How exactly does a graphics card work?

[AssaultRifle]

I'm quite new to the whole PC building thing, so I had a question about graphics cards. For instance, how come a Radeon HD 5750 performs better than a Nvidia GT 220? They are both 1GB cards, so shouldn't they perform the same?

Could somebody explain to me how a graphics card works, and what makes a 5750 better than a GT 220? (Just picked those 2 cards because I know they are quite different in performance)

 

[mickey megabyte]

the 1 gb memory has nothing to do with speed - it merely refers to the amount of memory (and hence texture detail for games) on board.

without getting too technical, graphics cards have a dedicated graphics processing unit - a gpu.

different cards have different gpu's, running at different speeds. the graphics memory (vram) also runs at various speeds.

an expensive card will have a fast gpu, and lots of fast vram, and will give a much smoother higher framerate in games, because it can 'crunch numbers' faster.

it's a bit like asking why does a 3 GHz intel processor perform better than a 300 MHz amd...or why does a ferrari go faster than a ford if they both have four seats.

wikipedia page for more detail

 

[Fumz]

... it's a bit like asking why does a 3 GHz intel processor perform better than a 300 MHz amd...or why does a ferrari go faster than a ford if they both have four seats.

:roflmao:

Best analogy this year.

 

[Nikkeli]

What you should be looking on the cards, is shader processors (SPs), what kind of memory it's using (GDDR) 5 is currently in the high end cards, higher is better ofcourse.
Third thing is memory bandwidth, its measured in bits, and higher is better, currently fastest single GPU is Nvidias GTX 480 which has 480 CUDA cores (Shader processors) and 384 bit memory bandwidth and it runs on GDDR5, now GT 220 has only 48 SPs and memory bandwidth is only 128 bit and uses GDDR3, you can see the difference is huge, GT 220 is no gaming card really, it's low budget casual gaming or just generic GPU that can handle fair amount of stuff.

What you need to remember is that ATI cards use different technology and they've got generally more SPs on their cards which doesn't translate to more power, so you can't directly compare by SPs between ATI and Nvidia.

Now we know GT 220 has 48 cuda cores (not relevant when going against ati) 128 bit memory bandwidth and GDDR3 with 1GB of memory. (also core clock and shader clocks affect directly to performance, they can't be compared because different GPU can run at same speed but isn't nearly the same).

When we look at ATI's 5750 first thing we notice is that it has GDDR5 (big plus).
Second thing we notice is it has Direct X 11 support, which is nice when some dx11 games start rolling in that aren't designed for high end PCs.
It also has 128 bit memory bandwidth.

ATI 5750 is definitely the winner here but you'll see that in price tag too, GT 220 costs around 60 euros around here and ati's card is around 140's.

There's some basics so you can compare some cards and pick the one that suits you without getting fooled by the model names which sometimes are confusing.

edit: wow god damn this became long post... hope it aint too long and somebody actually bothers to read it

edit2: something about the amounts of memory:
the memory size in most cards is overkill when comparing it to their performance, most games run just fine with 1GB, but some like GTA IV can require more if you tweak the settings like so, but theres no way you can even run that game with GT 220 or even with 5750 in such high settings so that VRAM (memory) would get filled, basicly, more memory won't give more performance, that's something many "noobs" are confused about and that's one thing that stands out from the cards when you're shopping, but it's not relevant at all to measure how good the GPU is.

 

[AssaultRifle]

What you should be looking on the cards, is shader processors (SPs), what kind of memory it's using (GDDR) 5 is currently in the high end cards, higher is better ofcourse.
Third thing is memory bandwidth, its measured in bits, and higher is better, currently fastest single GPU is Nvidias GTX 480 which has 480 CUDA cores (Shader processors) and 384 bit memory bandwidth and it runs on GDDR5, now GT 220 has only 48 SPs and memory bandwidth is only 128 bit and uses GDDR3, you can see the difference is huge, GT 220 is no gaming card really, it's low budget casual gaming or just generic GPU that can handle fair amount of stuff.

What you need to remember is that ATI cards use different technology and they've got generally more SPs on their cards which doesn't translate to more power, so you can't directly compare by SPs between ATI and Nvidia.

Now we know GT 220 has 48 cuda cores (not relevant when going against ati) 128 bit memory bandwidth and GDDR3 with 1GB of memory. (also core clock and shader clocks affect directly to performance, they can't be compared because different GPU can run at same speed but isn't nearly the same).

When we look at ATI's 5750 first thing we notice is that it has GDDR5 (big plus).
Second thing we notice is it has Direct X 11 support, which is nice when some dx11 games start rolling in that aren't designed for high end PCs.
It also has 128 bit memory bandwidth.

ATI 5750 is definitely the winner here but you'll see that in price tag too, GT 220 costs around 60 euros around here and ati's card is around 140's.

There's some basics so you can compare some cards and pick the one that suits you without getting fooled by the model names which sometimes are confusing.

edit: wow god damn this became long post... hope it aint too long and somebody actually bothers to read it

edit2: something about the amounts of memory:
the memory size in most cards is overkill when comparing it to their performance, most games run just fine with 1GB, but some like GTA IV can require more if you tweak the settings like so, but theres no way you can even run that game with GT 220 or even with 5750 in such high settings so that VRAM (memory) would get filled, basicly, more memory won't give more performance, that's something many "noobs" are confused about and that's one thing that stands out from the cards when you're shopping, but it's not relevant at all to measure how good the GPU is.

I actually read the whole thing, and this is VERY good information. It was just what I was looking for. Thanks