

captaincranky

Posts: 19,180   +8,328
Add in more dust bunny maintenance - add in running big 48" monitor on same plug and speakers , woofers to boot . Imagine living in some tiny unconditioned room in a hot country . You will need to build a wall vent.
A person in those circumstances should probably be doing more with their lives, than sitting in a one room tenement, playing video games on a $4,000.00+ computer. (Or their parent's basement).
 

bexwhitt

Posts: 614   +346
I have also heard that Europe has a higher electrocution death rate per capita with their 240 volt systems, than does the US running at 120 volts.

Feel free to research that, and rebut that if necassary. It's become too hard for me to post here because of account access and reliability issues, to waste additional time, "lookin' stuff up".

Oh BTW: 240 volts @ 15+ amps is readily available in the US. We use it all the time for washers, dryers, air conditioners, and more.so 120v

The 120 volt lines are only half wave AC. To get full wave 240 volts, you simply wire across 2 hot wires, instead of of 1 hot and a common.

all new installations in the UK have to have an RCD (GFCI) on all circuits now.Also 120v 15A is more than enough to kill someone.
 

captaincranky

Posts: 19,180   +8,328
all new installations in the UK have to have an RCD (GFCI) on all circuits now.
Yeah, we have a ground fault interrupters as a requirement for new construction as well. I think once upon a time it was only required near water.(kitchen and bathrooms)
Also 120v 15A is more than enough to kill someone.
True, but with some caveats. 240 volts gets you closer to the "no let go" threshold than does 120 volts. So, it's easier to kill yourself with 240 volts. But, with determination, (wet hands, standing in water, bare hot wire), 120 will granted, do the trick.

Fun fact: The tiny paddles used to start or stop the heart during surgery deliver current only on the order of a few milliamps. There you're working under the skin, in wet conditions, and directly in contact with the heart muscles. On dry skin. un-grounded, the no let go current threshold increases dramatically.

Funny story: My daddy was a TV repairman, from time to time, bringing home store record demonstration amplifiers. These were tube amps, (6V6 in push-pull), @ about 12 watts. By the time I got them, the PSU electrolytics had long since dried up and failed. Since these were proprietary parts, it was necessary to find caps of the same values, and tape them together as a pack.

So, I was doing this, save for the fact I forgot to connect them to the amp's (grounded) output transformer. Well, I got knocked on my a** about three times, before I figured out what was going on. The voltage at the caps was at least 400 volts, but with insufficient current and duration to kill me.

So, when you see those warnings about "lethal voltages inside", they should be taken with a grain of salt. f that doesn't work, crack out the defibrillator. CLEAR....:eek:
 

PEnnn

Posts: 957   +1,253
Wow US power sockets are weak AF. In the UK we can pull 3Kw from the wall. 13amp 240v.

Having lived in Europe and the US, I can say this: Compared to Europe, most US building standards (or any safety standards) are as good as any 5th World Country! Aka non existent or pathetically weak.

It took a MAJOR hurricane 25 years ago, that ravaged Florida and destroyed 1000s of homes because there was no building standard for houses to have the roof ATTACHED / secured to the house!!!

In the US, it takes a major, really fatal and expensive event for crooked US politicians to move their collective butts and pass a law about standards.....because having decent standards that save lives is "too cumbersome and costly for Big Business"!!

Hurricane Irma, 5 years ago: Hundreds of elderly residents (in buildings for the elderly) died from heat strokes in Florida - when those houses (owned by private companies who get tons of tax breaks) lost power and had no power generators.

Result? The US politicos woke up from their stupor and finally passed a law to compel those buildings to have power generators...but gave them 7 years to comply....yeah, too cumbersome to have it done in a year or so!!
 
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Bobbydpue

Posts: 394   +263
So what do we need a nuclear power plant to power up an Intel cpu with Nvidia graphics? 400+ Watt cpu and 600+ Watt gpu. AMD are only ones that think power efficiency is important too. Not to forget the big elephant in the room which is the price of 4090 that is ridiculous.
AMD doesn't use power in their TDP calculations. What specific real world use case would max out both your CPU and GPU at the same time?
 

waclark

Posts: 707   +451
Having lived in Europe and the US, I can say this: Compared to Europe, most US building standards (or any safety standards) are as good as any 5th World Country! Aka non existent or pathetically weak.

It took a MAJOR hurricane 25 years ago, that ravaged Florida and destroyed 1000s of homes because there was no building standard for houses to have the roof ATTACHED / secured to the house!!!

In the US, it takes a major, really fatal and expensive event for crooked US politicians to move their collective butts and pass a law about standards.....because having decent standards that save lives is "too cumbersome and costly for Big Business"!!

Hurricane Irma, 5 years ago: Hundreds of elderly residents (in buildings for the elderly) died from heat strokes in Florida - when those houses (owned by private companies who get tons of tax breaks) lost power and had no power generators.

Result? The US politicos woke up from their stupor and finally passed a law to compel those buildings to have power generators...but gave them 7 years to comply....yeah, too cumbersome to have it done in a year or so!!
Here's why that sounds like a great idea, but is flawed. OK, great, your generator is running. But, if the hurricane was bad enough it would likely take out your AC unit as well. So, did they mandate redundant AC units? Oh, and if you put that genny on the ground floor, it was likely taken out by the flooding. Just ask the folks in New Orleans. Also make sure you have enough fuel. They learned that up in WA State one year where an ice storm took out power for over a week. An AT&T data center only had about 3 days of propane to run the generator. Now they have larger tanks.