What to look for in video cards

gaming performance is the end result anyways, so
http://www.techpowerup.com/reviews/Axle/GeForce_GT_240/...

and memory size isnt really a key factor, 512M is enough up to 1680x1050 depending on the game, 1G beyond that point... (if the core has enough muscle to actually run anything at those resolutions)

and (G)DDR3 is way better than DDR2, even for the low end cards. So 512 DDR3 is better than 1G DDR2 variant of the same card

The higher they are on this list the better they are regardless of memory size. http://www.tomshardware.com/reviews/geforce-310-5970,24...

No, never regardless of memory.
A 128MB 4870 isn't going to best a 1GB 4670 at 1920x1200.
The memory won't matter until a certain extent. 512MB will suffice up to 1920x1200 (without AA), (G)DDR5 > (G)DDR4 > (G)DDR3 > (G)DDR2.
This is the order of importance.
Core (ie. 4850 > 9600GT)
Memory Type and/or bus (DDR5>DDR3) (256bit > 128bit)
Memory Size (1GB > 512MB)

Where can I find a 128mb HD4870?
1gb is only better than 512mb on a card at same level of performance.

I'm not saying you can, but that would still disprove your statement of memory size doesn't matter.

It does. It's just that USUALLY core & mem type matter more.

Don't forget that anything below HD4850 or GTS250 is hardly powerful enough to take advantage of 1gb of memory since you hit the core limit before you hit the memory limit.

I thought higher memory cards (1GB) only showed significant differences at higher resolutions as well.

That is true!

Look at any two cards at the same price point.

The best one has a red sticker with ATI on it. The worst one has a green sticker with Nvidia on it.

Armed with that knowledge, you are now better off than most people about to buy a graphics card.

ignore jennyh, always take a look at the numbers and reviews. For a quick reference take a look at the best graphics card for the money article. The last page of the article has a hierarchy chart to show you the relative performance of most cards out on the market now.
http://www.tomshardware.com/reviews/geforce-310-5970,24...

No listen to jennyh.

That most recent best graphics card article only has nvidia cards in it because the ATI's were so hard to find. Had they been in decent supply there wouldn't be a single nvidia card on the list. Sure you can maybe buy something like a gts250 now but in a months time it will be money badly spent.

Anybody who knows anything about graphics cards knows this is true.

Graphics cards are always changing. I feel like there is always something fantastic and new right around the corner, so I guess you are right - in a few months, it always feels like you could get more.

I do agree, ATI is doing well in the GPU market - congrats to them. It's nice to see competition again.

I'd have to say check the charts and benchmarks to help make your decision - don't get caught up in loving one company or another.

Thanks guys, I still didn't buy the computer and i'll probably get a PCI-E ATI HD4870 1GB XFX DDR5 256Bits for the video card, but i might change it for a 512mb depending on how much of those i can find and how cheap(compared to the 512)

What does the (G) mean? Sometimes I see it, sometimes I don't. Does it matter when looking at graphics card specs?