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Maxwell overclocking and actual voltage

Guest2

Guest2

Guest2

Soldato
Joined
6 May 2009
Posts
20,384
I have been doing some testing with my 980Ti using a multimeter and it appears Afterburner and Precision X overvoltage does nothing up to a point.

With Afterburner installed and no additional voltage applied at load the multimeter would read 1232mV but quickly stepped down to 1218mV. Adding +17 it would raise to 1232mV and hold the max boost clock (1405mhz on my card)
Adding +50mV however, it would stay at 1232mV. Even flashing the bios to 1250mV it seemed to stay locked at 1232 unless I was doing something wrong.

Using Precision overboost however does actually increase voltage. Precision reading/Multimeter reading

1225/1254 (5.3.10)
1231/1250 (5.3.11)
1262/1295 (5.3.10)
1268/1300 (5.3.10)
1275/1307 (5.3.10)
1281/1312 (5.3.10)
1300/1332 (5.3.10)

I did notice that raising the voltage to 1300 perfcap reason in GPUZ changed from VRel/VOP to Pwr (limited by power) but it then throttled the core clocks as I guess power tabled need modification to match the high volts

XYu2Lpq.png


There was a slight voltage difference between versions too see brackets

In short, if you want to add some extra volts, don't bother with overvoltage because it doesnt do anything beyond 1232mV, use Precision overboost. Also, ignore the VDDC reported in GPUZ and software because its incorrect

I may look into bios voltages but i've had enough of removing drivers, software and flashing my card for the time being
 
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Some points to consider:

- Your DMM will have a margin of error.
- Applied voltage may change based on Maxwell architecture algorithms completely out of your control
- Are measurements taken in a controlled environment (same load, same time, same environment variables)
- Are you taking multiple readings at any given setting and averaging out the result or just taking single snapshots
 
The voltages are pinned to the boost clock, so as the clock speed fluctuates the voltage will too.

You'll need to edit the voltage table in your BIOS to get around this.

I found with my 980 adding voltage is a bad thing. All it does is increase the rate I reach the power limit, does nothing for max clocks.

With stock voltage and upping the power limit I can reach the max stable clocks shown in my sig.
 
Calibrated? I just tested it on an AA battery.
Gpuz load each time was used
3 readings and averaged out
The max boost clock by default is around 1580mhz howver it would boost to 1405mhz out the box.

Applying say +17mV, means multimeter the multimeter reading stays at 1232 cand the card sticks at 14005mhz. My main point however was that applying +50mV it also stays locked at 1232mV
 
Guest2 said:
Thanks, ill try these. Do power tables need modifying to to allow more power for increased voltages?
Click to expand...

Np :) Try the voltage first. If you're hitting the power limit with the higher voltage you can adjust the power table to prevent throttling. This is where ASIC quality comes into play. The higher the quality the less likely you are to reach the power limit.

A run of Firestrike Extreme will quickly show you if you are limited.

As I said earlier though you shouldn't have to adjust voltage at all, boost 2.0 is a bit backwards in that sense. I have set my CLK 67-74 to stock voltage to stop it adding more than it needs.
 
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Thats what i don't get. Clk states 64-74 the max is something like 1281mV, shouldnt it ue the maxes if required by default? Or is it locked by the first few tables in voltage table (the ones you oictured above)
 
I posed my rom on overclock.net and someone 'unlcoked' my rom, but made no modifications to it. This is pictures on the left image whilst my default one is on the right.
Anyone know what the two voltage tables are that have appeared and what this unlocking provides?

The stock and modded above do not appear to have been unlocked

PWsTfCY.png


I have set those voltage table settings and now just see VRel and 1.2120V at full load. VOp no longer shows

Multimeter reading is now showing 1.240V
 
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All that's doing is disabling boost by locking your voltage to 1212.5mV.

I'm not sure why they've used the word 'unlocked'.

You'll need to make sure CLK 74 is 1212.5mV min and max if you want to lock the card to the max boost clock.
 
The P05 profile is idle to adaptive boost and power state for desktop video and software. You can see the first CLK entry 825.0mV - 825.0mV corresponds to lowest bin on the boost table.

I'd take a guess at 1200.0mV being the memory voltage if it's fixed.
 
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