Help please with reference 5850 overclocking

[Liampope]

Hi folks,

Never really overclocked a GPU much before, but my reference (OEM so not even a sticker on it) 5850 seems willing so I'd like to set it up properly and would appreciate some advice. Currently has stock bios.

I started out playing around with ATI GPU clock tool and found I could furmark at 875/1200. AMD GPU clock tool appears to automatically raise the voltage to 1.088 when doing this from a default of 1.0. Though it could run furmark in a window, Crysis crashed with these settings and there's no option for higher volts.

I then installed MSI afterburner to have a play with that. I found the graphs in afterburner tally with what I set in GPU clock tool. The frequency sliders in afterburner are limited to 775/1125 which is no good but I found I could override them with GPU clock tool. Afterburner gives higher voltage adjustment so I put 1.2V on then went back to afterburner and set 900/1200. Then back again to afterburner to take back control of fanspeed because changing clocks in GPU clock tool sets fans back to default. So afterburner now reads 900/1200 @1.2V (including on the clock sliders even though if I actually try to use them they dont go up that high!). I can then furmark or play Crysis fine at those settings and good temps - high 60s with 50% fan if I recall.

I'm sure she can give even more, but the current faffing about with two programs every time I want to OC the card is a little annoying.

I'm aware the thing to do is bios mod my card, right? In fact I thought I would have to bios mod it to get voltage adjustment working, but I seem to be able to do that already?? Is that not right?

If I flash it with an msi bios will I just be able to do everything in afterburner - i.e. the clock sliders will go up high enough, instead of having to use GPU clock tool to set the clocks? That would basically be awesome. If so what bios would I use?

Any advice appreciated. Cheers,

Liam

 

[MoodyB]

Open Afterburner's config and change 'enable unofficial overclocking' to '1'.

That should remove the slider limits.

 

[el Kuarlos]

I flashed with asus bios, cant remember why, might have been convenience.

Mine was slightly after launch, nov i think. It is rock solid at 875/1250 at stock, the core wont handle more without more volts, and i dont need to add them as of yet. The memory seems to be ok at that level, and even 1275, but there are suggestions the memory will work at higher, but produces errors and as such 1250 is as high as the normal bloke should go.

If it is limiting you, flash msi bios, attach a vf3000, which i personally vouch for, and go for 1000+ with more voltage.

As per being a gpu oc noob, it is dead simple, not like processors.

Max the clocks until it starts crashing/artifacting, then. More jigawatts equals more shiny. Too much jigawatts equals broken card.

 

[Liampope]

Cheers guys

I enabled the unofficial overclocking and now seem to be sorted using afterburner alone. So what's all that bios flashing business I read about? Seems like I dont need to do it??

Sitting at 900/1200 comfortably and I will see how high it can go and find some optimal settings.

 

[JTrickle]

I started out playing around with ATI GPU clock tool and found I could furmark at 875/1200. AMD GPU clock tool appears to automatically raise the voltage to 1.088 when doing this from a default of 1.0. Though it could run furmark in a window, Crysis crashed with these settings and there's no option for higher volts.

The default voltage on 5850s is 1.088v. At least it is on mine. I can use Afterburner to adjust it downwards to 1.0v. And at 175/300 desktop revs, its around .95v At 1.0v (I was running underclocked before I passive watercooled mine) I could only get 575mhz stable, not quite 600.

On threads around release time last year, people were reporting top overclocks without voltage adjustment of between 850 and 875. So your experience sounds normal. If you can adjust your voltage higher in Afterburner, then thats fine

 

[el Kuarlos]

Sitting at 900/1200 comfortably

You should take the memory to 1250, keep an eye on temps, if you have to notch back on the core to do this I would say its worth it; performance gains are quite nice.

 

[Liampope]

Thanks for the info. Yeah I realise now the 1.088 is the default load/3D voltage. I'm not sure why GPU clock tool reports 1.0 as default, because as you say the idle/2D voltage actually is 0.95 (as reported by afterburner) with 175/300 clocks.

I'm just curious as to why some needed to bios mod with an asus or msi bios? Oh well never mind.

 

[Liampope]

Cool - crysis session @ 950/1250 1.2V 65 deg steady (albeit at a noisy 75% fan - need to sort out a proper custom profile I think). Anyone know what are voltage and temp spec limits?

@ el Kuarlos: you're right - this seems much easier than CPU OCing

More more push it more!!

 

[hash70]

try msi mate