Dell gx280 ram upgrades

[ILL3000gt]

Hello, Im in the process of upgrading my dell gx280. So far I threw in a 450 watt psu (575 watts max) and a evga gr force 7800gt. Im thinking of upgading to a 9800gt or gtx card. The computer only has 1gig of ram. What option do I have as for as throwing more ram in. I want to just put in the largest amount possible and get it over with

 

[ko888]

Which form factor of the OptiPlex GX280 do you have? Small form-factor, small desktop, desktop, small mini-tower or mini-tower? The small form-factor has a maximum limit of 2GB and the rest have a maximum limit of 4GB.

What CPU model is installed in this system?

How many memory slots are currently being used? How many are not being used (i.e. are empty)?

What is the memory timings and voltage of the current memory modules installed on your motherboard?

 

[ILL3000gt]

I have the big desktop version. As for memory slots I have no idea what they look like, Im new to this sorry guys lol. Guess i'll download the cpuz program

 

[ko888]

Refer to this page in the manual:

http://support.dell.com/support/edocs/systems/opgx280/en/ug/memory02.htm