Overclocking Gigabyte Radeon HD 7870

[Tums]

Hey guys,

First things first, I own a Gigabyte Radeon HD 7870 factory OC'd to 1100 core clock, and I am using MSi Afterburner to overclock it further.

When I overclock it, i set:
- voltage to 1300 mV, which is max (stock is 1219 mV)
- power limit to +20%
- core clock to 1200 mhz (stock 1100 mhz)
- memory clock to 1300 mhz (stock 1200 mhz)

When I play games like Crysis 2, it will randomly freeze and crash.

I understand this means that I am overclocking it too much, but how is this possible when others have gotten the core clock to run stably at 1250 mhz core, and 1375 memory clocks? I get there are deviations from each board, but to that much degree? My GPU temps never go above 55C as well...

Also, when I run the Uniengine Heaven benchmark, it runs it perfectly fine...

I am so confused, what am I doing wrong here?

 

[blazorthon]

Try lowering voltage. 1.300 is a big step coming from 1.119 and I also suggest leaving memory at stock for now. When overclocking, it's often best not to multi-task with increasing frequencies. Work on one frequency at a time. Once you can stably get the GPU running around 1.2GHz, then try working with memory.

 

[Tums]

wait so i have to do it in increments, and the system slowly adjusts the the overclock each time? so i cant just shoot the core clock to 1200?

 

[bak0n]

you bring core up first, followed by memory. With AMD they used to have an auto overclock feature that would find and set your highest setting to run without crashing. Not sure if they still include it in the CCC.

Also just because others do doesn't mean you can. Each product will have different tolerances and therefore different levels of available overclocking.

 

[blazorthon]

wait so i have to do it in increments, and the system slowly adjusts the the overclock each time? so i cant just shoot the core clock to 1200?

It might not always be necessary, but I find it better to go up in increments and to focus on one frequency at a time.

 

[Cons29]

yes, luck plays a part here. some are lucky to have high oc with little voltage bump. some have so much voltage and yet low on oc.

 

[timil]

If you got it recently its ver likely voltage locked. Also throwing more voltage at a video card doesnt guarantee more core clock, it will just irritate the card. I recommend 1.260v max for 24/7 use on this card, however like i said if you got it recently its possibly voltage locked.

 

[blazorthon]

If OP had a voltage locked card, then I'd expect it to not allow overvoltage rather than not respond to it.

 

[Tums]

If you got it recently its ver likely voltage locked. Also throwing more voltage at a video card doesnt guarantee more core clock, it will just irritate the card. I recommend 1.260v max for 24/7 use on this card, however like i said if you got it recently its possibly voltage locked.

Thanks for reply. How do i check whether or not my gpu is voltage locked or not?

 

[blackcat762]

I have the same card and have not touched the settings (GHz Edition though, it was already at 1200) and I play Crysis 3, everything on High and average 100 FPS. What else are you running (hardware-wise)?

 

[Tums]

I have the same card and have not touched the settings (GHz Edition though, it was already at 1200) and I play Crysis 3, everything on High and average 100 FPS. What else are you running (hardware-wise)?

i5 3570k
asus sabertooth z77
corsair hx750
crucial m4 solid state drive

your core clock was stock 1200 mhz? are you sure that is not your memory clock?

 

[CarolKarine]

I have this card and am stable at 1160 mhz without touching voltage. to be honest, I haven't seen any difference in framerates - I don't think you'll see much difference either. it's a great card as it is stock, the factory OC is one of the best out there.