Can someone help me?
I'm thiking of buying a graphic card and i'm considering
the Sapphire HD3870.
I've been using the integrated On Board Graphic of my motherboard
and i'm getting "board" of it.
Now i'm thinking of upgrading.
so my question is will my motherboard Biostar P4M900-M4
support the card?

I have an Intel? Pentium 4 3.2GHz Northwood cpu,
2x (Kingston DDR II 800 1GB),
and Biostar P4M900-M4 motherboard.

yeah it will run that card no problem. Also the card is really nice, I have it in my tri-crossfire, and it's the only one that is air cooled and it only runs like 17c hotter than water cooling.

The board supports it. What kind of power supply do you have?

Yeah it will work,but i think your Board,that P4 and ram might bottleneck that card.

Someone correct me if i am wrong,but yes your card will work

The P4 will bottleneck it but his RAM is perfectly fine. What makes you think it'd be a problem?

My bad,Well you did correct me.Wasn't paying full attention.

It happens.

I have a 380 watt power supply.
What if I overclock my cpu,
would that avoid the bottleneck?

Not really, and that is assuming you can, that doesnt really look like a top of the line motherboard so overclocking may be limited. Also the 380W PSU, and stock cooling might be limiting factors.