MOBO: Your Motherboard has 1x PCIE 2.0 slot. So you are good for upgrading.
PSU: A quality PSU of about 550W or greater will power a single GTX 670 or HD 7950.
Is your new PSU included in the budget of $500?
Usually the difference between cards are small. Some will have better cooling or one may be OC'd while the other isn't. Or some may have dual bios capabilities. I remember my old HD 6950's from sapphire had the ability to be unlocked to 6970's. All in all, it really just depends on what you want. The cards are all going to perform generally the same. If it was me, id go for the cheaper one.
Here is a article about the diffirent HD 7950's available. Maybe it will add a little more clarity to what I was explaining.
If I remember correctly, the GTX 670 out performed the 7950 in most cases. But, then again. The 7950 can OC quite a deal to make it perform much like a 7970. See what others have to say, I hope I was able to help a bit.
the performance between those too cards is very similar, and since your a amd fan I would say go with amd, I prefer either or, just like nvidia's driver support more. the above post explained well the performance differences, also make sure you have a good quality PSU with enough power. everyone has their preferred brands but I have literally never heard anything bad about pc power and cooling for there PSU's.
The GTX 670 can actually grab some good OC's from what Ive read online. But as it is with any other component your overclocking. It is always case sensitive. One person with the same component may not get the high OC's others are able to grab. If you are overclocking your GPU, make sure you case & card is up to the task. You will want to make sure you can keep it cool.
I believe you are correct, I would have to look back at the article.
I honestly would go after the GTX 670. It will out preform the 7950 and as GeforcerFX said. The driver support will be a lot better for the GTX 670.
the 670 can overclock a bit but you could push fermi and even the g92 based cards a lot further, at least at the moment, later kepler revision might be better, but this is just based off a few comments from friends, but kepler is already powerful enough a overclock is not really needed, and taking a quick look back at some reviews the 670 out performs the 7950, but the 7950 can overclock to match, but why not just use the stock clocked card that already wins? I would say gtx 670, but they were like 5 fps apart in most games, not a huge amount imo.
You will need 2x PCIE 6pin connectors
GTX 670 with reference design normally requires two 6pin PCI-E
But some product sometime differ, for example Gigabyte GTX 670 OC is required one 6pin and one 8pin connector.. I recommend you check out first online, there are plenty information/reviews you can get from google
Yeah, but most PCIE connectors will have that extra 2 pins to turn the 6 pin into a 8pin. Just shoot us the link of the PSU you plan to buy and the Card you plan to buy. We will tell you if you got everything you need.
Not only it requires the aforementioned connectors, but also is 3.5cm longer than the reference design. It is nice to remember that this particular model, with factory clocks, can sometimes outperform a reference gtx 680.
Check those reviews
The GTX 670 overclocks very well from what I've heard from other people's experiences, in fact the only thing limiting it is the GPU voltage which is locked. The standard GTX 670 costs $400 so you shouldn't have to spend $500 for a non-reference model, should be around $420-430 if you shop around.
And yeah make sure you get a quality PSU, not a no-name 500W unit for free.