i want to upgrade my graphics card but my mother is intel 945gcpe .i dont know which graphics cards that motherboard will support. So I want to know which graphics card it will support.
The Intel 945gcpe only takes PCI cards. That limits you because 15 years ago AGP replaced PCI for graphics and then PCI-E replaced AGP. PCI-E is not compatible with the PCI.
Only a handful of cards have been released for PCI in the past decade. The ATI Radeon 9000 or 9250 are about as shiny as you'll get for PCI but by modern standards, it's hard to consider either a good option. They're both between £25 and £30 new in the UK. To put some context to this, you can buy a Nvidia GT 430 (low end but modern) for £40.
When you're looking at these prices, you should be weighing up the price of just buying a newer, second-hand, low-end computer. I don't think throwing money at the Intel 945gcpe is money well spent.
In general, every card that has the proper slot - in common language - if the card fits it should work (assuming You have upgraded bios etc). Incompatibility issues are more common with processors and RAM memory. On the intel website there's no single word about problems with supporting graphic cards.
However I recommend to search forums and so on, after You have chosen Your card. Before You buy try to google stuff like:
and see if something shows up. Other thing is that You should buy a card that is well supported by Ubuntu, or I'd rather should say - the vendor provides good linux drivers.
this is a link to your motherboards specifications:
This specifies that the slots are PCI.
Given that these are the recommendations I would make:
Ensure you have a power supply that is capable of running these devices.