PC whistles after installing 9800 GTX

[goatape]

Hello,

I just bought a new graphics card, is "TWINTECH GeForce 9800 GTX + (512 MB DDR3, PCI-E)". I have not checked if this graphics card is compatible with my PC config. . And what had happened happen ... After installing the graphics card, connect the PCI Express GC 6-pin to my mobo (I hope that I connected where it was), I turn on my PC and a sound is strident and acute sounded. Indeed, my cpu has 350 W and the CG requires a minimum of 400 W. So I will buy a more powerful food. But:

1) Compared to my PC config and my graphics card power supply how do you (knowing that it takes at least a 400W)?

2) What are the best brands of smps?

3) In addition to food, can there be another piece of my PC that is not powerful enough to use my CG (genus motherboard, processor or other?)

My PC config:

Processor: Intel Pentium D 940 / 3.2 GHz
Motherboard: Intel 945P Express (Speed Data Bus: 800 MHz)
Ram: 2GB (DDR2 SDRAM)
Hard drive: 300 GB Serial-ATA-300 - 7200 rpm
Graphics PCI Express x16 - plug-in card

[leight]

Buy Antec Earthwatts - 380W that will give an excellent performance and enough for your config.

[goatape]

Thank you for your prompt response.

Do you think if I buy CPU: Intel Core 2 Duo E5200 (Socket LGA775) it's going to do? Is this cpu will be compatible with the rest of my config?