Graphic Card is what most people love to upgrade or sometimes they are forced to do so, mainly when they find their integrated GPU too slow to be called one.

If you are going to buy a graphic card then the following things which you gonna read will be very useful for you to decide which graphic card to buy, how to find which Graphic Card is good one and which is not ?

Don’t worry, I won’t make you recall 10th grade physics and mathematics, I would try to use simple language to make you understand basics of buying good GPU.

Memory

1 GB, 2 GB or 4 GB graphic card ? In the perspective of a beginner or intermediate computer user – higher the memory, faster the speed. If you too think the same way, like many of us do then you are wrong! Higher memory theory might suite to RAMs but not graphic card. Scrolling through the list of graphic card, a 2 GB or even 4 GB graphic card would attract our attention more than 1 GB one. In reality a 1 GB graphic card is more than enough for gaming, unless and until you decide to interconnect a dozen of monitors and show uncle Sam how hardcore gamer you are.

So if you just want to play game on a normal computer monitor and have nothing to do with uncle Sam then 1 GB or 1.5 GB max graphic card is suffice for you.

GPU Speed

A graphic card actually transfers stress from CPU and take it on itself. Yes, you guessed it correct, Graphic Cards too have processors in them and like CPU they too have speed.

Normally speed of GPU(Graphic Processing Unit) is calculated in Hertz(Hz). In the market you can find Graphic Cards with clock speed(or GPU speed) ranging from 500 MHz to above 800 MHz. If you are not so fond of gaming then a graphic card with clock speed 600 MHz to 750 MHz would fine for you. Hardcore gamers, look above 750 MHz

Remember : Now a days some of the graphic cards have clock speed in GHz i.e. above 1000 MHz. So by just looking at clock speed, don’t buy them blindly because many times other factors of graphic cards such as bus speed(you gonna read it next) are in poor state.

Bus Speed / Bus Width

Suppose you grabbed a fast clock GPU with higher memory but what if your graphic card actually doesn’t posses skills to transmit and handle this data ? Here comes one of the main performance determining factor, Bus Speed (or Bus width). It tells us how fast the graphic card is in transmitting(and receiving, as few people say) data across memory. Faster the bus width, faster the data processing, faster the game and overall a faster graphic card.

A graphic card can have 64-bit, 128-bit or even 256-bit and above bus width.

Memory type

Just like RAMs, Graphic Memory modules too have generations. A 1GB DDR5 graphic card is much better than a 1GB DDR3 card. Many times a same graphic card model would be available in both DDR3 and modern DDR5 version and in such situation it is recommended to go with DDR5. Also note that a DDR5 1 GB Graphic card with 128-bit bus width will perform same as 1GB DDR3 graphic card with bus speed of 256-bit.

So these were some of the important factors which determine how good a graphic card will perform. These were some of the important factors which can determine performance of graphic card but there are others too like Memory Bandwidth, a simple mathematical calculation of overall speed of graphic card and Stream Processors.



Source: Internet. Total Credits to Original Author.

I would say, that energy consumption, noise levels and temperature are important parameters too when buying GPU.

Originally Posted by RandomNickName87

I would say, that energy consumption, noise levels and temperature are important parameters too when buying GPU.

True.
I am not a gamer and i don't care about a very good GPU. The most important for me is the low noise that's why all my PC parts are very low or even zero noise.
I am on the PC 15 hours per day and every single DB of sound is VERY annoying !

gr8 lesson for beginners
REP added

Great Guide for first time buyers.