The official Graphics Card Overclocking Thread

Overclocking Graphics cards perhaps isn't as obvious as overclocking processors, but in some cases can provide noticeable performance boosts. This thread should be good to help people (including myself) gain experience in this field, and allow us to gain a good grasp of what overclocks well, what doesn't, and any particular trends that get discovered.
So, anybody with any stories to share? The first thing I have noticed, which should perhaps be quite obvious is that the HD4870X2 I have is nowhere near as good an overclocker as the solo HD4870 (512MB) - I think this is for two reasons - firstly because having two GPUs on one board, extra heat, the fact that crossfire is running, and so on and so forth will place more stress on them, and secondly, the memory used is high density, twice the amount of memory per chip as the ones used on the solo card, it stands to reason that for the same reason 2GB DDR modules don't overclock as well as 1GB ones, high density graphics memory should behave similarly.

 

One thing I noticed is that although CCC let's me max out both the core and memory frequencies, and tells me after the "test" that they are good, I still experience studdering. After I lowered my memory freq. slightly the problem went away. I'd post my numbers but I am on my laptop at the moment. I don't even know how much of a difference stock vs overclocking helps me. I need to pull out some 3D Mark06 and do some benchmarking.

 

Catalyst's test is ridiculous, for the HD4870 and X2 it has never failed any overclock, even one so unstable that the instant you open a 3D application your PC reboots. It used to be a reasonably valid test, no more it seems.

 

I have a Nvidida GeForce 8500 GT. Can anyone help me OC this? I have no idea how to do this. Thanks

 

Ok, first of all you will need a program like nTune.

 

What do I do after installing nTune?

 

You will be presented with various tools. Find the overclocking tool and you can see two main speeds, the core speed and the memory speed. Try overclocking the core first (slowly, graphics cards don't overclock as far as CPUs) and run games tests to see if the card can handle it - if it can't, it will crash. When you reboot, reduce the speed and try again. Do the same for memory, but instead of getting crashes, you are on the look out for graphical corruption, typically wrongly coloured sparkly bits (yellow or red), wrongly coloured whole blocks (grey walls randomly turning black or see through) and odd triangles showing up. Generally, if it's a problem, it won't be hard to spot. Memory typically overclocks better than the core.

 

First use the Nvidia Smart Doctor program it will allow you to quickly check the max clocks. Use Rivatuner once you fgure out stable clocks it's better.

Don't expect to get a huge boost out of that card. I have the same one and rarely notice a difference when it is overclocked.

 

I have not tried it yet. Is it worth the try though?

 

The 8500GT can actually be overclocked quite far from what I've heard, but it's such a slow card to begin with, you're sort of turning a VW Beetle into a Mini, rather than getting anything grand out of it.
I don't tend to find auto clock finding programs very accurate at all though, I'll warn you of that now.

 

Could overclocking a graphics card, memory, or processor damage my computer? It is running fine right now. I don't really want to risk that if I don't need it? What are the advantages of overclocking?

 

Not just by changing the clocks. You only cause damages by increasing the voltages, which is safe to an extent with CPUs, safe to a lesser extent with memory, and pretty much always dangerous with graphics cards.

 

Okay thanks. I think I will overclock later when I feel like it is needed. What are the advantages of overclocking the CPU, RAM, and Graphics Card? What can that advantage be used for?

 

CPU-bound programs run faster, such as DVD rips, file compression, and so on. It also helps some games significantly.

 

AS you know from our previous discussion, I have a Dell Dimension 2400. so I can not overclock my system. Is it still possible for me to overclock the graphics card and RAM? What are the advantages of overclocking RAM and Graphics Cards? What are the advantages used for?

 

The Dell 2400 uses integrated graphics, which can't be overclocked. In any case, integrated graphics are so weak you would need them to be more than ten times as powerful to play modern games, and that still wouldn't include crysis. Considering graphics overclocks very rarely net more than a 15% performance boost, it'd be a lost cause even if you could.

 

I put a GeForce 8500 in my Dell Dimension. I guess I am not doing that. Not worth the risk for this, or any graphics card. What are the advantages of overclocking RAM?

 

Sorry, forgot about that. You can overclock your graphics card if you like, (though you will still get mediocre graphics performance as it's only an 8500). You can't overclock the RAM in your system as Dells do not allow that. Overclocking RAM is rarely useful other than for certain video editing programs, it's main function is to allow you to overclock your CPU further.

 

So later on when I build my new computer, should I overclock my RAM before overclocking my CPU?

 

The two go hand in hand.