Question Questions about PSU choice for i5-9400f + RX 6800 XT ?

[rbogomolec]

Currently I'm running a 500W PSU. Please don't ask me which exactly, my PC case is kinda hard to open and I can't get in. I've always been a noob with handling PC hardware... Anyway, I've got an i5-9400f (uses 65-95W peak) and I've recently bought a Sapphire RX 6800 XT Nitro+ (peak around 300W according to the Internet, with no OC). Other than that I've got 16GB RAM, 256GB SSD, 1TB HDD (I don't know how much power they consume, but probably not much, right?). Before I replace my existing GPU with the RX 6800 XT, I'd like to ask you guys some stuff regarding power consumption.

1. From the information I gave you, can you guess how many watts I'll need? I don't plan to OC neither my CPU nor my GPU. The only thing I'm gonna do is undervolt both of them. Btw, on the GPU box it says minimum 850W PSU required, but I know that that's way too much for this rig. I've seen some benchmarks of this exact GPU on YouTube (+ some CPU that draws more power than mine according to it's specs) and the guy ran the whole system at some 530W while playing some AAA games on high settings and 4k resolution. So I should probably go with 600W, or even 550W, right?

2. Does undervolting your components actually decrease you overall Watt consumption? If so, is there a formula to calculate how much? Let's say I undervolt my CPU for -60mV and my GPU for -80mV, how much would the overall Watt consumption drop?

3. Is it true that the CPU doesn't work harder regardless of the gaming resolution? I'm gaming at 2k at the moment cuz my old GPU can't handle 4k. My CPU power consumption is at, let's say, average 55W and temps at average 55'C while gaming. Once I get my new GPU installed and start gaming at 4k, can I expect my CPU to start consuming visibly more power and get hotter (like 65W and 65'C for example) or is all the "extra resolution" load really going to the GPU and the CPU is just doing the same work he did at 2k?

4. What do you think about Red Dragon PSU? 600W modular. I read on forums that people write stuff like "stay away", but when I watch YouTube videos the comments and reviews are way better. Also, how much more would a "better" PSU cost? Is the difference around 20 Euro, or more like 50+ Euro?

 

[dark_globe]

1.+2.+3. :
your entire system will draw around 400-450w of power while gaming
(even less so if you undervolt your gpu but i see no reason why because you also
may run into instability issues if undervolting too much and
you may have to lower clock speeds = not the best performance ,
keep in mind your cpu will already hinder 6800xt in some games to a decent degree) .

your cpu even while stressed to the max. level in prime95 does not draw more than 150w
(at typical gaming load it will be far less)
and the 6800xt is around 270-300w at typical gaming load ,
rest of the system is 30-50w at best .
that being said you always want to have some breathing room for your power supply -
power supplies are performing to their best while at 40-60% load and they also last more years .
(they are also more quiet and run cooler)
ideally for this system you want to have 750w good quality power supply .

your cpu would be even worse (more of a bottleneck) at 1080p
2K is more taxing for your graphics card (but it doesn´t mean it will draw more power)
so your cpus shortcomings will be less wisible compared to 1080p
but they will still be there because it´s an old six core with relatively low boost clocks
you will see your cpu run at 95-100% in some modern games and your graphics
will be underperforming in some of them due to cpu limitations ,
so you may not see your graphics card run at 80-100% every time even at 2K .
(in games that are more cpu than gpu bound you will experience stuttering and fps drops sometimes)

4. DON´T SKIMP ON YOUR POWER SUPPLY -
no name units often can´t deliver their rated power ,
or can´t maintain stable heavy load for prolonged gaming sessions
(your pc may turn of while in the middle of the game for example)
and they are dangerous for your other components
if they die they often don´t have properly funcioning protections and
may fry your motherboard or graphics card on their way out .
buy good quality 750w gold rated unit from reputable brand :
to name a few: adata core reactor , corsair RMx series ,
phanteks AMP , MSI A GF series , asus strix series , seasonic focus -
those are all good quality units .
avoid "dragons" , "diesels" , "devils" etc .

 

[rbogomolec]

Thanks man! Good info! So what do you think of Seasonic 650W G12 GC 650, 80 PLUS Gold, G12-GC-650? Btw, I know it's 650W but I'm 100% sure it'll be enough power-wise.

 

[rbogomolec]

1.+2.+3. :
your entire system will draw around 400-450w of power while gaming
(even less so if you undervolt your gpu but i see no reason why because you also
may run into instability issues if undervolting too much and
you may have to lower clock speeds = not the best performance ,
keep in mind your cpu will already hinder 6800xt in some games to a decent degree) .

your cpu even while stressed to the max. level in prime95 does not draw more than 150w
(at typical gaming load it will be far less)
and the 6800xt is around 270-300w at typical gaming load ,
rest of the system is 30-50w at best .
that being said you always want to have some breathing room for your power supply -
power supplies are performing to their best while at 40-60% load and they also last more years .
(they are also more quiet and run cooler)
ideally for this system you want to have 750w good quality power supply .

your cpu would be even worse (more of a bottleneck) at 1080p
2K is more taxing for your graphics card (but it doesn´t mean it will draw more power)
so your cpus shortcomings will be less wisible compared to 1080p
but they will still be there because it´s an old six core with relatively low boost clocks
you will see your cpu run at 95-100% in some modern games and your graphics
will be underperforming in some of them due to cpu limitations ,
so you may not see your graphics card run at 80-100% every time even at 2K .
(in games that are more cpu than gpu bound you will experience stuttering and fps drops sometimes)

4. DON´T SKIMP ON YOUR POWER SUPPLY -
no name units often can´t deliver their rated power ,
or can´t maintain stable heavy load for prolonged gaming sessions
(your pc may turn of while in the middle of the game for example)
and they are dangerous for your other components
if they die they often don´t have properly funcioning protections and
may fry your motherboard or graphics card on their way out .
buy good quality 750w gold rated unit from reputable brand :
to name a few: adata core reactor , corsair RMx series ,
phanteks AMP , MSI A GF series , asus strix series , seasonic focus -
those are all good quality units .
avoid "dragons" , "diesels" , "devils" etc .

Ok forget the one I wrote first, I read it's made by Helly. This one should be an original though. Getting good reviews as well. Seasonic 650W B12-BC-650

 

[geofelt]

1. Here is a general guideline as to the power required for graphics cards:

PSU REQUIREMENTS - RealHardTechX

PSU REQUIREMENTS - RealHardTechX

www.realhardtechx.com

6800XT shows 700w.
If your card is a factory overclocked version requiring more than two 8 pin connections, the power required will be more.
Modern graphics cards can have very high power spikes. If the psu can't handle them, your game fails.
For that reason, it is recommended that one buy a quite strong psu.
Do not worry, it will only use the power demanded of it, regardless of the max capability. And, a psu operating in the middle third of the range will be more efficient and quieter.
You will also find that stepping up in power costs only a small incremental price.
For example, the seasonic Focus GX850 with a 10 year warranty costs only $20 more than 750W and the 1000w unit is $40 more.
Likely, the corsair RMx units have a similar pricing structure.

2. Undervolting serves no useful purpose, and in doing so you may screw things up. Any electrical cost savings will be minor. In a similar vein, platinum rating vs. gold rating does not confer much savings.

3. If you improve graphics, that is currently a limiter, then you can expect the cpu to work harder. Try this simple test:
Run YOUR games, but lower your resolution and eye candy.
This makes the graphics card loaf a bit.
If your FPS increases, it indicates that your cpu is strong enough to drive a better graphics configuration.
If your FPS stays the same, you are likely more cpu limited.
I might think that considering the disparity in capability of the cpu vs. processor, you are likely to be more cpu limited.

4. As an estimate of psu quality, the warranty is, I think most telling.
7 years or more gets you a good quality psu.
A cursory look shows that red dragon has a 2 year warranty.

 

[rbogomolec]

1. Here is a general guideline as to the power required for graphics cards:

PSU REQUIREMENTS - RealHardTechX

PSU REQUIREMENTS - RealHardTechX

www.realhardtechx.com

6800XT shows 700w.
If your card is a factory overclocked version requiring more than two 8 pin connections, the power required will be more.
Modern graphics cards can have very high power spikes. If the psu can't handle them, your game fails.
For that reason, it is recommended that one buy a quite strong psu.
Do not worry, it will only use the power demanded of it, regardless of the max capability. And, a psu operating in the middle third of the range will be more efficient and quieter.
You will also find that stepping up in power costs only a small incremental price.
For example, the seasonic Focus GX850 with a 10 year warranty costs only $20 more than 750W and the 1000w unit is $40 more.
Likely, the corsair RMx units have a similar pricing structure.

2. Undervolting serves no useful purpose, and in doing so you may screw things up. Any electrical cost savings will be minor. In a similar vein, platinum rating vs. gold rating does not confer much savings.

3. If you improve graphics, that is currently a limiter, then you can expect the cpu to work harder. Try this simple test:
Run YOUR games, but lower your resolution and eye candy.
This makes the graphics card loaf a bit.
If your FPS increases, it indicates that your cpu is strong enough to drive a better graphics configuration.
If your FPS stays the same, you are likely more cpu limited.
I might think that considering the disparity in capability of the cpu vs. processor, you are likely to be more cpu limited.

4. As an estimate of psu quality, the warranty is, I think most telling.
7 years or more gets you a good quality psu.
A cursory look shows that red dragon has a 2 year warranty.

Exactly what you've said. I found a Seasonic 750W B12-BC-750 for just 20€ more than the Seasonic 650W B12-BC-650. So I went with it. It also has the 80+ bronze, so I should be safe.

I'm not an "ultra settings" gamer so it should be fine. I just don't want my games to be blurry on a 65" 4k tv, that's all. So I'll play at 4k, high setting with some demanding stuff that I don't need (like shadows) at medium settings. As far as I've seen, the 6800 XT can handle that without going all-out on power consumption.

One more thing that bugs me though... Everyone is talking about an i5 9400f being a bottleneck to the 6800 RX, especially at 1080p. I don't really understand that, but I have a feeling that we're talking strictly about FPS here. Am I right? Cuz if so, it's no problem for me. I'm a 60fps solo gamer who plays rpg-s, adventure games and some occasional Resident Evil game. No multiplayer shooters or stuff like Dota. So if bottleneck means what I think it means, I won't even notice it with my 60fps cap, right?

 

[DSzymborski]

The B12 is made by Helly Tech, too, unless I'm mistake. Bronze isn't a "to be safe" certification; you really have to generally cheap out these days compared to good PSUs to *only* get a Bronze rating.

You keep talking about reviews, but there are only a few sites that do reputable reviews; if the review doesn't include a load tester, an oscilloscope, and a detailed component analysis (or at least images), it's not really a review. SeaSonic has not been very aggressive at sending out products for review when they outsource the manufacture, and I have a fairly good idea why.

 

[DSzymborski]

Let's see what capacitors they used for this...oh.

Oh, look, AsiaX.

🤮

In all seriousness, this ought to be fine on a budget gaming build. To see this on an RX 6800 XT build, however, is quite underwhelming. "At least the fourth tier, cheap Chinese capacitors are 105 degrees instead of 85!" isn't a phrase that should be associated with a PC build of this quality.

 

[rbogomolec]

Let's see what capacitors they used for this...oh.

Oh, look, AsiaX.

🤮

In all seriousness, this ought to be fine on a budget gaming build. To see this on an RX 6800 XT build, however, is quite underwhelming. "At least the fourth tier, cheap Chinese capacitors are 105 degrees instead of 85!" isn't a phrase that should be associated with a PC build of this quality.

It's these kind of comments that always confuse me. I know that this can't be as good as a 200-300€ PSU, but I do hope it's ok. Cuz ok is enough for me. Right now, I'm playing 2k medium/high settings 60fps Sekiro on a cheap no-name PSU and I never had problems though my 1660 and the i5 9400f are working almost full load almost always. I'm sure people would call it crap, but it works just fine. No 80 Plus, no nothing. But after reading your comment I'm afraid that I've payed 100€ for something that'll burn my pc or won't get it even started.
As for my rig, I don't consider it high end. I grabbed the 6800 XT cuz it was just 80€ more than the RTX 3060. But my cpu is i5 9400f and I intend to play 4k, 60fps, medium/high settings, nothing more. If I wanted ultra 120fps, then I wouldn't go for a 100€ PSU ofc, and would upgrade my cpu as well. I did find reviews and YouTube videos and comments on this one an people siad it's ok. Not great, but not crap either. Just the level that I'm looking for. But then I see someone who obviously knows more than me, like you, and you call it crap. Now I can't make out if your standards are too high, or mine just too low. I'm not sure if you're saying this just cuz you think that "a 6800 XT deserves a better rig" or literally cuz this PSU is not gonna meet the power demands of my mediocre/slightly-high gaming settings and I'll have to buy one for 200+€ in the end.
And don't get me wrong. I don't mean no disrespect to you and I'm not here to argue. I'm literally just confused now after reading your quite well argumented reply. Is there danger of damaging the PC, or can I expect higher cpu/gpu temperatures, or something like that?
Again, sorry if sound like I'm arguing, I'm not. I literally have 0 knowledge about PSU quality and didn't even know that it's a thing. 😓

 

[DSzymborski]

It's these kind of comments that always confuse me. I know that this can't be as good as a 200-300€ PSU, but I do hope it's ok. Cuz ok is enough for me. Right now, I'm playing 2k medium/high settings 60fps Sekiro on a cheap no-name PSU and I never had problems though my 1660 and the i5 9400f are working almost full load almost always. I'm sure people would call it crap, but it works just fine. No 80 Plus, no nothing. But after reading your comment I'm afraid that I've payed 100€ for something that'll burn my pc or won't get it even started.
As for my rig, I don't consider it high end. I grabbed the 6800 XT cuz it was just 80€ more than the RTX 3060. But my cpu is i5 9400f and I intend to play 4k, 60fps, medium/high settings, nothing more. If I wanted ultra 120fps, then I wouldn't go for a 100€ PSU ofc, and would upgrade my cpu as well. I did find reviews and YouTube videos and comments on this one an people siad it's ok. Not great, but not crap either. Just the level that I'm looking for. But then I see someone who obviously knows more than me, like you, and you call it crap. Now I can't make out if your standards are too high, or mine just too low. I'm not sure if you're saying this just cuz you think that "a 6800 XT deserves a better rig" or literally cuz this PSU is not gonna meet the power demands of my mediocre/slightly-high gaming settings and I'll have to buy one for 200+€ in the end.
And don't get me wrong. I don't mean no disrespect to you and I'm not here to argue. I'm literally just confused now after reading your quite well argumented reply. Is there danger of damaging the PC, or can I expect higher cpu/gpu temperatures, or something like that?
Again, sorry if sound like I'm arguing, I'm not. I literally have 0 knowledge about PSU quality and didn't even know that it's a thing. 😓

What do you mean no problems? Most PSU issues can't be determined visually until a lot of damage has been done. Nobody's suggested you need a 200-300 Euro PSU. Something a little more expensive would have given you a lot more safety for a lot longer, with a much better warranty.

Your PC isn't likely to blow up or run hotter. But you *have* increased the overall risk to your machine, decreased the time until you need to be an entirely new PSU, and decreased the time your PC will be protected by warranty if something does happen. There's a consequence to going with cheaper-sourced, lower-grade Chinese parts from a less reputable manufacturer.

Now, it's certainly your choice to choose to spend more money on fun parts rather than safety equipment. But the tradeoffs still exist if you make this choice.

 

[rbogomolec]

What do you mean no problems? Most PSU issues can't be determined visually until a lot of damage has been done. Nobody's suggested you need a 200-300 Euro PSU. Something a little more expensive would have given you a lot more safety for a lot longer, with a much better warranty.

Your PC isn't likely to blow up or run hotter. But you *have* increased the overall risk to your machine, decreased the time until you need to be an entirely new PSU, and decreased the time your PC will be protected by warranty if something does happen. There's a consequence to going with cheaper-sourced, lower-grade Chinese parts from a less reputable manufacturer.

Now, it's certainly your choice to choose to spend more money on fun parts rather than safety equipment. But the tradeoffs still exist if you make this choice.

I see... I think imma keep my old PSU and GPU even after the upgrade. If something goes wrong imma just roll back to my old rig and the old smaller 1080p TV. 😅 All I actually wanted in the first place was a bigger tv. But they don't sell 55" and 65" at 1080p or 2k any more. So I had to go with the 4k. And so this whole landslide started... 😓 As for the prices of hardware, I think no one is safe anymore. My friend built a 5000€ rig 6 months ago and has been without his 2000+€ GPU for a month already cuz it malfunctioned and now he's waiting for the manufacturer to send him a new one. Which will take another month at least. As for me, I sometimes regret for not sticking to the old TV, but it was already old and sooner or later I'd have to go for this 4k crap in the end. Not sure if I'm getting too old for this stuff or the technology is simply getting less and less reliable.

 

[geofelt]

Games that you seem to be playing, like sims,mmo and strategy games (vs. fps shooters) tend to be cpu centric. To that end, your 9400 may not be as good as you think for your usage.
Try my test mentioned above limiting graphics.
You will get a better idea of what you need for YOUR games.

 

[rbogomolec]

Games that you seem to be playing, like sims,mmo and strategy games (vs. fps shooters) tend to be cpu centric. To that end, your 9400 may not be as good as you think for your usage.
Try my test mentioned above limiting graphics.
You will get a better idea of what you need for YOUR games.

It actually did quite well till now. Never got above 60'C in any game, usage was also never above 70% per each core. Tried Genshin Impact and Sekiro on 4k, still looked good. That's why I went just for a new GPU. If I had to replace my CPU as well, I would've just kept my old rig. Found a good site that calculates your bottleneck per game, and on 4k it was 4-8% for the games I intend to play. Only huge bottleneck was for Elden Ring (around 20%), but I wouldn't play that even if someone payed me to. When I finish Sekiro I'm done with souls games 😂

 

[geofelt]

Bottleneck calculators are considered as junk science on these forums.

If you see a 70% total cpu utilization, do not assume that you have ample cpu reserve.
Windows will spread out cpu activity among available cores.
You may well have the situation that your critical thread is 100% utilized.
You would not see that if that single thread activity is spread around.