Any recent PCI Express card will do really. You just might want to check that it's superior to the Intel GMA X4500 built-in graphics.
There are two different versions of the X4500 used with the G41 chipset. One has device ID 2E32 and the other is 2E33. You can check the device ID in Device Manager in Windows if you care.
Here are some specs on the X4500:
800 MHz core render clock
shader model 4.0
directx 10
open gl 2.1
memory bandwidth 12.8 GB/s (DDR2) and 17 GB/s (DDR3) this depends on if yours is DDR2 or DDR3
1700 MB DVMT memory
Source:
http://en.wikipedia.org/wiki/Comparison_of_Intel_graphics_processing_units#Fourth_generationThe Geforce GT620, codenamed GF108 (retail version). There's a higher model GT620, codenamed GF119 (OEM version). But the one you mention is GF108 because it's an aftermarket product and it's the only one available with 2 GB memory configuration. The GF119 is low on memory but high on other specs. So here are some the specs for the GF108.
2048 MB memory
700 MHz core clock
memory bandwidth 8 - 14.4 GB/s
DRAM type DDR3
directx 11
opengl 4.4
Source:
http://en.wikipedia.org/wiki/Comparison_of_Nvidia_graphics_processing_units#GeForce_600_SeriesYou should be able to play newer games with the GT620 as it supports the latest API versions. Even if you don't play games with it you still win, because you don't share the memory with the rest of the system (1700 MB
DVMT). But I would suggest a little higher model, perhaps GT630 (GK208). If the price is not right then I suggest you go for Radeon. They have cards with comparable performance for a lower price.
