Question How much Watt (PSU) do I need for this build?

[rbogomolec]

My PSU died today. It was a 850W PSU from Seasonic. I got a 850W one cuz that's what everybody recommended me. But it turned out to be an overkill. I have a i5 9400f which ran at 30W maximum and a RX 6800 XT 16 GB which never got past 220W maximum while I was gaming even demanding open world games in 4k. Probably cuz I undervolted both CPU and GPU and I always play 60fps and on high settings instead of ultra, so they don't need as much juice as they usually would. Been gaming different games for over a year, and CPU+GPU never ever went over 250W together. Other than that, I have 1 HDD and 2 SSD disks inside and no extra fans or coolers. I have no intention of buying a 850W PSU again and please don't tell me that sometimes "the wattage might spike without me noticing" cuz I've ran a lot of tests and benchmarks with this build and it never spiked over the above mentioned numbers. So, in this case, can I go with a 500W PSU? Or 650W?

 

[JohnBonhamsGhost]

the manufacturer printed required minimum for the RX 6800 XT varies from 700-850w depending on your specific model.

if you want to go below that number for your specific card then you will be dealing with the consequences like no boosting in games or other applications,
outright crashing when the power draw spikes, etc...

ran a lot of tests and benchmarks with this build and it never spiked over the above mentioned numbers

what exact sort of "wattage sensor" are you claiming that you use for this process that is located between the unit itself and the connected components to read their actual power draw?

a 850W PSU from Seasonic...
in this case, can I go with a 500W PSU? Or 650W?

hopefully you are also keeping in mind the actual quality of any unit in particular and not just some manufacturer and the stated wattage available.

 

[MrVendaval]

My PSU died today. It was a 850W PSU from Seasonic. I got a 850W one cuz that's what everybody recommended me. But it turned out to be an overkill. I have a i5 9400f which ran at 30W maximum and a RX 6800 XT 16 GB which never got past 220W maximum while I was gaming even demanding open world games in 4k. Probably cuz I undervolted both CPU and GPU and I always play 60fps and on high settings instead of ultra, so they don't need as much juice as they usually would. Been gaming different games for over a year, and CPU+GPU never ever went over 250W together. Other than that, I have 1 HDD and 2 SSD disks inside and no extra fans or coolers. I have no intention of buying a 850W PSU again and please don't tell me that sometimes "the wattage might spike without me noticing" cuz I've ran a lot of tests and benchmarks with this build and it never spiked over the above mentioned numbers. So, in this case, can I go with a 500W PSU? Or 650W?

From what I see, the 6800 XT can spike close to 450W. The fact that you've undervolted it and aren't pushing the card to 100% load seems to address this issue. No program will detect power draw spikes lasting just a few milliseconds. The power supply isn't the most expensive part of your setup, but it is crucial. If you have the option to spend an extra $25 on a better quality power supply, preferably an ATX 3.0, go for it. It’s worth the investment for system stability and longevity. I'd not go for less than 650W.

 

[DaleH]

My PSU died today. It was a 850W PSU from Seasonic. I got a 850W one cuz that's what everybody recommended me. But it turned out to be an overkill. I have a i5 9400f which ran at 30W maximum and a RX 6800 XT 16 GB which never got past 220W maximum while I was gaming even demanding open world games in 4k. Probably cuz I undervolted both CPU and GPU and I always play 60fps and on high settings instead of ultra, so they don't need as much juice as they usually would. Been gaming different games for over a year, and CPU+GPU never ever went over 250W together. Other than that, I have 1 HDD and 2 SSD disks inside and no extra fans or coolers. I have no intention of buying a 850W PSU again and please don't tell me that sometimes "the wattage might spike without me noticing" cuz I've ran a lot of tests and benchmarks with this build and it never spiked over the above mentioned numbers. So, in this case, can I go with a 500W PSU? Or 650W?

You can use this calculator: https://outervision.com/power-supply-calculator

 

[rbogomolec]

the manufacturer printed required minimum for the RX 6800 XT varies from 700-850w depending on your specific model.

if you want to go below that number for your specific card then you will be dealing with the consequences like no boosting in games or other applications,
outright crashing when the power draw spikes, etc...


what exact sort of "wattage sensor" are you claiming that you use for this process that is located between the unit itself and the connected components to read their actual power draw?


hopefully you are also keeping in mind the actual quality of any unit in particular and not just some manufacturer and the stated wattage available.

I use MS Afterburner to track my wattage. Sometimes I leave it on for the whole gaming session and I've never seen a number bigger that 220W no matter what was going on in any game. If you're implying that the GPU can suddenly peak from 220W to like 700W without Afterburner noticing it, then I see what you mean. Btw, I'm not being sarcastic. Is it really possible for the GPU to spike like that? Cuz if it is then I need a strong PSU again. If it isn't then I don't need it.

 

[MrVendaval]

I use MS Afterburner to track my wattage. Sometimes I leave it on for the whole gaming session and I've never seen a number bigger that 220W no matter what was going on in any game. If you're implying that the GPU can suddenly peak from 220W to like 700W without Afterburner noticing it, then I see what you mean. Btw, I'm not being sarcastic. Is it really possible for the GPU to spike like that? Cuz if it is then I need a strong PSU again. If it isn't then I don't need it.

I was working recently with a guy on a 7800XT, and we saw a 400W+ spike on it. Someone else posted about a 600W spike on a 7900XTX, so it's definitely a thing, especially if you overclock. Igorslab is the best source in my opinion:

 

[rbogomolec]

I was working recently with a guy on a 7800XT, and we saw a 400W+ spike on it. Someone else posted about a 600W spike on a 7900XTX, so it's definitely a thing, especially if you overclock. Igorslab is the best source in my opinion:

Oh, ok... Thanks man, I didn't know that! I'm actually slowly thinking about selling this whole damn thing and looking for another hobby. I've put over 1000€ (plus 800€ for a big 4k TV) into this box and it now it doesn't turn on anymore. I don't care if it's just the PSU, it' always gonna be "just something". Ruined my Saturday night and it'll ruin some more days as well to get the PC back fixed again.

 

[MrVendaval]

Electronics tend to bite the dust sometimes, nothing unusual. It doesn't always need a reason. Maybe it's a sign to try out a console for that 4K TV of yours? 😉

 

[rbogomolec]

Yup. Nothing runs Assassin's Creed: Black Flag like a PC

 

[JohnBonhamsGhost]

now it doesn't turn on anymore. I don't care if it's just the PSU, it' always gonna be "just something"

which specific Seasonic model unit did you have?
all manufacturers/distributors offer lower quality models that just cannot stand up to heavy usage like gaming.

while Seasonic does offer some very good, if not some of the best, units out there.
they also have some models that are just not reliable in these types of scenarios.

what is the warranty on your unit?
if it is a better model, then it will be at least ~8 years.
you should be able to get a replacement pretty easily if so.

 

[COLGeek]

For a couple of you, I need to remind you that Tom's Hardware does not support any form of software piracy. None. Period.

Any further discussion of such will result in sanctions.