ATI Video Card question

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Soyuz79
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Which of the following in the list below is the most important component when purchasing an ATI video card for high demand games? Why?

MHz Core Clock
Stream Processors
MB Size
bit GDDR5
MHz Effective

Thanks.

hnkftalnot
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As you know the performance of graphics cards corresponds to the type number, 6970 is the best and then performance goes down, 6950, 6870, and 6850 and so on. Only thing the customer can really choose from is memory size, (which matters a lot for the resolution you play at and the size of the textures it can handle) and some manufacturers advertise a tiny increase in clockspeed.

Stream processors are important but you'll see that they follow this trend as well, higher number = higher price = more stream processors. - they are important but just come with the part number AMD has chosen for it.

You don't have to worry about the memory bus (bits/s) as that is fit to the requirements of the memory; you can imagine that a large block of memory needs a wider bus to communicate to the other components, but the way cards are created there will not be any bottleneck by this. Even if you increase the memory speed, the bus width will still be adequate. The little increase in memory speed some manufacturers advertise may be a benefit to some, but if you like to try overclocking you can achieve just the same. Advantage with higher stock clocked memory is that you DON'T have to overclock, and that may be a benefit to most people. But it's easily achievable manually.

If you want to play with large textures on large resolutions then go with more memory, if available for that card. By the way "effective MHz" just means the speeds combined.

GPU clock speed matters a LOT :P. Manufacturers like to variate with it but not by much... AMD has decided on a clockspeed for each chip already and it's up to the manufacturers (or the customers/overclockers) to decide how high that can be. Some manufacturers increase the clock speed a bit (but usually not much), but you can usually increase (overclock) this clockspeed yourself just as well and achieve even higher clocks. So this GPU clockspeed really matters, but the way manufacturers variate with it is just a gimmick in my opinion.

Note that you can't compare AMD with Nvidia this way, they work very differently and just comparing specs like this will not give accurate performance indications.

Soyuz79
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Yes but some ATI cards have lower clock speeds but higher stream processors than others (5870) and other models (6870,6970) have higher clock speeds and lower stream processors.

Which is more important?

hnkftalnot
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Stream processors are very important and a key component to performance. But they are also very expensive, so that's why you see that better/expensive cards have more. Or the other way around; cards that have more stream processors perform better.

Some of the cheaper cards with less stream processors have a higher core clock speed, but that can't compensate for the lack of stream processors. In my opinion the higher core clock speed is just there to keep the card performing well enough even though it has less stream processors compared to it's bigger brothers. - but even at that higher clockspeed they will never perform the same. (hence the price- and part-numbering difference)

Short answer is that stream processors are more important.
Higher (core/memory/stream) clockspeeds just give a boost, but can't compare to more hardware parts on each of those.

But for the 6000 series AMD optimized their architecture, so that they could put a little less of the expensive stream processors on a card. Not entirely sure about that but the benchmarks seem to indicate that. By the way, real-world benchmarks are always a better way to compare hardware than just by their hardware numbers.

Soyuz79
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OK so Stream Processors are the most important factor of ATI video cards when judging their performance capability.

That’s why the 5970 series costs allot.

dustyschaffner
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Streaming processors are the thing that makes the most difference but its a better idea to look at the benchmarks. Specs can sometimes lie compared to what the real performance of the card actually is.

Soyuz79
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Are 5870's better than 6870's?

hnkftalnot
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Yes. The new 58xx cards are the 6950 and 6970.

Soyuz79
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But the 6970 have less Stream processors than the 5870 how is it the same?

hnkftalnot
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6970 has 96 stream processors and the 5870 has 80, isn't it? It's also higher clocked.

Soyuz79
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You mean texture units.

Which matters more and why? (Stream Processors or Texture Units)