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Radeon RX 6700, 6700 XT & 6750 XT users club

Hi! I've started trying to undervolt my XFX RX 6700. And I see on Youtube, that people increase the Power Limit. For undervolting. But I need to reduce consumption. And it seems to me logical, to limit it. What is the best thing to do with Power Limit?

I haven't touched the Power Limit yet. I gradually reduced the value in the Voltage field from 1200 mV to 1080 mV. The consumption is almost the same as without my intervention. It was 140, now it's 138 under load in Furmark and Metro Exodus. I reduced the Voltage to 1050 mV. The situation did not change. I see, that other people have decreased the chip's voltage to somewhere around these values.
And I'm interested in the value that I highlighted on the screen.

View attachment 320082

Do I need to get lower values than this one, highlighted in blue for noticeable results?

And a more general question, do I do any mistakes?

0. Your GPU as you stated above defaults at 140 W. This is the power it's limited by BIOS.
1. By adjusting voltage, you offset the voltage-frequency curve so your GPU hits higher clocks whilst staying in the same power level.
2. The lower you set your voltage the higher will be the frequency given you don't move the power limit slider.

All this leads to doing things this way if you don't need any speed boost and you're only hunting energy saving:

0. Reset the GPU to the stock values and monitor your GPU clock and wattage. Write them down somewhere or just remember them if your brain functions properly (unlike mine).
1. Move the voltage slider until you get stability issues and set it about 20 mV higher than that when you found an unstable one.
2. Decrease the maximum frequency slider until you get the frequency you had at stock settings minus 50 MHz (minus 200 MHz if you're hunting EXTREME efficiency whatever it takes).
3. Test if everything is still stable in every benchmark and game you can come up with.
4A. In case it is you start compensating lost performance with increasing VRAM bandwidth. Usually RX 6700 GPUs allow you to straight up max the slider out. 2110 MHz is possible on 100% GPUs.
4B. In case you have some stability issues you should increase voltage by 5 mV increments until it stops glitching/crashing/etc. Then you follow it up with increasing VRAM speed.
5. You are allowed to move your power limit slider to the left as well, yet this can lead to poor framerate stability: GPU doesn't crash but you don't feel smoothness anymore. You'd rather let it be at no offset position.

Unfortunately, this is all you can do about it.

1699034584836.png
1699034648289.png
1699034693057.png
 
Last edited:
Hi! I've started trying to undervolt my XFX RX 6700. And I see on Youtube, that people increase the Power Limit. For undervolting. But I need to reduce consumption. And it seems to me logical, to limit it. What is the best thing to do with Power Limit?

I haven't touched the Power Limit yet. I gradually reduced the value in the Voltage field from 1200 mV to 1080 mV. The consumption is almost the same as without my intervention. It was 140, now it's 138 under load in Furmark and Metro Exodus. I reduced the Voltage to 1050 mV. The situation did not change. I see, that other people have decreased the chip's voltage to somewhere around these values.
And I'm interested in the value that I highlighted on the screen.

View attachment 320082

Do I need to get lower values than this one, highlighted in blue for noticeable results?

And a more general question, do I do any mistakes?
I suppose if you lower the max frequency you will consume less power. That will have an impact on the performance level.

But don't set your expectations too high, you're undervolting 0.12V so the reduction is only marginal. Same goes for the power usage.
 
0. Your GPU as you stated above defaults at 140 W. This is the power it's limited by BIOS.
1. By adjusting voltage, you offset the voltage-frequency curve so your GPU hits higher clocks whilst staying in the same power level.
2. The lower you set your voltage the higher will be the frequency given you don't move the power limit slider.

All this leads to doing things this way if you don't need any speed boost and you're only hunting energy saving:

0. Reset the GPU to the stock values and monitor your GPU clock and wattage. Write them down somewhere or just remember them if your brain functions properly (unlike mine).
1. Move the voltage slider until you get stability issues and set it about 20 mV higher than that when you found an unstable one.
2. Decrease the maximum frequency slider until you get the frequency you had at stock settings minus 50 MHz (minus 200 MHz if you're hunting EXTREME efficiency whatever it takes).
3. Test if everything is still stable in every benchmark and game you can come up with.
4A. In case it is you start compensating lost performance with increasing VRAM bandwidth. Usually RX 6700 GPUs allow you to straight up max the slider out. 2110 MHz is possible on 100% GPUs.
4B. In case you have some stability issues you should increase voltage by 5 mV increments until it stops glitching/crashing/etc. Then you follow it up with increasing VRAM speed.
5. You are allowed to move your power limit slider to the left as well, yet this can lead to poor framerate stability: GPU doesn't crash but you don't feel smoothness anymore. You'd rather let it be at no offset position.

Unfortunately, this is all you can do about it.

Problems with smoothness usually means unstable VRAM OC. Same with sudden WHEA "Cache Hierarchy Error" error reports.
 
Beginner Micro Device's recommendations are good. Since you want lower power, I don't find any problem with lowering your Power Limit first. I haven't done this with a Radeon GPU yet as I have no interest/need but I do all the time with a Nvidia 1050 Ti and it behaves just fine, just limiting itself to say 60W instead of 70. Clocks go from 1780 to 1730 average but otherwise only a small performance loss. Should be the same with these cards.

And this works in tandem with all the other sliders. Finding your lowest undervolt will allow slightly higher clocks when power limited so that's always good. Finding your highest 100% stable VRAM will also allow more performance with just a couple of extra watts expended there. I always back off about 20 MHz on the VRAM and Core clocks after finding your stable ones, just for a buffer.
 
Problems with smoothness usually means unstable VRAM OC. Same with sudden WHEA "Cache Hierarchy Error" error reports.
Are there cards which won't take the artificially limited 2150MHz? :eek:
 
Are there cards which won't take the artificially limited 2150MHz? :eek:
Those are just known symptoms to watch for, when OC'ing the VRAM. My Navi10 also had a limit like that for core, where I literally couldn't set it to an unstable point.
 
Those are just known symptoms to watch for, when OC'ing the VRAM. My Navi10 also had a limit like that for core, where I literally couldn't set it to an unstable point.
I've just got used to artifacting with too high VRAM OC :confused:
 
I've just got used to artifacting with too high VRAM OC :confused:
OTOH, Nvidia, appears to usually have just a BIOS-coded watt limiter. Especially GTX 16 series.
 
0. Your GPU as you stated above defaults at 140 W. This is the power it's limited by BIOS.
1. By adjusting voltage, you offset the voltage-frequency curve so your GPU hits higher clocks whilst staying in the same power level.
2. The lower you set your voltage the higher will be the frequency given you don't move the power limit slider.

All this leads to doing things this way if you don't need any speed boost and you're only hunting energy saving:

0. Reset the GPU to the stock values and monitor your GPU clock and wattage. Write them down somewhere or just remember them if your brain functions properly (unlike mine).
1. Move the voltage slider until you get stability issues and set it about 20 mV higher than that when you found an unstable one.
2. Decrease the maximum frequency slider until you get the frequency you had at stock settings minus 50 MHz (minus 200 MHz if you're hunting EXTREME efficiency whatever it takes).
3. Test if everything is still stable in every benchmark and game you can come up with.
4A. In case it is you start compensating lost performance with increasing VRAM bandwidth. Usually RX 6700 GPUs allow you to straight up max the slider out. 2110 MHz is possible on 100% GPUs.
4B. In case you have some stability issues you should increase voltage by 5 mV increments until it stops glitching/crashing/etc. Then you follow it up with increasing VRAM speed.
5. You are allowed to move your power limit slider to the left as well, yet this can lead to poor framerate stability: GPU doesn't crash but you don't feel smoothness anymore. You'd rather let it be at no offset position.

Unfortunately, this is all you can do about it.

Thank you a lot.

1. I need only energy saving and am ready to get even a little productivity shortage. And maybe, it is not necessary to compensate - 50 MHz for the GPU with help of memory overclocking
2. I don't understand that part "2. The lower you set your voltage the higher will be the frequency given you don't move the power limit slider."
3. I thought, that I could decrease power usage just with the help of moving Voltage to the left side
4. Next step - try to try steps from your second list
 
Problems with smoothness usually means unstable VRAM OC.
Not always though. Sometimes it's just GPU clock fluctuates too hard and thus, your frametime graph is a spiky mess. This is why I don't recommend lowering the power limit and instead, I recommend lowering voltage and frequency.

And maybe, it is not necessary to compensate - 50 MHz for the GPU with help of memory overclocking
Of course it's unnecessary but it's like... +0.1 W total wattage for a decent amount of additional performance. You will never notice increased heat.
I don't understand that part "2. The lower you set your voltage the higher will be the frequency given you don't move the power limit slider."
Let's imagine you have a GPU that's set to work at 2500 MHz at 1200 mV, 2600 MHz at 1300 mV, and 2650 MHz at 1400 mV. Its lowest possible resistance is rated 0.01 Ohm and its maximum TDP is rated 144 W. This way the GPU will max itself out at 2500 MHz (1200 mV * 1200 mV / 0.01 Ohm = 144 W) and will be forced to lower its clocks (below theoretical max of 2650) if the 3D load is too hard to stay at more than 1200 mV.

Now you adjusted the slider to -100 mV, resounding 2500 MHz at 1100 mV, 2600 MHz at 1200 mV, and 2650 MHz at 1300 mV. This GPU is still not capable of running at 2650 MHz with 100% uptime but it now maxes out at 2600 MHz instead of 2500. And at 2500, it now will have 1100 mV * 1100 mV / 0.01 Ohm = 121 W theoretical maximum power consumption. But as far as BIOS allows this GPU to run at 144 W, instead of saving electricity, the GPU will just benefit from increased performance.
1699081007171.png

This is why I told you to adjust the maximum frequency slider to lower values. The voltage-frequency curve is only affected by the voltage slider, and the max frequency slider manifests the ceiling. At around 2100 to 2300 MHz, lowering your GPU clock becomes pointless since the wattage lowers slower than the performance at this point.

Are there cards which won't take the artificially limited 2150MHz? :eek:
Yes. My GPU totally dislikes fast timings at any clock but works wonders at 2150 MHz with default timings though.
 
Thank you a lot.

1. I need only energy saving and am ready to get even a little productivity shortage. And maybe, it is not necessary to compensate - 50 MHz for the GPU with help of memory overclocking
2. I don't understand that part "2. The lower you set your voltage the higher will be the frequency given you don't move the power limit slider."
3. I thought, that I could decrease power usage just with the help of moving Voltage to the left side
4. Next step - try to try steps from your second list
Just lower the max frequency until the performance gets lower than what you need and increase a bit again. The power draw will get lower without doing anything else.
 
How, when half of your syringe is the oily liquid stuff and the hard part is stuck on the bottom? :kookoo: You can sugar-coat it any way you want to, but it's still a problem, and it's still the main reason why the MX-5 was discontinued so soon. Thermal paste should not separate straight out of the factory, just like no other paste does. Ever. The fact that you took the effort to mix it up into a usable consistency doesn't mean it's normal.

I'm pretty sure the difference in between MX6 and MX5 is negligible.

The oil is in there to keep the paste from turning into a hard core. It does'nt mean that whenever i try to extract something everything is hard.

Your right in the product being discontinued for a reason, but really i encounter zero issues with it.

The paste is still better then the stock stuff what they put onto it. The largest increase was the difference in between GPU and Hotspot temp. I'd say it's within line of around 10 degree now which is excellent knowing the situation before was sometimes 30 degree difference.

Leaves a bit of headroom in regards of power, overclocking and more.
 
The paste is still better then the stock stuff what they put onto it. The largest increase was the difference in between GPU and Hotspot temp. I'd say it's within line of around 10 degree now which is excellent knowing the situation before was sometimes 30 degree difference.
Would've been interesting to test between the stock paste vs MX-4 but I changed the whole cooler when I took the original out.
 
Would've been interesting to test between the stock paste vs MX-4 but I changed the whole cooler when I took the original out.

If i put a washer in between i'm sure the temps could be even better.


But it's at your own risk - as pressure is increasing.
 
My 6700 XT 12GB is on the way and will arrive tomorrow! (hopefully)
 
Not always though. Sometimes it's just GPU clock fluctuates too hard and thus, your frametime graph is a spiky mess. This is why I don't recommend lowering the power limit and instead, I recommend lowering voltage and frequency.
This is like the issue I had with GTA V, when the driver apparently thinks there's not enough work to do. I get random major clock drops and FPS drops along with it. This was happening even when not bouncing off of the watt limiter.
 
It's just a curse of RAGE. GTA IV couldn't load hardware properly and thus, 40 FPS even on RTX 2080 Ti.
GTA V gets MASSIVE stutters once you go beyond ~150 FPS or where its engine stops responding properly.

driver apparently thinks there's not enough work to do
Maximise settings, apply virtual super resolution then...
 
It's just a curse of RAGE. GTA IV couldn't load hardware properly and thus, 40 FPS even on RTX 2080 Ti.
In my case, the clock would drop in some places and the FPS easily plunges down to 50 FPS and possibly less! (But that's on V, not IV) (Never played IV)
 
Huh, not much of a jump from an RX580 as i thought :D

i mean the frame rates are nice at maxxed out settings, but visually tbh i dont know :p

im at 1440p 75Hz with freesync

1699373658015.png


probably need to play a bit MOAR :D
 
The 6700XT should be 150% faster at the same power consumption.

relative-performance_1920-1080.png


relative-performance_2560-1440.png


It's a good upgrade in my opinion - very efficient, designed for WQHD and more.
 
The 6700XT should be 150% faster at the same power consumption.

relative-performance_1920-1080.png


relative-performance_2560-1440.png


It's a good upgrade in my opinion - very efficient, designed for WQHD and more.
yes the efficiency sure is there. its not that hot.

most of my games arent well optimised and its usually more CPU dependent like cities skylines, KSP etc.
 
Huh, not much of a jump from an RX580 as i thought :D

i mean the frame rates are nice at maxxed out settings, but visually tbh i dont know :p

im at 1440p 75Hz with freesync

View attachment 320562

probably need to play a bit MOAR :D
I upgraded from 1080 Ti though I upgraded from 1080p to 4K at the same time so there's a huge difference in my case. :D
 
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