Why GDDR5 over GDDR3?

[masonchaos]

Throughout the last week, week and a half, I have decided on a video card setup. I have narrowed down the selections to the GTX 260 or the Radeon 4770. Now I know the GTX is more powerful but I might have a size issue with my case.

..back to the subject. I have recently learned that the GDDR3 has a larger memory but the GDDR5 has a faster memory.. correct me if I'm wrong. But with the GDDR5's having half as much memory as the GDDR3 what kind of games would I most likely see a difference in running a GDDR5?

I prefer MMO's so loading large areas and large amounts of people would be needed to be loaded quickly and would have to be maintained.

but then I might decided to run something like Call of Duty where I only need to load 1 level at a time and a set amount of people.

So, what would be better for which? GDDR3-GDDR5, MMORPG-FPS?

 

[jsc]

I have recently learned that the GDDR3 has a larger memory but the GDDR5 has a faster memory.. correct me if I'm wrong. But with the GDDR5's having half as much memory as the GDDR3 what kind of games would I most likely see a difference in running a GDDR5?

Not exactly. GDDR5 has a higher bandwidth than GDDR3. That means that for a given clock speed, it can transfer more data. ATI decided to use GDDR5 because, for the same bandwidth, it simplifed GPU chip and PCB design. If you look at the benchmarks for a GTX260 and a 4870, it's a toss up depending on what game is being used.

I do not do MMORPH's, but I think FPS's put a greater demand on the GPU.

What kind of case do you have? I have an Antec 900 case and the GTX260 fits. I just opened up my case and measured. If you have 12 inches of clearance from the back of the case, a GTX260 should fit.

 

[djcoolmasterx]

The GTX260 is 10.5 inches long.

 

[gamerk316]

Essentially, NVIDIA uses slower RAM, but with a larger data bus (512 bit). As such, NVIDIA cards can load more data per GPU cycle, and assuming the card can keep up with the incoming data, will be faster due to loading up to twice the data per cycle.

ATI uses a smaller data bus (256 bit), but faster memory. While the card can load less data per cycle, the faster RAM will greatly speed up the process of applications that needs to load data from the GPU RAM.

It comes down to how games are designed. Games that make use of large portions of GPU RAM will likely run better on ATI, due to the faster RAM speeds. On the other, games that send mass amounts of data to the GPU, but does not need to access as much of the VRAM would likely run faster on a NVIDIA.

In real-world applications, its a push. The GPU will never not load data from the rest of the system (favoring a larger data bus), and will never not have to load data from its VRAM (favoring the faster RAM). While some games may lean one way or the other, the diffrence is often minimal.

*I'm assuing the total power between GPU's is around equal. Comparing a 4890 to a 9800GT wouldn't be fair, now would it?

 

[jsc]

Comparing a 4890 to a 9800GT wouldn't be fair, now would it?

No, but comparing a 4870 to a GTX260 is.