Upgrading GPU from GT 620

[Xyrophlex]

Hi there,
I'm looking to buy a graphics card to upgrade from my GT 620 so I can play games, mainly CS:GO, at a higher framerate and quality. However I'm concerned about what should be the next step for what I want to do.
This is the PC I have, originally from Dell:
i3-2120
8GB RAM
300W PSU (no extra power cables for graphics cards)
GT 620
I was thinking of getting either a HD 7750 or a GTX 550 ti, both from CEX. My main problem is whether a) my PSU can handle either of these graphics cards and b) whether the GPU requires a 4 pin cable from the PSU to be attached, in which case I cannot use that card.
Thanks for any help received I hope nothing was left out!

 

[clutchc]

With a stock 300W Dell PSU, the fastest card you can find is the GTX 750 Ti. It is faster than the others you list.
Besides, the HD 7750 and GTX 550 Ti are old and require a bigger PSU. They also require a 6 pin PCIe aux. connector.
Get the GTX 750 Ti. It was made for PCs like yours.

 

[Xyrophlex]

@clutchc
My budget is only over £50, maximum 60, so I'm afraid that's a bit outside my price range. Is there anything else you could recommend?

 

[clutchc]

@clutchc
My budget is only over £50, maximum 60, so I'm afraid that's a bit outside my price range. Is there anything else you could recommend?

If you are buying new, the GT 730 is about the fastest card in that price range. Be sure to get the 64 bit, DDR5 vesrion if you do. http://www.amazon.co.uk/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=GT+730&rh=i%3Aaps%2Ck%3AGT+730

It is the preferred entry level card for gaming: http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-2.html

GT 730 vs GT 620: http://gpu.userbenchmark.com/Compare/Nvidia-GeForce-GT-730-vs-Nvidia-GeForce-GT-620/m12582vsm8899