what is the Limit of overclocking

[DeepakGaur91]

i have nvidia geforce 8400gs 1GB DDR3 its default clock speeds are

Core clock = 567
shader clock = 1340
memory clock = 500
Temperature = 50~52°

i overclocked it with msi afterburner to
Core clock = 640
shader clock = 1512
memory clock = 570
temperature = 60~64°

i do get some improvements in frame rates but i just want to know what is the limit of over-clocking a gpu (specially 8400gs) , a software vtune came with the gpu with that when i change value even little it starts popping up and say lower the setting i didn't see frame rate improvement though but when i use msi i see the improvements but no warning messages, i don't keep the over clocked setting every time i just use them when needed otherwise i just switched back to the default settings

what are the signs when my gpu starts screaming "buy a new one and leave me alone"

 

[faster23rd]

i have nvidia geforce 8400gs 1GB DDR3 its default clock speeds are

Core clock = 567
shader clock = 1340
memory clock = 500
Temperature = 50~52°

i overclocked it with msi afterburner to
Core clock = 640
shader clock = 1512
memory clock = 570
temperature = 60~64°

i do get some improvements in frame rates but i just want to know what is the limit of over-clocking a gpu (specially 8400gs) , a software vtune came with the gpu with that when i change value even little it starts popping up and say lower the setting i didn't see frame rate improvement though but when i use msi i see the improvements but no warning messages, i don't keep the over clocked setting every time i just use them when needed otherwise i just switched back to the default settings

what are the signs when my gpu starts screaming "buy a new one and leave me alone"

The limit of overclocking lies in temperatures and how much the card can take, and since no two card is truly the same, the tolerance for heat varies.

What you want to watch out for are things such as artifacting, it's when a card fails to render an image because it can't operate at the frequency it was overclocked to. Artifacts start to show up and lookl like this:

If you crash to your desktop and/or your computer notifies you that your driver has stopped responding, that could also mean that your card has reached its overclocking limits.

BSODs also happen when you overclock, so watch out for that

 

[C12Friedman]

I started to type out this long involved thing but decided Wiki already covers it with this "Overclocking a GPU will often yield a marked increase in performance in synthetic benchmarks, usually reflected in game performance. It is sometimes possible to see that a graphics card is being pushed beyond its limits before any permanent damage is done by observing on-screen artifacts. Two such discriminated "warning bells" are widely understood: green-flashing, random triangles appearing on the screen usually correspond to overheating problems on the GPU itself, while white, flashing dots appearing randomly (usually in groups) on the screen often mean that the card's RAM is overheating[citation needed]. It is common to run into one of those problems when overclocking graphics cards; both symptoms at the same time usually means that the card is severely pushed beyond its heat, clock rate, or voltage limits (If seen when not overclocked they indicate a faulty card.)" found here http://en.wikipedia.org/wiki/Overclocking
I've never used a graphics card to failure since I will get a new one (or a new system) when I can't get acceptable frame rates any longer on the newer games. As long as I am content with the performance of the graphics card, I keep using it

 

[DeepakGaur91]

"BSODs" means Blue screen ?

should i go forward and increase OC and just watch out for temperature and these warnings

 

[faster23rd]

"BSODs" means Blue screen ?

should i go forward and increase OC and just watch out for temperature and these warnings

Yes, it's an acronym for Blue Scree of Death

Pretty much, just incrementally roll down your frequencies once you see artifacting. BSODs and crashes are rather severe symptoms, so you don;t want to take your computer in their direction.