I didn't think there was such a thing as the 620i. I found the specs for the 610i (which has a Geforce 7050 so probably what you're looking for), and here they are:
Supports Pentium 4, Pentium Extreme Edition, Pentium D, Celeron D, Core 2 Duo/Quad CPUs on LGA775 socket, minimum lithography of 45nm
Max FSB speed of 1333 MHz
DDR2-667/PC2-5300 single channel memory
18 lanes of PCI Express 1.1 w/out SLI support
5 PCI ports max
Up to 8 USB 2.0 ports
2 PATA/133 ports
4 SATAII ports (3 Gb/s)
100 Mb/s Ethernet
Hi-def audio and Geforce 7050 graphics built-in
The important part of all that is the RAM specification; you can continue to use PC2-5300 RAM, but having multiple sticks won't boost bandwidth, although it may help performance...