Graphic cards, Its confusing me

[Abro125]

Hi guys there are many types of gcs at thr market some got more memory and some got more bit for example if im going for 128 bit i can buy a 4 gb memory g.card and if im going for 256 i can buy Only 1 gb memory gcard... So what makes me confused
1. Ddr5 type
2. Ddr 3 type
3.128 bit
4. 256 bit
So the question is that what is the actual performance difference between 1&2 and 3&4

 

[DSzymborski]

These things are only relevant for similar cards. For example, the GDDR5 version of the GT 730 is better than the GDDR3 version. These performance differences are dwarfed by more important information.

If you're not familiar with GPUs, Tom's GPU Hierarchy is a useful place to start shopping.

http://www.tomshardware.com/reviews/gpu-hierarchy,4388.html

 

[dontlistentome]

Generally, you want DDR5 memory in your videocard. DDR3 is just too slow for modern games.

Memory amount is a secondary concern, not the most important thing. A slow card with lots of memory is still a slow card. A 1gb fast card can outperform a 4gb slow card, because processing power is what determines speed, not memory amount.

The bit number determines memory bandwidth. This is important in determining performance as memory demands go up. For example, a 64 bit card has less memory bandwidth than a 128 bit card, so all other things being equal the 64 bit card will lose framerate much faster as resolution goes up. Increasing resolution will increase memory operations, which requires more bandwidth. However, like with memory amount, memory bandwidth does not by itself guarantee faster performance. A 128 bit card can outperform a 256 bit card, since the processing speed can make the lower bandwidth irrelevant.

There is no specific performance difference between DDR5 and DDR3, all you can say is DDR5 is faster. There is no specific performance difference between 128 and 256 bit, all you can say is 256 bit allows for more bandwidth.