Upgrade GPU now or later? 7870 or R9 270X

[Cesarb12]

So right now I have a Corsair 450 VX. I had been researching and found that the 7870 is rather affordable for me at about 100-120ish (used). I was set on getting it, but now I'm troubled because as I keep looking into slightly newer cards, they're only ever so slightly more expensive. R9 270X supposedly it's slightly better than a 7870? I found some between 110-130. I know if I get the R9 or the 7870 that I can not overclock it because I'll be pushing my PSU too much. Would it be better to get an R9 270x now and run it with my current PSU, then in like 2 or 3 weeks get a better PSU so I'm not stressing my Corsair? Or should I get a new PSU and then a R9? I do realize I need to get a 4 pin molex to 6 pin PCI-E, as my current PSU only has one 6 pin. If it matters, I currently have a HD 4850 1GB and a i7-920. One 500GB HDD and 8GB PNY 1333MHz RAM.

 

[11sphere92]

getting a new PSU first is better, since it will only make more capacity, since if u buy those GPU first and you cannot use em, it would be a waste right?

 

[Cesarb12]

getting a new PSU first is better, since it will only make more capacity, since if u buy those GPU first and you cannot use em, it would be a waste right?

Seen so many threads that those cards can run with a good 450w PSU. Only reason why I'm asking if I should get the GPU now and then a PSU in a couple of weeks.

 

[Calculagator]

The 270x is a slightly overclocked 7870 with faster memory. You can overclock a 270 to be identical to the 270x.
http://www.anandtech.com/show/7503/the-amd-radeon-r9-270x-270-review-feat-asus-his
The newer cards should be better at using less power. The 270 sometimes only requires a single power connector. You are not going to notice much difference either way. A few bucks more may get you a bit better performance.
You could also pick up a 7950 for about $130 which will outperform the 270x. Your PSU should handle the single card just fine.

 

[Cesarb12]

The 270x is a slightly overclocked 7870 with faster memory. You can overclock a 270 to be identical to the 270x.
http://www.anandtech.com/show/7503/the-amd-radeon-r9-270x-270-review-feat-asus-his
The newer cards should be better at using less power. The 270 sometimes only requires a single power connector. You are not going to notice much difference either way. A few bucks more may get you a bit better performance.
You could also pick up a 7950 for about $130 which will outperform the 270x. Your PSU should handle the single card just fine.

Just checked and it would still be in my budget to get a 7950, thanks. I'll be getting another branded PSU in a couple weeks anyways too.