Help 7870 Tahiti LE overclocking

[Genesius]

I'm new to overclocking so I have few questions to ask.

I'm working on a syste, for a friend.

I've been playing with this card benchmarking it, using OC scanner, kombuster, furmark, cinebench to stress it

The card is voltage locked and only has 'power target'. Not sure what it does.

I left power target alone. I seem to be able to put any value into the card and it will run and run. I check in AMD Overdrive and the overclocks are applied. No issues.

So either, I'm overclocking it wrong, I'm testing it wrong or the card is actually a diamond in the rough.

I also noticed that the Heaven benchmark shows a 1fps difference between the card at 975mhz with 1500mem speed and 1180mhz with 1600mem speed.

Can someone help me out because I don't know what gains to expect or what I'm doing wrong if anything.

Example. Kombuster is running right now, been on 10mins, temps are 74 degrees and gpu load is 100% .
Avg frame rate is 41 at 1080p with AA off,

Kombuster and gpu caps viewer show
Core = 1308
Mem = 1600
VDDC = 1.256

 

[Mgutierrez33]

So you mean to say that memory and core clock can be set as high as the sliders will allow and the card runs with no problems? If that's the case the good on you... if you are doing so WITHOUT changing the power target as well, then WOW O_O. The power target slider allows you to adjust what percentage of the power draw of the card is being utilized (so in a sense it IS kind of adjusting voltages, only the card does so on it's own).

For instance, if the card has a 300W current draw under load, then by increasing the power target (or power limit depending on the software) to 110%, it can draw as much as 330W to achieve stability at the given clock speeds. The thing with this procedure is that you can't manually go in and adjust the specific voltages that are being delivered to the video card, so it's a more roundabout method that most newer video cards are adapting since it's a bit safer.

 

[Master&Puppet]

I'd use Unigine Heaven 4.0 to stress test with and then some games - the other furmark based ones no longer work very well in my opinion.

 

[Genesius]

Yeah i can put the slide to pretty much watever, the only crash i had was when i turned the power adjust up.

im currently running 1600 on memory and 1180 on clock, but it will run 1300 clock, but it gets a bit hot with only one fan.

I thought it was too good to be true or i was doing soimething wrong.

I use heaven to benchmark and ive left it running for a few hours as well. i used the new 3DMark 2013 as well and i just cant make it crash.

the thing is the rig is for my friend who isnt really interested in pushing the stuff that hard, he wants a quiet, cool temp rig.

also the fps in heaven benchmark doesnt really change. i gained 2 fps over stock with the 1180 OC is that normal for GPU's?

 

[Mgutierrez33]

Unigine I don't think runs particularly well with AMD video cards because it tends to favor PhysX. A better test of functionality and stability is really 3DMark, since if anything is going to fail, that's where it'll fail or reveal it's weaknesses.

 

[SeekaX]

Unigine I don't think runs particularly well with AMD video cards because it tends to favor PhysX. A better test of functionality and stability is really 3DMark, since if anything is going to fail, that's where it'll fail or reveal it's weaknesses.

unigine usually runs better on AMD

 

[Genesius]

So I think his card may be a diamond card, but can someone confirm that applying an overclock to a gpu should only gain modest increases in fps? Or is my lack of fps increase a sign that I'm doing something incorrect.

 

[SeekaX]

So I think his card may be a diamond card, but can someone confirm that applying an overclock to a gpu should only gain modest increases in fps? Or is my lack of fps increase a sign that I'm doing something incorrect.

the fps should increase a bit, but don't expect things like 50% fps increase.
a normal fps increase would be in unigine 3 extreme settings with a 7950 from 38 fps on stock to 44 fps with a decent overclock. don't know if you'd consider that modest.

 

[Mgutierrez33]

unigine usually runs better on AMD

does it? thought it was the other way around... I do that sometimes x-(

 

[Genesius]

the fps should increase a bit, but don't expect things like 50% fps increase.
a normal fps increase would be in unigine 3 extreme settings with a 7950 from 38 fps on stock to 44 fps with a decent overclock. don't know if you'd consider that modest.

Ok we'll that's 6fps. So I think with the mild overclock that I've applied to this card 2-3 fps should be right. I have tesserlasion on high, 1920x1080 AA on 4 and everything else on ultra.

 

[alienware]

does it? thought it was the other way around... I do that sometimes x-(

It certainly did on all versions up to 3.0.

It may have changed slightly in 4 but it definitely doesn't use Physx.

Even when a benchmark does now you don't gain anything for it. AMD users used to criticise 3Dmark Vantage for giving extra CPU points for the Physx so they removed it.