Underclock a 6800XT to run on a 550W power supply? (2024)

Why would you cripple a brandnew 6800XT?
I'd say , get a proper PSU and be done with it.

BTW you mean a BE QUIET 550W Dark Power 10 PSU?
Maybe it's good enough then.

Mistral said:

So, the planets aligned and I somehow got my hands on a reference 6800XT (I was looking for a regular 6800 or a 6700XT).
However, the PC it's intended to go in has a 550W Dark Power 10 PSU, an 4690k, 3 HHDs and 5 fans.
In my head, with a bit of an underclock there shouldn't be a problem. Say, I'm too lazy to get a new PSU and rewire everything...
What would be a reasonable frequency to run the card at?

Click to expand...

I agree with @P4-630 to find a way to obtain a larger PS.

If that's just not possible, rather than underclocking, I'd just set a lower power limit in the AMD settings and let the clocks do what they can with the power budget.

impero said:

Well this is kinda like i buy a new BMW M5 and i tune it to cut out some horses to consume less gasoline
If i were the owner i would look to a better PSU and let the video card as it is

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See Also

Sound keeps getting muted in Windows 11 between useSeasonic to Launch New MagFlow 120 ARGB FanSurround problems with 6800XT

Welcome to Norway bro There's no point for HP when you can't go fast anyway

Aside the joke I understand people doing this. I myself been doing this with my 6900xt just to have a profile with lower clocks and voltage.

Some advice:
1) if you OVERCLOCK the CPU then the ROUGH estimate for your total system in worst-case is about 500W power draw. It would likely be closer to 400W when gaming.
(up to roughly 200W system not counting GPU + about 300W for RX6800XT)

2) The FREQUENCY of the card isn't the main issue it's the voltage (and thus power draw). You might consider dropping to 95% of the max frequency though and then use your GPU manufacturer's OC tool to UNDERVOLT... I would do the same with the CPU if possible (I use Asus' AI Suite 3)

3) Putting CPU to no more than around 4.5GHz, optimizing the voltage and doing the GPU undervolt/95% frequency might get you closer to 300W under gaming load with spikes just over 400W. There are guides, and note that setting a cap of 95% the current max frequency does not mean gaming performance drops to 95%. You can probably drop a lot of power draw and only lose 3% performance.

4) That PSU will probably work without the tweaks I mentioned but any power spikes might cause issues. Hard to say.

5) the recommended WATTAGE for graphics cards is often high because it assumes a worst-case for the rest of the system. So you have to investigate to estimate power draw. I did that for you.

6) That CPU will be a big bottleneck in some games (it will vary a lot), although at this point I'd hold off and get a system that supports PCIe v5, DDR5 and also has low power draw. The new Intel CPU has PCIe v5 but the power draw is high (it's not just power draw... it's also the heat that dumps into your room. That's an issue for me. If you draw 500W of power it's 100% identical to having a 500W space heater).

7) So I'd recommend something like this upcoming AMD (or similar Intel):
a) AM5 socket
b) 8C/16T CPU (R7-7700x ?)
c) 32GB DDR5 (2x16GB)

8) I can't predict power draw for that but it MIGHT not exceed 100W when gaming (plus GPU).

9) So in summary, your system SHOULD work without undervolting but I'd probably try to optimize that to get closer to 400W as power spikes can cause instability. And then plan your core system upgrade carefully.

UPDATE:
Here's how to estimate how much the CPU is bottlenecking the GPU:
1) disable VSYNC or any FPS cap
2) use any OSD to display your "GPU Usage"
3) if GPU Usage is close to 100% you have minimal to no CPU bottleneck
4) a GPU usage of 50% would roughly indicate you need a CPU of 2x the performance per core to eliminate that bottleneck
5) a GPU Usage of 80% would indicate you need a CPU of roughly 1.25x... (100/80)

It's a great estimate, however you can still have a good FPS yet have a poor gaming experience if the low number of CPU cores results in missed frames. So basically 6+ cores in some games is really needed for SMOOTH gaming. A high-end 8-core CPU that comes out in 2022 will have a really long life.

PLENTY of great games will run great with your i5 CPU still. But many won't. I'd investigate any game you plan to buy to see how well it runs with your CPU. "gamename cpu core scaling"

maxfly said:

Im to lazy to google it. Whats the recommended wattage for his 6800xt?

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About 280W for the card only during gaming.

Here's the CPU info I got (so system minus the Graphics Card).

So that 180W is system power draw in a stress test.

So add together and it's roughly 500W in worst-case (400W(ish) average gaming?) but you still have spikes which is why I suggested perhaps a bit of undervolting CPU/GPU.

P4-630 said:

Why would you cripple a brandnew 6800XT?

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I do it in my HTPC, still has plenty of beef with lower power consumption and heat. Its much more efficient!

P4-630 said:

Why would you cripple a brandnew 6800XT?
I'd say , get a proper PSU and be done with it.

Click to expand...

Because it was the cheapest HDMI 2.1 card I could find and I don't feel like re-wiring the PC. The beQuiet will have to do for now - not looking for crazy-high frames, that PC is hooked to a TV anyway.

maxfly said:

Id go ahead and find a way to squeeze an ssd in there while your upgrading your psu

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Already got two in there in addition to the HDDs, but as they are light on the PSU so I didn't mention.

From the comments as a whole, I gather reducing the power limit a bit and setting a limiting the max FPS should be enough. Thanks!

Will post here again if the whole thing goes up in smoke

Mistral said:

So, the planets aligned and I somehow got my hands on a reference 6800XT (I was looking for a regular 6800 or a 6700XT).
However, the PC it's intended to go in has a 550W Dark Power 10 PSU, an 4690k, 3 HHDs and 5 fans.
In my head, with a bit of an underclock there shouldn't be a problem. Say, I'm too lazy to get a new PSU and rewire everything...
What would be a reasonable frequency to run the card at?

Click to expand...

Look at your label on the psu and compare it to this list. Get us the model number please.

eidairaman1 said:

Look at your label on the psu and compare it to this list. Get us the model number please.

https://www.realhardtechx.com/index_archivos/Page1354.htm

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It's a Be Quiet 550W Dark Power Pro 10 PSU. (FSP according to your list)

you want to run one of the fastest graphics cards on the planet with a 2013 quadcore and a PSU that can't handle it in the first place?

you need a new PSU, CPU, Motherboard and RAM at least.

Lil update: mostly all runs well - having some HDMI issues with surround that weren't there with the RX580, but it might actually be the TV messing around. I put the effort to calculate system power and even during peak it wouldn't get above 95% of the PSU's rating. Reduced the power limit on the 6800XT anyway... interestigly AMD lets you do -6% at the most.

GerKNG said:

you want to run one of the fastest graphics cards on the planet with a 2013 quadcore and a PSU that can't handle it in the first place?

you need a new PSU, CPU, Motherboard and RAM at least.

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Thank you for telling me what I need without paying attention why I'm asking in the first place.

You'll be fine with the Dark Power 10 until you can afford a new PSU for peace of mind. The CPU overclock is mild so I'm guesstimating a 400-420W load in gaming which is totally doable on a decent 550. IMO you don't even need to undervolt. The only potential problem I see are initial power spikes which could trigger the OCP on the PSU, though from past experience OEMs always set OCP way too high so that might not happen.

I would upgrade the PSU as soon as possible though.

Mistral said:

So, the planets aligned and I somehow got my hands on a reference 6800XT (I was looking for a regular 6800 or a 6700XT).
However, the PC it's intended to go in has a 550W Dark Power 10 PSU, an 4690k, 3 HHDs and 5 fans.
In my head, with a bit of an underclock there shouldn't be a problem. Say, I'm too lazy to get a new PSU and rewire everything...
What would be a reasonable frequency to run the card at?

Click to expand...

Undervolt it, not difficult. If you want the best power efficiency, you can even lower underclock it a bit for further undervolting

Frankly, the "quiet" setting in the drivers alone seems to be enough, as it does it's best to keep the card under 240W. For whatever reason though, the "quiet" preset also disables the "fan stop", which is quite absurd and and hopefully just a driver oversight that gets fixed at some point.

In the end, I had some extra time yesterday and swapped the PSU even though the BeQuiet was probably going to be fine, from what I tested. I did have an EVGA P2 750W laying around, but that thing is a bit chunky for the case so I slapped in a Seasonic PX-650 for peace of mind. I do have some gripes with that Focus unit, but overall it's cleaner and not noticeably noisier than the BeQ.

This whole thread was on me for being lazy to rewire the PC, thank you to those who humored me.

Mistral said:

I'm too lazy to get a new PSU and rewire everything...

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Your motherboard is testing your psu every time you boot your system, so that you won't become power ridden using your gpu. Think of your motherboard and all the things it could do with ample power... like allowing you to start your os.