Question Higher score in TimeSpy, with lower voltage. Why?

[bpanugget]

I recently got a 6800xt Merc 319 Core from XFX. Long story short, it over clocks very well, but it has presented me with a scenario that I've never seen before, outside of heat related issues. The best Graphics score I've been able to achieve is a 21271. That is with the following settings:

Min Frequency: 2500mhz
Max Frequency: 2600mhz
Voltage: 1000 Mv
VRam Speed: Max (2150mhz)
Fast Timings enabled
Smart Access Memory enabled
Power Limit Maxed

Thinking that maybe I could increase the score slightly by increasing the voltage, I put it up to 1100 Mv. Everything else stayed the same. My score dropped dramatically to 17962. This was repeated a few times. As soon as I put the Mv back down to 1000, my scores went back up into the 21200 range. At first I thought it was a heat related issue due to the increased voltage, but that wasn't it, as my temps didn't really change much (I usually sit around 70 degrees under load). Power consumption was roughly the same as well, and I'm hitting nowhere near my PSUs 850 watt rating.

What, besides heat could be slowing down the card when the voltage is increased?

 

[Alan Alan]

I recently got a 6800xt Merc 319 Core from XFX. Long story short, it over clocks very well, but it has presented me with a scenario that I've never seen before, outside of heat related issues. The best Graphics score I've been able to achieve is a 21271. That is with the following settings:

Min Frequency: 2500mhz
Max Frequency: 2600mhz
Voltage: 1000 Mv
VRam Speed: Max (2150mhz)
Fast Timings enabled
Smart Access Memory enabled
Power Limit Maxed

Thinking that maybe I could increase the score slightly by increasing the voltage, I put it up to 1100 Mv. Everything else stayed the same. My score dropped dramatically to 17962. This was repeated a few times. As soon as I put the Mv back down to 1000, my scores went back up into the 21200 range. At first I thought it was a heat related issue due to the increased voltage, but that wasn't it, as my temps didn't really change much (I usually sit around 70 degrees under load). Power consumption was roughly the same as well, and I'm hitting nowhere near my PSUs 850 watt rating.

What, besides heat could be slowing down the card when the voltage is increased?

It's possible the card calculates the power dissipation. If so, when you increase the voltage the card will underclock to maintain the same power dissipation. You need to go lower in voltage to see if it picks up speed and is stable.

 

[bpanugget]

It's possible the card calculates the power dissipation. If so, when you increase the voltage the card will underclock to maintain the same power dissipation. You need to go lower in voltage to see if it picks up speed and is stable.

OK, I ran it again at 980Mv... the score was the highest I've gotten so far- 21554. I'm gonna stress test it and see if it's stable in the long haul. I also ran it at 1020Mv... the score went down about 300 points.

 

[Alan Alan]

OK, I ran it again at 980Mv... the score was the highest I've gotten so far- 21554. I'm gonna stress test it and see if it's stable in the long haul. I also ran it at 1020Mv... the score went down about 300 points.

Rule of thumb, the hotter something gets the slower it needs to run to be stable. The colder the faster. More voltage produces more power, more power produces more heat. So you should get a better score with 980mv. How low can you go when the computer is already warmed up. Be careful with those stress tests, you might ruin something. Manufacturers do burn in tests under controlled conditions for quality testing. You start running stress tests, you might be sorry you did.

At least now you know why.

 

[KyaraM]

As said above. Modern GPUs, no matter if Nvidia or AMD, are designed to clock as high as possible within their thermal and power limits. For example, I got a refence clock RTX 3070Ti in my system. That means it is rated for clocks of 1770MHz, which means that the vendor only guarantees that clock speed and no more. My card, at stock, runs at around 1930-1950MHz. More about that later.

When the card starts to get close to its set target temperature, it starts to soft-throttle and slowly drop clocks until feels comfy again. If it actually hits or wrse exceeds the target temperature, it will start to hard throttle and drops clocks far more aggressively until it is happy again, or at least maintains the temperature. Also, GPU (and CPU, for that matter) vendors have to make sure that a great variety of GPUs of the same model work roughly the same. A card from the lowest and the highest bin should be within a certain range of each other, else the vendor might run into issues with disgruntled customers and the law, but they will need different voltages to do so. And so, even the good cards run at far higher voltages than they need to. That leads to higher temperatures and also energy draw, which are the limiters of your GPU.

On the 3070Ti mentioned above, I managed to get it run at 70% power draw and 965mV at around the same clock speeds and performance as before; if anything, the hit is mild enough that I don't even feel it. Temperatures dropped by 5-10°C. Benchmark scores are lower in that configuration, but who cares if I don't even feel the performance hit at all? Without the power and temperature limits, it would actually clock higher than 1950MHz. The highest I got was 2075MHz. Then it got unstable. It can hold 1995-2025MHz essentially indefinitely. However, you got to set that manually, that is an overclock already.

 

[Alan Alan]

As said above. Modern GPUs, no matter if Nvidia or AMD, are designed to clock as high as possible within their thermal and power limits. For example, I got a refence clock RTX 3070Ti in my system. That means it is rated for clocks of 1770MHz, which means that the vendor only guarantees that clock speed and no more. My card, at stock, runs at around 1930-1950MHz. More about that later.

When the card starts to get close to its set target temperature, it starts to soft-throttle and slowly drop clocks until feels comfy again. If it actually hits or wrse exceeds the target temperature, it will start to hard throttle and drops clocks far more aggressively until it is happy again, or at least maintains the temperature. Also, GPU (and CPU, for that matter) vendors have to make sure that a great variety of GPUs of the same model work roughly the same. A card from the lowest and the highest bin should be within a certain range of each other, else the vendor might run into issues with disgruntled customers and the law, but they will need different voltages to do so. And so, even the good cards run at far higher voltages than they need to. That leads to higher temperatures and also energy draw, which are the limiters of your GPU.

On the 3070Ti mentioned above, I managed to get it run at 70% power draw and 965mV at around the same clock speeds and performance as before; if anything, the hit is mild enough that I don't even feel it. Temperatures dropped by 5-10°C. Benchmark scores are lower in that configuration, but who cares if I don't even feel the performance hit at all? Without the power and temperature limits, it would actually clock higher than 1950MHz. The highest I got was 2075MHz. Then it got unstable. It can hold 1995-2025MHz essentially indefinitely. However, you got to set that manually, that is an overclock already.

I have the RTX3070, couldn't justify the extra expense on the Ti. I run the video card at X8 anyway. The ssd data pulled off the other X8 lanes is raid 0 with performance similar to Intels VROC. The video card gets the game data as fast as it can be delivered. So there's more to a system then overclocking. I'm not sure I could up the graphic settings even if I did overclock it. Has anyone been able to increase graphic setting with an overclocked video card?

 

[Exploding PSU]

I have to watch this thread, my GPU scores around 17.000 on the same test. Maybe because I set the voltage too high? I never messed with the manual tuning knobs, I just use the automatic settings.

 

[KyaraM]

I have the RTX3070, couldn't justify the extra expense on the Ti. I run the video card at X8 anyway. The ssd data pulled off the other X8 lanes is raid 0 with performance similar to Intels VROC. The video card gets the game data as fast as it can be delivered. So there's more to a system then overclocking. I'm not sure I could up the graphic settings even if I did overclock it. Has anyone been able to increase graphic setting with an overclocked video card?

Oh, the website I bought from sold that particular card at the same price as the cheaper regular 3070s, so I thought, why not? About OC, it's just playing around. I undervolted and power limited my card, it's not overclocking.