Downclocking 7970 ghz?

In3rt1a · Jan 24, 2014

Hey guys, I tried doing a google search for this, but couldn't come up with anything, so I thought I'd ask some more experienced overclockers than myself. I have a sapphire 7970 ghz edition clocked at the stock 1050 mghz, and am trying to create a custom fan curve to make things as quiet as possible. I have monitored my fan speeds while running heaven and determined that anything above 50% is clearly audible, so is it a good idea to downclock my gpu? Thanks all

ShadyHamster · Jan 24, 2014

Underclocking is fine how ever just remember it's going to impact performance too.
I would suggest try undervolting first, that should effect the temps more then changing the clock speeds, or you could do a combo of both.
How far you will be able to underclock will depend on the quality of the silicone, how lucky or unlucky you got in the silicone lottery basically.

cuecuemore · Jan 24, 2014

If you're not going to miss the performance then go ahead. Are you asking if it's safe? Any underclocking will be safe. What are your temperatures? You may be able to get away with 50% fans at stock clocks.

In3rt1a · Jan 24, 2014

I don't think I will have any performance issues, i'm running @ 1080p and have had fluid fps thus far. My temps are currently getting upwards of 75c after running heaven for 5 minutes with my custom fan curve, so that's why I'm considering underclocking. I am not too concerned about safety as much as if it will help my temps. I would rather not touch voltage though, cause isn't that where you can begin screwing things up?
Edit: I'm also thinking about working on some cable management tomorrow, I did a pretty horrible job when I put my pc together.

cuecuemore · Jan 24, 2014

You can underclock, but undervolting will drop temps a lot faster. But you don't need to do anything about your temps, at 75C you still have a lot of headroom.

ShadyHamster · Jan 24, 2014

I've never come across someone screwing something up while undervolting, but i'm sure someone has so don't quote me on that.
Undervolting works the same way as if you were overclocking/volting, simply decrease the volts 1 step then test if the card is still stable, continue until it becomes unstable then increase the volts by 1 step to regain stability.
You should be able to underclock to what ever you want (at least on the core, the mem might be different) and it won't effect stability it will just lower your fps.

In3rt1a · Jan 24, 2014

Okay, thanks, that's what I was hoping to hear. How will I be able to tell when my card is unstable? Artifacting?

In3rt1a · Jan 24, 2014

cuecuemore :

The thing is, I stopped heaven when I got above 75c because I thought those temps were dangerous. How hot can I let my graphics card get?

cuecuemore · Jan 24, 2014

75C is actually icy for a 7970; 95% of the folks here will tell you otherwise, but they're not serious users. There is no official data on TJM out there, but in a conversation with an actual Radeon engineer I found out that the max for my 7970s was 100C. I keep them below 90 just to be completely safe, but I've been running them 24/7 for 2 years in the high 80s without any issue.

In3rt1a · Jan 24, 2014

Thanks to both of you guys for helping me out. For some reason, sapphire trixx wasn't letting me adjust my voltage, so I lowered my core clock 50 mghz and now everything runs cool and quiet, and I still have great performance.

cuecuemore · Jan 24, 2014

Voltage is locked on the majority of 7970s, at least the GHz editions. Mine are both factory OC originals. But congrats on achieving what you wanted!

porze13 · Mar 28, 2014

ShadyHamster :

hi have some heating issue to with my HIS 7970 Reference mode and would like to know how to do the voltage thing that u guys r talking about. what program would i need to use? (i have MSI afterburner would that work) and how would u know if its stable or unstable?

whenever i play games like battlefield 3 or 4 my temperature would reach 85-95c

thank you hope u guys can help

In3rt1a · Mar 28, 2014

In sapphire trixx, there is a setting called "vddc" which is voltage. There should be an option to turn vddc up or down in afterburner on the same screen where you can adjust clock speeds. If that doesn't work, uninstall afterburner and use sapphire trixx. That is what I use. To test stability, just run a benchmarking software like Heaven and keep an eye out for artifacting, or the more dramatic indicator, crashing. Also, undervolt in slow increments.

porze13 · Mar 28, 2014

In3rt1a :

thanks for replying back.
so if i dont see any artifacting then my card should be fine?

btw at what temperature will the 7970 be at risk?

In3rt1a · Mar 28, 2014

Yep, if there are no signs of instability (artifacting or crashing) then your card is stable. Like cuecuemore said, 100c is the absolute max for 7970s, but 90c is probably the max safe temperature.

porze13 · Mar 28, 2014

In3rt1a :

Sweet thank you i very appreciate it. i just got my gpu to run bf4 at 73C its way cooler then 95C thank you so much!

In3rt1a · Mar 28, 2014

Great, that's a nice safe temp, glad I could help

Downclocking 7970 ghz?

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Distinguished

Honorable

Distinguished

Honorable

Distinguished

Honorable

Distinguished

Share this page