850 watt enough for 7800x3d + 4090?

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Bigbacon

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Jul 12, 2007
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Curious. Looking at upgrading everything....

I have an evga 850 watt PSU new in the box sitting in my basement.

would it be enough for a 4090 and a 7800x3d?
 
I myself wouldn't chance it, but you might be okay. I'd go no lower than 1000W and either a platinum or titanium rated power supply.
 
Niner21 said:
I myself wouldn't chance it, but you might be okay. I'd go no lower than 1000W and either a platinum or titanium rated power supply.
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I go chancy on PSU a lot...I mean I never buy expensive ones. Hell the one I'm using right now is an old BFG 800 watt from like...2009 maybe? i mean a 5800x3d and 3080 doesn't use as much power but its lasted this long no problems :)
 
I wouldnt have concerns with a quality 850w and that setup. Too much money for that setup to be chincy on a psu. Also if you use your rig a lot and keep your psu's for a long time, then a platinum or higher psu may actually be cheaper over time via efficiency.
 
What was the point of this? If you're aiming to get "chancy" anyways, then why ask? You can easily just find the max TDP numbers of all the parts (or just dial them into PCPartpicker and it will add them up for you) and then do the math and see if it fits within the power envelope of your current "chancy" PSU. Alternatively, don't even bother with that. Just yolo swag throw it in for ultimate gambling, because heck most computers aren't actually going to be using their CPUs and GPUs going at full throttle basically ever, in real world use, right? You "probably" won't run into any issues, right? There's really no point in spending like less than 10% of how much you just spent on that CPU+GPU to upgrade to 1kW PSU that "definitely" won't have any issues, and will be reusable for several builds down the line... right?

... =\
 
What model is it exactly? There are a whole gamut of EVGA units out there in the 850w class from excellent to trash level.
 
hititnquitit said:
What model is it exactly? There are a whole gamut of EVGA units out there in the 850w class from excellent to trash level.
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210-GQ-0850-RX. Its probably many years old though, new in the box though.

StoleMyOwnCar said:
What was the point of this? If you're aiming to get "chancy" anyways, then why ask? You can easily just find the max TDP numbers of all the parts (or just dial them into PCPartpicker and it will add them up for you) and then do the math and see if it fits within the power envelope of your current "chancy" PSU. Alternatively, don't even bother with that. Just yolo swag throw it in for ultimate gambling, because heck most computers aren't actually going to be using their CPUs and GPUs going at full throttle basically ever, in real world use, right? You "probably" won't run into any issues, right? There's really no point in spending like less than 10% of how much you just spent on that CPU+GPU to upgrade to 1kW PSU that "definitely" won't have any issues, and will be reusable for several builds down the line... right?

... =\
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I didn't say I was going to use my "chancy" PSU...I just think that its often blown out of proportion of how well they work and handle things.
 
Bigbacon said:
210-GQ-0850-RX. Its probably many years old though, new in the box though.



I didn't say I was going to use my "chancy" PSU...I just think that its often blown out of proportion of how well they work and handle things.
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Thats a solid unit. Built by FSP. It's an older platform so it may or may not handle the transients of your 4090. It certainly wont kill anything if you try it out.
 
Bigbacon said:
210-GQ-0850-RX. Its probably many years old though, new in the box though.



I didn't say I was going to use my "chancy" PSU...I just think that its often blown out of proportion of how well they work and handle things.
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I'd just try it and see. Ideally 1000W is a good number just because these top dog cards from both brands can have very high transient spikes, but I think with a quality 850W from EVGA you'd be fine. I ran my 4090 on my friends 10700K machine with a Corsair 750W and it had no problem, he had a bad GPU so I moved mine over to test the rest of the system and it played games just fine.
 
As far as I can see, the PSU you listed is Tier B on the cultist list.

Bigbacon said:
I didn't say I was going to use my "chancy" PSU...I just think that its often blown out of proportion of how well they work and handle things.
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Some people speed in cars. Some people smoke cigars. They can do that for months, years, and maybe their whole lives... and have nothing bad happen. Are the dangers just overblown then? What happens if something does happen? Look at after-wreck pictures of speeders (well or their victims), or people hooked up to hospital equipment due to long term effects of smoking. I know, far from a perfect analogy.

Point is, you just spent about 2300+++ USD on a (excessively) top end GPU/CPU/Motherboard/etc. That's more than 1-2 mortgage payments. All of that will also probably be showing its age well within 5 years. You're being wishy washy about spending <<9-15% of that (depending on Gold or Platinum) on a nice 1-1.2kW PSU unit that you know won't have issues, to protect that investment (and possibly many other investments) long term, which will also last probably 10+ years, throughout multiple rebuilds?

I don't see the logic. The PSU is one of the most futureproof things you can buy. I still have a TX650 from like 15 years ago that's alive and kicking. My tone would be different if you didn't just buy a >1.6k USD graphics card. Like, you clearly have the money... well, do what you want I guess.
 
when I first got my 4090 I ran it on a 750 watt EVGA PSU with zero issues. I eventually upgraded to a seasonic vertex 1200 mainly to see if using a native 12vhpwr connector unlocked higher power limits (it didn’t) the only difference I noticed between the 750 and 1200 is less coil whine.
 
850W should be plenty. My UPS shows anywhere between 600W and 700W from the wall while gaming on the PC in my signature (570-665W output from the PSU at 95% efficiency). I just got a 1000W PSU to deal with the transient spikes on my old 3090. You do need to have 4 separate PCI-E cables if you're going to be using the power adapter for your 4090, though, so make sure whatever power supply you get supports that. You cannot use a single cable that splits into 2 plugs like some power supplies do.
 
StoleMyOwnCar said:
As far as I can see, the PSU you listed is Tier B on the cultist list.



Some people speed in cars. Some people smoke cigars. They can do that for months, years, and maybe their whole lives... and have nothing bad happen. Are the dangers just overblown then? What happens if something does happen? Look at after-wreck pictures of speeders (well or their victims), or people hooked up to hospital equipment due to long term effects of smoking. I know, far from a perfect analogy.

Point is, you just spent about 2300+++ USD on a (excessively) top end GPU/CPU/Motherboard/etc. That's more than 1-2 mortgage payments. All of that will also probably be showing its age well within 5 years. You're being wishy washy about spending <<9-15% of that (depending on Gold or Platinum) on a nice 1-1.2kW PSU unit that you know won't have issues, to protect that investment (and possibly many other investments) long term, which will also last probably 10+ years, throughout multiple rebuilds?

I don't see the logic. The PSU is one of the most futureproof things you can buy. I still have a TX650 from like 15 years ago that's alive and kicking. My tone would be different if you didn't just buy a >1.6k USD graphics card. Like, you clearly have the money... well, do what you want I guess.
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The logic is, is it necessary? You can buy a million Dollar home or more that doesn’t mean you need a $10,000 cutlery set. My 4090 under cpu limited scenarios uses less power than my 3080 did and in more GPU intensive games, just marginally more.

if You’re running a gigabyte PSU that explodes when overloaded, by all means replace it. But virtually every other decent brand will simply shut down, which is highly unlikely with an 850 watter and a 4090 as you have about 150-200 watts of slack.
 
WilyKit said:
The logic is, is it necessary? You can buy a million Dollar home or more that doesn’t mean you need a $10,000 cutlery set. My 4090 under cpu limited scenarios uses less power than my 3080 did and in more GPU intensive games, just marginally more.
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That's completely faulty logic and a horrible analogy, even for most analogy standards. A $10,000 cutlery, or any cutlery set, is nothing but luxury. It doesn't functionally impact your manor in any way unless you hired a professional cook that could properly utilize said cutlery to prepare food faster. Your mansion doesn't have any chance of randomly burning down or being destroyed by said cutlery, and is fundamentally unaffected by whether you buy it or not.

A slightly more apt analogy would be getting a large property/estate that doesn't closely border any trees and hence deciding to forego termite treatment that would cost you $10,000... because chances are it won't happen. Except that's still not quite accurate. The PSU is feeding your computer energy every single second it's on. It's basically the foundation of your computer's (and many computers you will create thereafter) continued operation. Do you want a good foundation or a bad one?
 
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Whoa, slow down guys.

The PSU the OP is pondering isn't some pos off the scrap heap. It's perfectly fine for the components he has configured. It's not going to explode or take out his GPU. At worst it may cause a crash while gaming.
 
StoleMyOwnCar said:
That's completely faulty logic and a horrible analogy, even for most analogy standards. A $10,000 cutlery, or any cutlery set, is nothing but luxury. It doesn't functionally impact your manor in any way unless you hired a professional cook that could properly utilize said cutlery to prepare food faster. Your mansion doesn't have any chance of randomly burning down or being destroyed by said cutlery, and is fundamentally unaffected by whether you buy it or not.

A slightly more apt analogy would be getting a large property/estate that doesn't closely border any trees and hence deciding to forego termite treatment that would cost you $10,000... because chances are it won't happen. Except that's still not quite accurate. The PSU is feeding your computer energy every single second it's on. It's basically the foundation of your computer's (and many computers you will create thereafter) continued operation. Do you want a good foundation or a bad one?
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Upgrading a PSU that doesn’t need to be upgraded is a luxury expense. Analogy works.

I guess you also go through your home and I graded all your electrical to 0 gauge wiring for your 15 amp circuits? I mean they are feeding your devices 24/7 right?
 
WilyKit said:
Upgrading a PSU that doesn’t need to be upgraded is a luxury expense. Analogy works.

I guess you also go through your home and I graded all your electrical to 0 gauge wiring for your 15 amp circuits? I mean they are feeding your devices 24/7 right?
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No it doesn't work. It's full of a lot of holes, but your second line is exactly the main point. Power supplies have to deal with a lot of shit from your street voltage and house wiring (and fixing that can be expensive, as you're clearly alluding whether you realize it or not). When they do power supply reviews (or they used to last I looked), a lot of what would go into the rating is how clean and consistent the power delivery to the component is and other such factors. You're suggesting that powering over $2400 of equipment... on a unit that's ranked B (not A) on a much-cited ranking list... and is going to basically be pushed near the cusp of its maximum power draw in worst case scenarios... is a good idea, and as such is just totally unnecessary to upgrade? We clearly won't agree on this. I personally think it's asinine to put something this expensive on anything but a very highly rated unit, considering the amount of extra money spent on it would be nothing compared to the setup, and year over year might even pay for itself depending on efficiency gains.
 
StoleMyOwnCar said:
No it doesn't work. It's full of a lot of holes, but your second line is exactly the main point. Power supplies have to deal with a lot of shit from your street voltage and house wiring (and fixing that can be expensive, as you're clearly alluding whether you realize it or not). When they do power supply reviews (or they used to last I looked), a lot of what would go into the rating is how clean and consistent the power delivery to the component is and other such factors. You're suggesting that powering over $2400 of equipment... on a unit that's ranked B (not A) on a much-cited ranking list... and is going to basically be pushed near the cusp of its maximum power draw in worst case scenarios... is a good idea, and as such is just totally unnecessary to upgrade? We clearly won't agree on this. I personally think it's asinine to put something this expensive on anything but a very highly rated unit, considering the amount of extra money spent on it would be nothing compared to the setup, and year over year might even pay for itself depending on efficiency gains.
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maybe you need to read more reviews. Quality PSU are able to maintain their rated output with a wide variety of input voltage and noise.

Looking forward to your next long winded rant.
 
WilyKit said:
maybe you need to read more reviews. Quality PSU are able to maintain their rated output with a wide variety of input voltage and noise.

Looking forward to your next long winded rant.
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I like how you're literally arguing against yourself with that statement, because that was exactly a large portion of my point. Well whatever, since you're just trolling at this point, here's your long winded rant: blocked. Bye.
 
StoleMyOwnCar said:
I like how you're literally arguing against yourself with that statement, because that was exactly a large portion of my point. Well whatever, since you're just trolling at this point, here's your long winded rant: blocked. Bye.
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Sound like someone who thinks there’s more than two genders
 
From what I've noticed is that it's a lot more common that people spend more than they need in regards to PSU. Then when it's their next big upgrade, they're going to buy a new PSU again anyways, because they're more comfortable spending money (as we've already learned). Horror stories of builds blowing up due to an insufficient or off-brand PSU's are just that - horror stories. The absolute worst thing that could happen is...*gasp* you might have to send back the PSU for a higher wattage. Having said that, you're better off with less wattage from a reputable brand than 850W from JoeSmoPower.
 
I have an OCZ Gold 850w circa 2011? I'll have to double check the part number exactly but would be nice to know who actually made it.
 
Every single EVGA 850w unit i can find runs that single +12v rail at ~70.8a.

The 4090 has an official draw of ~450w which is in the area of 37-38a.

OP is fine and ya'll know it. Beef more :hungry: :D
 
FWIW I was getting dangerously close to hitting my 850W PSU limit with my 5950X + 3080 (With 3x power connectors) but I also have 12 HDDs, which can theoretically add another 100w or so of power usage.
230W CPU, 420W GPU, 100~W HDDs left 100W for all the fans, pump, rgb, peripherals, etc. I'm also a use case where I do hit 100% load on GPU and CPU simultaneously. Though hitting every HDD at load simultaneously was unlikely, transient power spikes and weird, one-off loads put me over 850w a few times. (I have since upgraded to a 1200W platinum PSU)
 
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