what wattage do i need to upgrade my gpu?

[N37F]

I am building a pc and bought all parts on black Friday except the GPU, was waiting for a GPU to release,and the rx7900 xtx is coming soon

partpicker estimated wattage without a GPU is 321

And AMD recommends at least an 850w PSU

And I have a 750w PSU

And the rx7900xtx uses about 335w so 656w in total will I be fine or do I need to buy a new psu? I have about 100w wiggle room i see that as more then enough but i am no expert

https://pcpartpicker.com/list/FsQHjZ

[adm0n]

Your calculation is sound. But until anyone tries it out, you don't know if those cards have short power consumption spikes, that go well above the 335W power target.

The 3000 series was notorious for these "transient spikes".

 

I also suspect, that the recommended PSU figure they give is calculated as: GPU Wattage + the most power hungry setup any reasonable person could ever have".
Just so that they don't have to deal with the bad press, that peoples computers blackscreen all the time.

[PDifolco]

It'll be fine if you have a good PSU, if it's a crap one it may fail on occasional spikes

What's the brand/model ?

[Takumidesh]

are you including drives, USB devices (like headphones, mouse/keyboard, microphone, controllers), fans, or anything else powered off of the power supply?

 

5 or 6 fans, a couple drives, and a bunch of various usb stuff, might not quite get up to 100W but it may be close.

 

The motherboard itself can potentially draw up to 50-60 watts.

4 sticks of ram can pull ~10-15W.
 

 

It all depends on what you are including in these counts.

If you want to see the true power usage, use a kill-a-watt or something similar. there are inefficiencies, but you can look up the inefficiency of the power supply to offset the reading from the wall.

[mariushm]

Motherboard is more like 10-15 watts. Ram is around 2-3 watts per stick. Fans usually consume under 2-3 watts.

USB stuff by design should be under 5 watts for each usb 3.0 port (5v at 0.9a limit) , unless they're full of leds a mouse and a keyboard usually consume under 1w

CPU will consume a lot of power only when running at 100% - not all games will us all cores at 100% ... the estimations will use the peak power as if you run 100% cpu usage.

Video card is unlikely to peak at more than 350 watts.

 

If it's a decent 750w psu, you'll be fine.

 

[N37F]

20 minutes ago, PDifolco said:

It'll be fine if you have a good PSU, if it's a crap one it may fail on occasional spikes

What's the brand/model ?

Msi mpg a750gf

[Crunchy Dragon]

Personally, with how power hungry modern components are, I have an extremely hard time recommending anything PSU lower than 850W.

 

As for myself, I don't buy PSUs lower than 1000W if I want the system to last as long as possible. Your PSU and case should be the parts of your PC that you change the least frequently.

[Skiiwee29]

20 minutes ago, Crunchy Dragon said:

Personally, with how power hungry modern components are, I have an extremely hard time recommending anything PSU lower than 850W.

 

As for myself, I don't buy PSUs lower than 1000W if I want the system to last as long as possible. Your PSU and case should be the parts of your PC that you change the least frequently.

Agreed. This is why I upgraded to an HX1200 for my current system. My system was triggering OCP on an HX850 due to the transient spikes.

[PDifolco]

3 hours ago, N37F said:

Msi mpg a750gf

Yeah it's a good PSU, should be good and worse that can happen is OCP shutdown, then you'll know you have to replace it if it happens