ARC power limit bypass found

[Karath]

I have been digging around in ARC drivers for awhile to find fixes to some display related issues and found a way to reliably extend the GPU power limit slider in ARC control.

1. Set power limit in ARC Control to maximum
2. Kill the process for ARC Control
3. Stop the Intel ARC Control Service
4. disable/enable the GPU in device manager or use CRU Restart64 application to do this for you.
5. Start ARC Control
6. Start Intel ARC Control Service
7. Set the power limit to its new maximum

First run through this procedure will give you a 273w limit, however... you can repeat this procedure and the limit will go up again to 327w. I would assume you could push the wattage limit as far as you want by repeating these steps.

Borderlands 3 benchmark at stock

Borderlands 3 benchmark at 327w power limit with core clocks locked at 2700mhz. Using a 120mm delta fan blowing at the card to keep temps in check.

 

[Fouquin]

I have been digging around in ARC drivers for awhile to find fixes to some display related issues and found a way to reliably extend the GPU power limit slider in ARC control.

View attachment 274506

1. Set power limit in ARC Control to maximum
2. Kill the process for ARC Control
3. Stop the Intel ARC Control Service
4. disable/enable the GPU in device manager or use CRU Restart64 application to do this for you.
5. Start ARC Control
6. Start Intel ARC Control Service
7. Set the power limit to its new maximum

First run through this procedure will give you a 273w limit, however... you can repeat this procedure and the limit will go up again to 327w. I would assume you could push the wattage limit as far as you want by repeating these steps.

Borderlands 3 benchmark at stock

Borderlands 3 benchmark at 327w power limit with core clocks locked at 2700mhz. Using a 120mm delta fan blowing at the card to keep temps in check.

How is the performance with the default power limit (228W) and your 2700MHz OC settings? Just curious if this isn't a GUI bug or if it's actually storing the previous power limit value.

 

[Karath]

How is the performance with the default power limit (228W) and your 2700MHz OC settings? Just curious if this isn't a GUI bug or if it's actually storing the previous power limit value.

Stock power limit is too restrictive to hold 2700 at all.

Power usage confirmed with HWInfo64.

It is taking 300CFM+ of air flow on the heatsink to keep the core at ~80c, it is drawing some serious power. The same fan setup at stock keeps temps in the 60c range.

 

[chrcoluk]

This is definitely not worth it.

 

[Karath]

This is definitely not worth it.

Overclocking is rarely worth it with modern hardware. It takes an edge case to actually gain more than a few percent.

That being said, a 16% performance gain on a core only OC is nothing to sneeze at. And there is a waterblock for A770 LE.

 

[Fouquin]

Overclocking is rarely worth it with modern hardware. It takes an edge case to actually gain more than a few percent.

That being said, a 16% performance gain on a core only OC is nothing to sneeze at. And there is a waterblock for A770 LE.

This makes me wish for Skatterbencher's Arc tool, and some way to more effectively tune the power response. It's clear the VF curve is following a combination of core temperature, power limit, and core voltage to establish the load clock state, so blowing one of those out of the water increases the sustained clock speed. I found decent luck with simply overvolting +60mV and leaving power limit at 200W and keeping the card under 70C, as well as simply dragging the power limit to the moon and letting it warm up normally. My card struggles to hit 2600MHz, however the most recent driver (3959) has helped it a bit.

 

[Karath]

This makes me wish for Skatterbencher's Arc tool, and some way to more effectively tune the power response. It's clear the VF curve is following a combination of core temperature, power limit, and core voltage to establish the load clock state, so blowing one of those out of the water increases the sustained clock speed. I found decent luck with simply overvolting +60mV and leaving power limit at 200W and keeping the card under 70C, as well as simply dragging the power limit to the moon and letting it warm up normally. My card struggles to hit 2600MHz, however the most recent driver (3959) has helped it a bit.

It feels like they lifted the power management directly from the Core CPU series TBH.

It takes +150mv (and an insane power limit) to lock it at 2700, I can get to 2800 by combining +165mv with a bit of tweaking of the GPU performance boost setting, but nothing is remotely stable above 2700.

Hilariously, my A750 hits ~2600 inside of the 228w limit most of the time without temp problems. The A770 is always at the temp or power limit and tends to run at 2200-2400 no matter how hard I push the sliders in ARC Control. It desperately needs fan speed control.

Makes me wonder just how far I can push the A770 under water or other more extreme cooling. Hot power hungry chips tend to be phenomenal overclockers if you can cool them.

 

[AsRock]

Any thing over 300w some chance some thing to fail ?, are they not 1x8(150w)+1x6 (75w) then 75w pci-e slot.

And do you know if it's taking it from the 6\8 pin or trying to get it though the PCI-e slot.

 

[Karath]

Any thing over 300w some chance some thing to fail ?, are they not 1x8(150w)+1x6 (75w) then 75w pci-e slot.

Eh. PCIe slot is more like 66w for 12v. The 6 and 8 pin connectors can take WAY over their rated power without issues though.

The GPU seems to run out of steam around this power level too, cant OC memory to get anymore bandwidth.

 

[AsRock]

Eh. PCIe slot is more like 66w for 12v. The 6 and 8 pin connectors can take WAY over their rated power without issues though.

Well defiantly want pictures when\if shit hits the fan.

 

[Fouquin]

Well this trick certainly works.

 

[Dristun]

Lol, that's super cool, man, I need to try this out. When I played with OC stuff in Arc Control before it seemed to me that raising voltage didn't really offer that much (and at some boost+voltage offset combos performance regressed) at 228W and that the main thing holding the card back is the power limit. Now that EK's waterblock makes a bit more sense, haha.

 

[chrcoluk]

Overclocking is rarely worth it with modern hardware. It takes an edge case to actually gain more than a few percent.

That being said, a 16% performance gain on a core only OC is nothing to sneeze at. And there is a waterblock for A770 LE.

its a power limit bypass so a heavy power efficiency cost. I do get its a nice find though, for people into this.

 

[R-T-B]

lol intels drivers are so bad, they can't even enforce their own power limit.

Good find.

 

[Karath]

lol intels drivers are so bad, they can't even enforce their own power limit.

Good find.

You used to be able to do something similar with AMDs Wattman. And you could edit NVidia/AMD vBIOS's to change power limits for a long time.

Meaning Ive not had this kind of overclocking control on a new part without hardware hacks for... quite awhile. Kinda makes me feel nostalgic.

 

[pavle]

An interesting driver oversight from wintel, no doubt. Looks like the card/GPU doesn't like being that high though, linear scaling from 2400MHz and 225W would be ~263W, but here we have 311+. I'd say it's more of a curiosity as to how this GPU behaves than a really useful thing, hence factory limit.

 

[Karath]

An interesting driver oversight from wintel, no doubt. Looks like the card/GPU doesn't like being that high though, linear scaling from 2400MHz and 225W would be ~263W, but here we have 311+. I'd say it's more of a curiosity as to how this GPU behaves than a really useful thing, hence factory limit.

Power scaling is never linear, its more... exponential. So the extra power required was expected.

BL3 at stock is only running ~2200 for 190w, so +500mhz for roughly +120w.

 

[R-T-B]

You used to be able to do something similar with AMDs Wattman.

It was bad then too.

And you could edit NVidia/AMD vBIOS's to change power limits for a long time.

I don't mind this though. Sort of wish you could still VBIOS edit. I mean that's pretty detectable for a "warranty void" event.

 

[Karath]

It was bad then too.


I don't mind this though. Sort of wish you could still VBIOS edit. I mean that's pretty detectable for a "warranty void" event.

Intel is writing to the firmware when you change clocks already. So 100% there is evidence of what you are doing because of how the hardware works.

 

[pavle]

Power scaling is never linear, its more... exponential...

Oh it is linear up to certain frequency, above that is what you are experiencing.

 

[R-T-B]

Intel is writing to the firmware when you change clocks already. So 100% there is evidence of what you are doing because of how the hardware works.

lol wut. They write to the vbios ROM to change clocks?

No. No one else does that. That's outright awful.

 

[Karath]

Oh it is linear up to certain frequency, above that is what you are experiencing.

nope, its a curve from all the way down at ~130w. You get ~120mhz or so per 10w at 130-150, ~90mhz or so per 10w from 150-170, and so on.

lol wut. They write to the vbios ROM to change clocks?

No. No one else does that. That's outright awful.

I dont think its the ROM area of flash, more like a partition of it that is used like NVRam on a MB. Regardless, it is very odd. And because its done like this, you can blow the power limit out to obscene levels with the bypass.

Snagged the top A770 graphics score on Time Spy.
Time Spy Result

 

[Fouquin]

nope, its a curve from all the way down at ~130w. You get ~120mhz or so per 10w at 130-150, ~90mhz or so per 10w from 150-170, and so on.


I dont think its the ROM area of flash, more like a partition of it that is used like NVRam on a MB. Regardless, it is very odd. And because its done like this, you can blow the power limit out to obscene levels with the bypass.

Snagged the top A770 graphics score on Time Spy.
Time Spy Result
View attachment 274631

Really annoyed that Time Spy and 3DMark11 don't run properly on my card with the current driver. Time Spy hard locks over 2650MHz no matter the power, 190W up to 300W, but is completely capable of running Port Royal, Fire Strike, Elden Ring, Darktide, and Vantage at 2720-2750MHz at 250W. So frustrating. Others are getting 2900MHz out of their LEs and this one is just a dud.

 

[Karath]

Really annoyed that Time Spy and 3DMark11 don't run properly on my card with the current driver. Time Spy hard locks over 2650MHz no matter the power, 190W up to 300W, but is completely capable of running Port Royal, Fire Strike, Elden Ring, Darktide, and Vantage at 2720-2750MHz at 250W. So frustrating. Others are getting 2900MHz out of their LEs and this one is just a dud.

Turn off GPU performance boost altogether, so set it to 1 if you already played with it. Another oddity of the software is that setting the sliders to zero just does... nothing.

Then just crank voltage offset up to get the clock you need.

I only use performance boost to add a little to an already big OC achieved with voltage offset. Mainly because I find that more boost = more instability at higher clocks/volt offsets.

 

[Fouquin]

Turn off GPU performance boost altogether, so set it to 1 if you already played with it. Another oddity of the software is that setting the sliders to zero just does... nothing.

Then just crank voltage offset up to get the clock you need.

I only use performance boost to add a little to an already big OC achieved with voltage offset. Mainly because I find that more boost = more instability at higher clocks/volt offsets.

This is already what I'm doing. Also using the temp limit for minor adjustments, as the 84-89 range will pull up or down the frequency shift under heavy load.