Video Card RAM question

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Iceman
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Video Card RAM question

Post by Iceman »

I am confused ... I see specs for 128 bits, 256 bits, DDR, and DDR3. Can someone enlighten me on the differences here and which would perform better? I assume DDR3 would be the fastest ..
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Post by fliptw »

you want to pick one with the widest bus size, so avoid cards that say 128-bit bus.
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Post by Iceman »

But what is DDR3? Does it come with both 128 bit and 256 bit busses? The specs I have seen for the DDR3 boards don't include the bus width.
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Post by fliptw »

if they don't specify then don't worry. you'd generally find 128-bit buses on the cheapo versions of the cards anyways.
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Post by Mr. Perfect »

GDDR3 memory is very expsensive, and is usually reserved for the highend cards, which would have 256bit anyhow. As far as I know, GDDR3 is not faster then GDDR1 at the same clock speed. It's designed to run cooler, use lower voltages, and handel higher clock speeds. Meaning they only use it when they have to really crank the memory speeds up, and DDR 1 can't handel it.
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Post by Krom »

You hardly ever see a video card with DDR1 in it anymore, most have DDR2, and the newer ones have DDR3. The only real difference between them is the clock speed, DDR3 can run faster then DDR2.

As for 128 vs 256 bit, at the same speed 256 bit memory has double the bandwidth of 128 bit memory, and the more memory bandwidth video cards have the better.
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Post by Iceman »

Excellent, that is what I needed to know. Thanks guys :)
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Post by Mr. Perfect »

GDDR2? Are you sure? The 256MB 9800 Pro used GDDR2 and it was hot as balls. I thought they reverted to GDDR1 for low/mid range cards in most cases.
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Post by Frosty5F11 »

midrange usually have 128bit and higher end has 256bit.
256 effectively doubles the effective bandwidth which means if a 128bit ddr was doing 700mhz effective, it would be still 700mhz in 256 but effectively 1400. Mostly comes in handy for anti-aliasing and aniscropic filtering.
and don't be fooled by 256mb for slower cards, just a sales gimmic, by the time it uses that extra memory it don't have the power for good framerate.
if going radeon 9800 or geforce 5900 or higher, go for 256mb, anything lower save your money.
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