Learning to evaluate GPUs

[Secant]

Hi All,

I am looking to buy a new laptop (have been now for a few months). I will likely buy the from xoticpc and need a laptop for because I travel frequently for work, but love my gaming! The part that still has me confused a bit is evaluating GPUs. Some of the new lower 6xxM NVidia cards have a higher "MB" than some of the higher end old cards. Two laptops that I am considering are similar prices, but one has the

nVidia GT 630M 2048MB PCI-Express DDR3 DX11 with Optimus™ Technology

and the other has the

nVidia GeForce GTX 570M 1,536MB PCI-Express GDDR5 DX11

At first glance, the 630M seemed to be a better card, as it has the 2048MB like the 580M has. However, I looked at some benchmarks, and it seems like the 570M 1536MB card is performing quite a bit better. (source: notebookcheck) This tells me that I probably don't really understand much about GPUs =(

Thanks for any help!

[Mazzop]

anything more that 1gig of memory in gpu is probably a waste and 570M have GDDR5
dig if it have 256bit or 128

[Nellah]

The first number in NVIDIA card names is the generation, the second two are the performance levels. A GTX550 is far inferior to a GTX480, for example. Look at the spec sheets for how many execution units a card has and you'll find more clues to their performance levels. (This did get shuffled a bit with Kepler as they're running more EUs at lower clock speeds.)

Naturally, performance levels generally get higher with each generation. A GTX680 is better than a GTX580 is better than a GTX480, for example. Of course, there are exceptions, so it is good to dig, but to cut to the chase and answer your question, the 570M positively murders the 630M, with 2.5-3 times as many shaders (depending on what rebranded card the 630M ends up being... the mobile market is a fiasco.)

[LordPeter]

the "MB" does not matter. anything higher than 1gb on a laptop is useless.