You will have to upgrade that whole system once you get some money together, but for now you can upgrade the gpu first.
Id suggest getting a geforce GTX 750ti 2GB GDDR5 128bit card. it only uses 60w of power. so you dont need to upgrade your power supply
When buying a new gpu, there are a lot of factors coming into play.
DO NOT JUST GO IN AND BUY THE FIRST 2GB CARD YOU SEE!! more memory doesnt necessarily mean best performance
Have a look at the model number
Im going to use the "GTX 750 ti" as an example
The first digit is the series
7 Series is the latest nvidia have to offer. they use less power than previous generations while performing better
The last two digits is the performance class of the Gpu
10 is entry level
50 is mid range
80 is high end
and then finally you get the TI at the end, its usually for the cards that fall in between the performance brackets.
for example GTX 760 > GTX 750ti > GTX 750
also look at the memory on the gpu. The memory type and memory bitrate is an important factor.
DDR5 is twice as fast as DDR3
DDR5 128bit is just as fast as DDR3 256bit. - the ram can fill up at around the same speed
DDR5 256 bit is twice as fast as DDR5 128bit - the ram fills up at a higher bit rate meaning more data can pass through
I could go on for hours but i think thats enough for now, lol
Hope i could help just a lil bit.
Regards
The Cow
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