Video card, Cable or Monitor?

Yesterday I started noticing small (1 or 2 pixel sized) blinking red dots appearing randomly in videos and images on my external monitor ( iiyama 22”). Those dots move with the video/image when I move or scroll the video player or image viewer. I have seen similar type of artifacts before on dying desktop video cards and on cards overclocked too much, therefore I initially thought that this is a video RAM problem (since my 8400M GS was never over clocked). But so far, these artifacts only come on the external monitor at 1680x1050 when using a HDMI to DVI ( Monster Ultra 600 HDMI to DVI) cable. I don’t see anything if I use either the built-in notebook LCD display at 1280x800, external display at a lower resolution or external display over standard VGA cable (even at 1680x1050).

I was using the DVI cable for about two weeks now; but only started seeing these artifacts yesterday. And I am absolutely sure they weren’t there before. What do you guys think? I will test this further by connecting the notebook to different monitors, using different cables (but it’ll be very hard to find another HDMI to DVI cable unless I purchase one , could it be the cable I hardly think so, considering the way these artifacts behave..... ).

Update : I didn’t install any new programs or drivers immediately before this started happening; however I used the notebook more than I usually do, over the past few days. And I think I left it ON over night for one or two days. Room temperature is around or below 20C and I didn't notice the GPU or the CPU temp rising over 60C while I was using it (i8kFanGUI - monitor mode only/no fan control)

 

Bump and update,

Selecting Power saver mode in Vista improves things slightly (fewer red dots), but still they are there. I guess this means it is a hardware problem of the gfx card afterall . I checked core / mem speeds with GPUZ when running under power saver mode and performance/balanced modes, speeds are 275/300 and 400/600 respectively.

 

I guess not.. If it be a Vram problem.. then it should be come with the analog signal that they send out..(VGA or in laptop LCD).. I have probably thinking that thats the wire or the connector is malfunctioning.. and the noise detection system of your monitor putting some gurbage value(Red pixel in your case)..

 

As the dots move with the image when you move the window around, you can completely rule out the cable or connector as the problem. If it were the cable or connector, the dots would be static and not be affected by scrolling at all.

Having said that, until I read the part where you said they move with scrolling, I suspected a connection issue. The only other options are (in order of likelihood, most likely first): -

1) Failing video RAM.
2) Failing video decoder subsystem (hardware).
3) Failing power supply (possibly a local failure of on-board power regulator or voltage converter).
4) Failing GPU (this would cause other symptoms, including complete system hangs).
5) Software problem.

I'd usually list 'Software problem' higher, but if you're correct when you say no software changes have taken place, it becomes highly unlikely as a cause.