9800GT Graphics card problem

Hello, I acquired of a PC there is now 1 month with the following configuration:

Motherboard MSI P6NGM-L
Processor Intel Core2Quad Q6600
3Go of memory DDR2
Graphics card 9800GT with 512Mo
Engraver of DVD x20
DD 500Go
power supply 520W

This PC is mainly dedicated to the play.
All went for mine until this problem which I will expose you.

Here while played (crysis for the occasion) I started has to see small square sinks to appear has different place from the forming screen of the block. Then at the end of some minute the image solidifies and I am obliged to leave the plays “with hard”. I test on another plays (Far Cry 2) the same thing occurs. I thus put the drivers of my up to date charts and the bug disappeared during 1 weeks

But here that today the same phenomenon occurred. I also noted that on certain play using less “graphic power” (for example left 4 dead) this problem does not occur. I checked the Temperature of my graphics card after having played quoted plays above and that it was not alarming.
I thought that could come from my monitor which is not very young (IIyama HM903DT) but I cannot too what make.

I will like to know from where this problem can come and how to solve it.

Thank you for your nearest answers

hello,
That can be the Graphics card which has engineering problems where which are badly fed. It goes up has how much in full the graphics card? According to the image, that resembles has an overheating of the graphics card.

I do not even exceed the 40C° while I play crysis: S and yet the bug was present. I noticed that it was especially on crysis that the bug appeared and that it reproduced then on the other plays. If I play another play has that crysis without to have played before that Ci functions there perfectly.

The mark of the power supply, There are the tensions of not marked above ? because I think that it is the power supply which is in twists.

Here is the label:
Voltage 230V Current 5A Frequency 47-63Hz

there may be a tool making it possible to know the power of power supply which the Graphics card receives? Of this fact I will be able to know if this power supply is insufficient.