That is a fairly low end card I would say adding any newer dedicated video card to an ageing system will benefit it in some way, your lowest fps might be a bit or a lot lower then say someone using an i7, but you will still see a huge performance increase depending on what you are doing. I would honestly say any dual core cpu will not bottleneck a low end gpu. If you are able to you might want to consider buying more ram when you purchase your card, to me that looks like your main bottleneck.