Overclocking G1 Gaming GTX 980 SLI - Without Changing Voltage

[Ransome]

My specs:
Gigabyte G1 Gaming GTX 980 SLI.
Core i5-3570k (OC to @ 4.2 GHz, auto voltage).
16 GB of G.Skill Ripjaw-X DDR3 1600Mhz (x.m.p profile)
Asus Sabertooth Z77 Motherboard
SSD 256GB Crucial M4.
HD Western Digital Black 2TB
PSU: Corsair 850AX Gold
CPU Cooler: Noctua NH-D14
Case: Corsair CC600T Graphite White Special Edition
Win 8.1 64bit. Pro
Monitor: Asus ROG SWIFT PG278Q 2560 x 1440p 144 MHz
Secondary Screen: 55" TV: Samsung UA55D6400 TV1080p 60 MHz (TV Connected via Pioneer VSX-823-K AV Receiver)

I am considering overclocking my two Gigabyte GTX 980s G1s.
Both GPUs are rather new (7m, 1m old).
So I want to find a solid, stable and safe OC without increasing the voltage levels.
I looked it up, and found this guide:
http://www.guru3d.com/articles_pages/gigabyte_geforce_gtx_980_g1_gaming_review,26.html
As you can see the editor did add some extra Voltage.

I want to find a similar OC without adding any voltage to stay safe for long term use.

This is what I experimented now:


I tried playing some The Witcher 3 @ 1440p and mostly Ultra settings:
The game ran fine for a few hours yesterday, today it froze my entire PC but not sure if it's OC related at all.
My temps were very cool, around the 60s, and around 68-71c when over 95% load for a long time.
But the freeze still worries me.
Maybe I went overboard with the memory clock?
I know some people add +170 MHz Core Clock without adding voltage, but I don't know about Memory clocks.

Can/should I OC any further? like +500MHz memory or +170MHz Core? Or should I actually go down a notch or not OC at all?
Thanks in advance.

 

[Ransome]

EDIT: Thinking about trying +150 MHz Core, +300/350 MHz Memory, Power Target 122%, Temp Target 79c. No extra volt. Does it sound reasonable and stable?

 

[krells]

It is worth a shot. Why don't you want to touch the voltage? All you can do is test it and watch for artifacts. As far as clock speed goes on average 1550mhz boost clock seems to be the upper end for most cards.

 

[Ransome]

It is worth a shot. Why don't you want to touch the voltage? All you can do is test it and watch for artifacts. As far as clock speed goes on average 1550mhz boost clock seems to be the upper end for most cards.

About the boost clock, thanks I will try not to cross this bar.

About the voltages, the guide I posted above suggested:
Temp Target 80 Degrees C
GPU clock +155 MHz
Power limiter 122%
Mem clock +500 MHz
Volatge + 87Mv
FAN RPM default

As you can see they added+87 mV.
+87 mV is the maximum Voltage you can add by using MSI or Precision X.
So basically they cranked the extra voltage slider all the way up.
I am rather new to OC, I just thought that not increasing voltage might be safer..
I also want to avoid increasing the heat too much.
These are 2 strong cards, and they cost me a lot. So last thing I want is to damage a excellent GPU for the sake of some small performance gain.

However if adding voltage, like Guru3D have done, will actually make my OC safer, stronger and more stable - than I don't see why not.

What do you think? Which values I should test?
Or should I simply copy the exact overclock Guru3D did?

 

[Sergeant_Sneaky]

Adding +87mv will only add 25mv as they are limited to this. The voltage should make a higher overclock more stable and the voltage limit is set by Nvidia, so as long as your temps are okay, it should be fine.

 

[Ransome]

Adding +87mv will only add 25mv as they are limited to this. The voltage should make a higher overclock more stable and the voltage limit is set by Nvidia, so as long as your temps are okay, it should be fine.

So you say that even if I add +87mV it will only count as 25mV?
Why not simply add 25mV and that's it? And how come Guru3D added +87mV anyway, if they knew it won't count?
Please explain this further.

Give me an example of normal OC temps with SLI for GTX 980s.

Furthermore, can you recommend certain numbers for a safe long term overclock? (core,memory,power,voltage).
Thank you.

 

[Sergeant_Sneaky]

Adding +87mv will only add 25mv as they are limited to this. The voltage should make a higher overclock more stable and the voltage limit is set by Nvidia, so as long as your temps are okay, it should be fine.

So you say that even if I add +87mV it will only count as 25mV?
Why not simply add 25mV and that's it? And how come Guru3D added +87mV anyway, if they knew it won't count?
Please explain this further.

Give me an example of normal OC temps with SLI for GTX 980s.

Furthermore, can you recommend certain numbers for a safe long term overclock? (core,memory,power,voltage).
Thank you.

Yes, it will only do 25mv, I think you can get to +87 on a custom bios. Most people put it to +87mv even knowing it only does 25mv. I'm not sure about SLI temps, but you want to keep it under 80c if possible.
There's not really a "safe" limit to anything as the voltage is locked and if its stable and running cool, it is considered safe.

 

[krells]

It is worth a shot. Why don't you want to touch the voltage? All you can do is test it and watch for artifacts. As far as clock speed goes on average 1550mhz boost clock seems to be the upper end for most cards.

About the boost clock, thanks I will try not to cross this bar.

About the voltages, the guide I posted above suggested:
Temp Target 80 Degrees C
GPU clock +155 MHz
Power limiter 122%
Mem clock +500 MHz
Volatge + 87Mv
FAN RPM default

As you can see they added+87 mV.
+87 mV is the maximum Voltage you can add by using MSI or Precision X.
So basically they cranked the extra voltage slider all the way up.
I am rather new to OC, I just thought that not increasing voltage might be safer..
I also want to avoid increasing the heat too much.
These are 2 strong cards, and they cost me a lot. So last thing I want is to damage a excellent GPU for the sake of some small performance gain.

However if adding voltage, like Guru3D have done, will actually make my OC safer, stronger and more stable - than I don't see why not.

What do you think? Which values I should test?
Or should I simply copy the exact overclock Guru3D did?

The voltage adjustment won't damage your card. Try running your settings you listed with +87 voltage. For me I go from 1504 boost clock to 1530.

 

[Ransome]

It is worth a shot. Why don't you want to touch the voltage? All you can do is test it and watch for artifacts. As far as clock speed goes on average 1550mhz boost clock seems to be the upper end for most cards.

About the boost clock, thanks I will try not to cross this bar.

About the voltages, the guide I posted above suggested:
Temp Target 80 Degrees C
GPU clock +155 MHz
Power limiter 122%
Mem clock +500 MHz
Volatge + 87Mv
FAN RPM default

As you can see they added+87 mV.
+87 mV is the maximum Voltage you can add by using MSI or Precision X.
So basically they cranked the extra voltage slider all the way up.
I am rather new to OC, I just thought that not increasing voltage might be safer..
I also want to avoid increasing the heat too much.
These are 2 strong cards, and they cost me a lot. So last thing I want is to damage a excellent GPU for the sake of some small performance gain.

However if adding voltage, like Guru3D have done, will actually make my OC safer, stronger and more stable - than I don't see why not.

What do you think? Which values I should test?
Or should I simply copy the exact overclock Guru3D did?

The voltage adjustment won't damage your card. Try running your settings you listed with +87 voltage. For me I go from 1504 boost clock to 1530.

Thank you all for your patience and help.
How much +MHz did you add to your Core clock? Sounds like you added over 160MHz. Isn't that too much?
What about the Memory clock? Have you changed it?

About the voltage, I just wonder why not simply add +25mV to be safe - or not at all, if possible.
Is there a risk of OCing without adding extra voltage? Or perhaps OC without adding voltage can cause bottle-neck?

Finally I try to make my mind whether I should "copy" Guru3D's OC (155core,500mem,87mV) or make it lower say +400mem, +150core.

 

[Sergeant_Sneaky]

It is worth a shot. Why don't you want to touch the voltage? All you can do is test it and watch for artifacts. As far as clock speed goes on average 1550mhz boost clock seems to be the upper end for most cards.

About the boost clock, thanks I will try not to cross this bar.

About the voltages, the guide I posted above suggested:
Temp Target 80 Degrees C
GPU clock +155 MHz
Power limiter 122%
Mem clock +500 MHz
Volatge + 87Mv
FAN RPM default

As you can see they added+87 mV.
+87 mV is the maximum Voltage you can add by using MSI or Precision X.
So basically they cranked the extra voltage slider all the way up.
I am rather new to OC, I just thought that not increasing voltage might be safer..
I also want to avoid increasing the heat too much.
These are 2 strong cards, and they cost me a lot. So last thing I want is to damage a excellent GPU for the sake of some small performance gain.

However if adding voltage, like Guru3D have done, will actually make my OC safer, stronger and more stable - than I don't see why not.

What do you think? Which values I should test?
Or should I simply copy the exact overclock Guru3D did?

The voltage adjustment won't damage your card. Try running your settings you listed with +87 voltage. For me I go from 1504 boost clock to 1530.

Thank you all for your patience and help.
How much +MHz did you add to your Core clock? Sounds like you added over 160MHz. Isn't that too much?
What about the Memory clock? Have you changed it?

About the voltage, I just wonder why not simply add +25mV to be safe - or not at all, if possible.
Is there a risk of OCing without adding extra voltage? Or perhaps OC without adding voltage can cause bottle-neck?

Finally I try to make my mind whether I should "copy" Guru3D's OC (155core,500mem,87mV) or make it lower say +400mem, +150core.

You can just add 25mv if you'd like. There is no risk to overclocking without adding voltage, you may just get a slightly lower overclock. Don't jump to other people's configs, experiment yourself, all chips are different, up the core in 10s or 15s at a time and check stability.

 

[Ransome]

Thanks for the advice.
I tried an OC like the one I listed above but I was unhappy with the temperatures - as it increased my temps from 69-71c at full load - to 74-76c.
I also tried similar OC with no extra voltage - but encountered freezing.

So after some trail and error, I think I found a stable, relatively cool Overclock - that should hopefully provide a solid Performance boost:

Temp Target 79 Degrees C
GPU clock +155 MHz
Mem clock +300 MHz
Power limiter 122%
Volatge + 25Mv
FAN RPM default

With this I managed to stay at 70-72c - at full gpu load. Which is pretty great. Core clocks go up to 1522MHz or more, and memory to 3802MHz.
I will have to test this for a long gaming session and report, hopefully it will remain stable.

Can I ask a question, why does the Guru3D guide and others - count Memory clock doubled - saying GTX 980 is 7000MHz.
While MSI/Precision show only half of it: 3500
And GPUz show 1/4 ! = 1750 MHz.

Why do they all use different measurements? It's awfully confusing.

UPDATE: about the OC, seem to produce a few bloom/lighting related artifacts like rainbow colored squares appearing for split seconds. Will tone it down and test.

 

[Sergeant_Sneaky]

Thanks for the advice.
I tried an OC like the one I listed above but I was unhappy with the temperatures - as it increased my temps from 69-71c at full load - to 74-76c.
I also tried similar OC with no extra voltage - but encountered freezing.

So after some trail and error, I think I found a stable, relatively cool Overclock - that should hopefully provide a solid Performance boost:

Temp Target 79 Degrees C
GPU clock +155 MHz
Mem clock +300 MHz
Power limiter 122%
Volatge + 25Mv
FAN RPM default

With this I managed to stay at 70-72c - at full gpu load. Which is pretty great. Core clocks go up to 1522MHz or more, and memory to 3802MHz.
I will have to test this for a long gaming session and report, hopefully it will remain stable.

Can I ask a question, why does the Guru3D guide and others - count Memory clock doubled - saying GTX 980 is 7000MHz.
While MSI/Precision show only half of it: 3500
And GPUz show 1/4 ! = 1750 MHz.

Why do they all use different measurements? It's awfully confusing.

UPDATE: about the OC, seem to produce a few bloom/lighting related artifacts like rainbow colored squares appearing for split seconds. Will tone it down and test.

Nice overclock Remember you can always raise the fan speed to get the temps down so you can oc higher
About the different measurements, I don't know, it's silly, I think the correct one is 3500Mhz x 2, as gpus double it I believe? I've had issues with this before, someone asked a question and said they're VRAM clock speed and I had to ask what program is showing this because they all show different.