Better for what? Each have distinct advantages and disadvantages for different uses and tasks.
Also, can we get links to all the parts or the model if it is a prebuilt so we have more information on the entire system?
In general, I would go for the first system because of the quad core. This is of course for my uses.
Also, the Nvidia 6100 was one of the last stable Nvidia chipsets that ran at a reasonable temperature.
The other system is faster for single-threaded tasks and the faster ram may provide a slight performance boost overall.