Okay or no way? AMD RX 7800 XT with 560W PSU

[las]

It will work just fine, when Nvidia/AMD/Intel states PSU requirement, they think no-name PSU and you have a quality one, which easily beats the cheaper ones (that always claim higher watts than they are capable of)

Alot of cheap OEM PSUs claim 700-800 or even 1000 watts and most of them don't deliver

 

[JuanPC81]

...
My source 650w / 80(%)+ bronze =520w (is the logic correct)?
...

Incorrect.

Efficiency works in that way: if your PC consume let's say 500w total, this is the 80% in a 80+ bronze one, and the PSU will consume 625w (100%) from the wall.

 

[ecomorph]

When I built my new desktop last year I didn't foresee I would end up adding a +265W TGP GPU later down the road. Last year I wasn't gaming at all, so though the iGPU would do fine, or maybe a entry level GPU... Currently I 'only' have a Fractal Design Ion+2 Platinum 560W. I've started some occasional race games lately though (half an hour here, an hour there... just a few hours a week...), so want something a bit more powerful.
AMD recommends a 700W PSU for the RX 7800 XT, so my PSU is well below that.
However, when I add up the power consumption of my other components (stock i5-13600K, motherboard, 2 DIMMS, 8 fans, 2 NVMe drives) I estimate those consume about 200W when maxed out. Considering another 348W for 20ms power spikes of e.g. the Powercolor Hellhound, that's still within the capacity of my PSU. And in practice I don't expect to max out everything all at once...

I know PSUs are most efficient at 50% load. But if I don't necessarily have to spend €100-150 for a new 700W PSU on top of the €550-600 for the new GPU, I'd rather keep my current PSU.
So... "Okay..." or "No way!!"?

I'm planning on running the 7800XT on my system with a 500W PSU, will post results by the end of this month when prices stabilize.

Any updates? Would be interested in hearing about your results

 

[Kapone33]

Why is there only 1 sku from 1 brand that allows you to monitor your GPU usage in Windows? This would definitely let everyone know what their system consumes without having to guesstimate. Having said that a low power CPU will work fine with a 7800XT using a 600 Watt PSU.

 

[3x0]

Any updates? Would be interested in hearing about your results

No unfortunately, ordered the GPU through a friend in Germany, he'll come mid december.

 

[ecomorph]

Why is there only 1 sku from 1 brand that allows you to monitor your GPU usage in Windows? This would definitely let everyone know what their system consumes without having to guesstimate. Having said that a low power CPU will work fine with a 7800XT using a 600 Watt PSU.

What do you mean? Isn't the GPU power consumption field available on all AIB GPUs through hwinfo?

 

[Solid State Soul ( SSS )]

Nooo no no no no

750w minimum, new GPUs have very high peak power spikes, a low wattage psu would cause problems

 

[AleXXX666]

I see some comments that I indeed already had in mind:
* just try and see... An OCP would be quite obvious
* AMD recommendation is probably based worst case scenario with a healthy headroom, just to cover themselves
* limit to 60fps to reduce power consumption (my 4K ultrawide monitor and 4K TV are 60Hz anyway)
* undervolt for better efficiency
* if I'd buy an factory OC card, revert to stock frequencies

(my CPU is already undervolted btw (-0.075V I believe), but not power capped yet. R23 multi: same performance but 20W less power)

4k 60 hz and fhd 60 hz isn's same lol
what's the point with hz, i still don't get it lol

 

[Oconner]

Back after some time, now, with my ASRock RX 7800XT Phantom Gaming.

I have some reports regarding my used power supply: MSI MAG A650BN 650w.

Well, we know that this source is not tier A, nor is it at the top of tier B.
I live in Brazil, and we recently discovered that MSI changed one of the capacitors in the batches sold here, making the source even less reliable.
(I recommend that anyone living abroad also check out this information)

With my card in hand, I decided to carry out some overclocking tests, with increased power, and to my surprise, all the ones I tried, in fact, had at least worse results in the TIMESPY benchmark, compared to the card without overclocking.

At that moment I didn't have powerful games to test, so it was the best scenario I could do.
I believe that these poor results are due to the limitation of the source, which when greater power was requested, was unable to deliver.

Here is the comparison result:

O overclock utilizado foi o mesmo sugerido pela análise do modelo RX 7800XT Phantom Gaming da TechpowerUp

Just to add:
Under normal conditions, playing games like:
Farcry 6 4k ultra
Farming Simulator 4k ultra
Which was the heaviest I've been able to test so far, the power supply is carrying the card smoothly, without any sign of loss of performance.

 

[3x0]

With my card in hand, I decided to carry out some overclocking tests, with increased power, and to my surprise, all the ones I tried, in fact, had at least worse results in the TIMESPY benchmark, compared to the card without overclocking.

Are you sure the card is stable under OC? Seems like there's error correction happening on VRAM.

 

[Oconner]

Are you sure the card is stable under OC? Seems like there's error correction happening on VRAM.

I had more tests, but it looks like they weren't recorded, just these two.
In fact, not all of them were stable, I carried out some others with less power in OC, which also did not have good results, but were stable.
In short, every OC I've done here, always the performance without OC, had better results.

Now I hope at some point to have a 750w power supply and return OC and see how it behaves.

 

[Chrispy_]

What do you mean? Isn't the GPU power consumption field available on all AIB GPUs through hwinfo?

hwinfo, as well as the default AMD control panel, FRAPs, GPU-Z, OCCT to name just a few.

I have no idea what he's talking about either....

Are you sure the card is stable under OC? Seems like there's error correction happening on VRAM.

Yeah, the average memory clock implies that the VRAM OC is unstable. Given that it's a 256-bit card and each channel is running at almost 20 Gbps, the default bandwidth is overkill for anything except 4K I think. There should be no need to overclock the VRAM at 1080 or 1440p, nor at 4K if using upscaling from a lower resolution.

 

[Kapone33]

What do you mean? Isn't the GPU power consumption field available on all AIB GPUs through hwinfo?

Sorry I actually meant PSU. I was half asleep when I wrote it.

 

[Chrispy_]

Sorry I actually meant PSU. I was half asleep when I wrote it.

I, too, have only just finished my first coffee.

PSU power consumption is a nice-to-have feature, but you can get close enough with a kill-a-watt meter and your PSU's efficiency curve. At most loads we're talking an efficiency factor of within 1-2% for most Gold or higher models, and even cheap kill-a-watt meters often allow you to program correction factors. If you're using 400 Watts and your PSU efficiency is somewhere between 89 and 92W for most of the typical range of your PC's power draw, it's only going to be out by 12W at most, and you could actually tune it to be accurate at the load you're most concerned about, near the maximum output when efficiency is at its lowest, for example.

A $10 kill-a-watt meter is better than overspending on flagship PSU with smart monitoring that's $100 more than equivalent models.

 

[Ruru]

I ran a R9 290 with a good-quality 430W PSU back in the day without any problems. AMD cards are also practically always overvolted from the factory, so with undervolting, you can easily get the power consumption (and temps) down.

 

[Chrispy_]

I ran a R9 290 with a good-quality 430W PSU back in the day without any problems. AMD cards are also practically always overvolted from the factory, so with undervolting, you can easily get the power consumption (and temps) down.

The two 7800XT models I've used both undervolt to 200W at default clocks, and that included a factory overclock in the case of the Nitro+

 

[Ruru]

The two 7800XT models I've used both undervolt to 200W at default clocks, and that included a factory overclock in the case of the Nitro+

My 6700 XT pulls a little over 210W (according to HWInfo64) with undervolt and OC + max power limit. A little drop from AMD's 230W TDP.

 

[freeagent]

As long as you don't intentionally try to peak the PSU, it might be ok.

 

[Chrispy_]

My 6700 XT pulls a little over 210W (according to HWInfo64) with undervolt and OC + max power limit. A little drop from AMD's 230W TDP.

I thought the 7000-series was the first generation of Radeon in ages to have sensors for total board power.

Of the dozens of different RDNA2 cards I've handled, they've only ever reported chip power use, excluding MOSFET efficiency losses, the 2-3 VRM controller SOCs, and any additional power draw (typically 5-10W) for fans and RGBLED, so either you're already ajusting for that when you say 210W, or your 6700XT is actually using about 250W, which is still respecable if you've managed a decent overclock out of it.

 

[Ruru]

I thought the 7000-series was the first generation to give total board power. Of the dozens of different RDNA2 cards I've handled, they've only ever reported chip power use, excluding MOSFET efficiency losses, the 2-3 VRM controller SOCs, and any additional power draw (typically 5-10W) for fans and RGBLED

Oh, you're right. That's just the GPU's value on my case.

 

[Dr. Dro]

it's a quality power supply but personally I wouldn't buy a 7800 XT for that power supply. The 4070 is much much more power efficient.

Also if you're running Blender, Cinema 4D and similar productivity applications you'll want to steer clear of AMD's immature and buggy software suite. CUDA over HIP any day of the week, and Nvidia provides tailored studio drivers for those.

 

[PLAfiller]

Well, if someone's pulling a trigger on a new ATX 3.0 compliant PSU, you basically can't get below 750W as the 12VHPWR must be able to handle 600W. Perhaps the sweet spot will be 850W or so for average person getting a new PSU with this specification. Undervolting is great, but how many people with less wattage PSUs do it? Actually do it? Like I've never undervolted a card to be honest. Is it easy? Dunno. Is it fast to do it? Have no idea. Wouldn't bother unless I am really curious or pressed by the circumstances.

 

[Ferrum Master]

Nooo no no no no

750w minimum, new GPUs have very high peak power spikes, a low wattage psu would cause problems

A long thread and only few tell the most important bit. Some are saying such rubbish things. Even some Nvidia fanboy came in.

It ain't about average currents, but peak currents that can trigger OCP on certain more sensitive PSU's, the thing is that some PSUs protections are set way too high and that's a bad thing, you cannot look just at the rated power here. That's the price calling WATTAGES, hey it is OCP for a reason, not OWP, there is OPP, called correctly over power protection measured in Wats, each reviewer calling these things wrong is deserved to be called an uneducated monkey. Bloody every one forgets what's what and calculate current on each rail or even distinct if there are multiple or a single one and do the math for their each respective PSU they own, cheaper units don't state only the 12V rail capacity as the whole unit power. 7800XT can trigger a power total consumption spikes around 400W if I recall correctly(PCIe a+ 12V PEG), the board limit is 467.8W for Nitro+ at least AFAIK. If you OC it, then higher the average. So do your math with your other peripherals. Intel CPU peaking 200-300W turbo's especially while gaming? I am talking about peaks not averages. Those are different things. Few years ago I could hit the lights out on a 1kW supply using SLI with two overclocked 1080Ti's... yet those are normally ~350W each while on OC. Modern GPU's are indeed more aggressive with current spikes, especially Radeon. They are designed to auto OC and hit the power limits.

650W is a minimum in my books.

Then after all wisemen suggestions we have other threads... hey my Radeon keeps crashing and other stuff... sheesh.

 

[Chrispy_]

it's a quality power supply but personally I wouldn't buy a 7800 XT for that power supply. The 4070 is much much more power efficient.

Also if you're running Blender, Cinema 4D and similar productivity applications you'll want to steer clear of AMD's immature and buggy software suite. CUDA over HIP any day of the week, and Nvidia provides tailored studio drivers for those.

I don't think OP is needing CUDA since their productivity was handled just fine with the Intel IGP, but I'd definitely recommend CUDA for productivity if GPU-acceleration is needed.

Well, if someone's pulling a trigger on a new ATX 3.0 compliant PSU, you basically can't get below 750W as the 12VHPWR must be able to handle 600W. Perhaps the sweet spot will be 850W or so for average person getting a new PSU with this specification. Undervolting is great, but how many people with less wattage PSUs do it? Actually do it? Like I've never undervolted a card to be honest. Is it easy? Dunno. Is it fast to do it? Have no idea. Wouldn't bother unless I am really curious or pressed by the circumstances.

On AMD it's about a 10-second operation in the driver. In the case of the 7800XT:
Performance > Tuning > Custom > Voltage(mv) - change "1150" to "1050" > Apply.
If it ever crashes it means you lost the silicon lottery, try again with "1075" instead.

On Nvidia, you have to install a third-party utility, commonly MSI afterburner and mess around with voltage curves in advanced options. The Nvidia experience sucks, but in their defense, the default voltage curve is usually very good anyway, so simply reducing the power limit slider by 20% is usually good for a big efficiency increase since you usually get 95% of the performance for 80% of the power consumption.

It ain't about average currents, but peak currents that can trigger OCP on certain more sensitive PSU's, the thing is that some PSUs protections are set way too high and that's a bad thing, you cannot look just at the rated power here. That's the price calling WATTAGES, hey it is OCP for a reason, not OWP, there is OPP, called correctly over power protection measured in Wats, each reviewer calling these things wrong is deserved to be called an uneducated monkey.

OCP on PSUs is programmable to kick in after a delay. A decent, non-faulty PSU will not suddenly trigger if there's a 20ms current spike that's barely above spec.

Tests of OCP effectiveness (eg Keysight Oscilloscope testing and whitepapers) show that if an OCP is set to 20ms, it will trigger at ~24ms if the current exceeds the limit by 100% and 600ms if the current only exceeds the limit by 25%. Since we're talking about the fixed 12V rail, power and current are interchangeable - A CPU+GPU combination drawing 720W from a 600W supply is only exceeding OCP by 20% at most (likely less, as any PSU manufacturer would be mad to set OCP at exactly the rated current). This means that properly-set OCP should absolutely handle big 20ms current/power spikes on the 12V rail and likely 50ms spikes too.

The issue of course is whether the PSU is actually a quality unit with properly-set OCP!

Almost every piece of silicon in a modern PC will have current/power spikes because it all relies on microcontrollers reacting to changes and they're not instant. This isn't a new thing, it's been par for the course for 20+ years. The only reason it's come to light is because RDNA2 and Ampere were the hungriest GPUs we'd ever seen up until that point and GPU power draw had increased year on year much faster than typical PSUs had, so there was this sudden discrepancy in the market and reviewer test-beds.

To get more info/insight on this, you'd need to hit up @crmaris or @jonnyGURU.

 

[Macro Device]

7800XT can trigger a power total consumption spikes around 400W if I recall correctly(PCIe a+ 12V PEG), the board limit is 467.8W for Nitro+ at least AFAIK.

It's not so bad.

I agree with you on considering power spikes as the main measurement but 7800 XT isn't so dramatically overcurrenting as its predecessors. Quality 560 W PSU will totally do fine if the GPU is both undervolted and underclocked. No guarantee it'll behave well under the default, especially if we talk the most factory overclocked models, settings.

On AMD it's about a 10-second operation in the driver. In the case of the 7800XT:
Performance > Tuning > Custom > Voltage(mv) - change "1150" to "1050" > Apply.
If it ever crashes it means you lost the silicon lottery, try again with "1075" instead.

This only works if you need more speed at the same wattage. If you wanna lower the wattage you need to lower the maximum clock as well. Usually, lowering it by 200 reduces wattage by 25 to 40 percent.