DDR3 vs GDDR5

[shrewdgamer]

When choosing a card? Which should be preferred and why? Will a card of DDR3 memory be slower than the same card with GDDR5 memory? How does it effect the graphics in a game? Which consumes less power?

 

[homerdog]

GDDR5 is much, much better than DDR3. Don't get a DDR3 card if you want to play games.

Also I think this is the wrong forum for that kind of question.

 

[Wynix]

It's a significant performance gap between them when using the same silicon, here is some test results of 7750 DDR3 vs the GDDR5 version:

Buy the GDDR5 version, even 1GB GDDR5 is better than 4GB of DDR3 for the vast majority of tasks.

 

[HMBR]

It's a significant performance gap between them when using the same silicon, here is some test results of 7750 DDR3 vs the GDDR5 version:


Buy the GDDR5 version, even 1GB GDDR5 is better than 4GB of DDR3 for the vast majority of tasks.

this graph is comparing 4500MHz GDDR5 to 1600MHz DDR3, both 128bits,

it can be worse or better for DDR3, some cards go even further down using 1333 ram, or even worse cutting to 64bits, but some cards could also be using 1800, 2000MHz DDR3 which could make the difference smaller

but overall, stay away from DDR3 cards when a GDDR5 version exists, the DDR3 version is normally not cheap enough to justify the performance difference, and only exists as a trap to make money with people that have no clue about what they are buying.

 

[Snyder]

Or you can go the nvidia route: Upgrade the gf 640 to GDDR5, cut the width from 128 to 64.

 

[Pixel]

And it gets even further worse still with cards like the 7850 and higher having 192bit-320bit width and not just 128bit wide memory bus width and memory configuration.

 

[Albuquerque]

And it gets even further worse still with cards like the 7850 and higher having 192bit-320bit width and not just 128bit wide memory bus width and memory configuration.

Wait, what? I don't get what the complaint is here. Does it bother you that 192 and 320 are not evenly divisible by 128? Because I'm not sure that you're following the gist of this conversation, if that's truly your complaint.

 

[UniversalTruth]

Or you can go the nvidia route: Upgrade the gf 640 to GDDR5, cut the width from 128 to 64.

... Here you would get the same end result, since GDDR5 offers twice the bandwidth compared to GDDR3

 

[DSC]

http://www.techpowerup.com/gpudb/2377/geforce-gt-640-rev-2.html

Bandwidth: 40.1 GB/s

http://www.techpowerup.com/gpudb/813/geforce-gt-640.html

Bandwidth: 28.5 GB/s

GK208 GDDR5 is still faster than GK107 DDR3 even with a 64bit memory bus.

 

[Deleted member 13524]

GK208 DDR5 is still faster than GK107 DDR3 even with a 64bit memory bus.

Are you sure? Even though the GK208 is clocked higher, the GK107 has twice the ROPs.

 

[AlNom]

Very likely those 16 ROPs are bandwidth starved.

 

[DSC]

http://hexus.net/tech/reviews/graphics/59081-nvidia-gainward-geforce-gt-640-rev-2-gk208/

Benchmarks pretty much agrees, GK208 GDDR5 with half the TMUs, half the ROPs & 64bit memory bus beats GK107 DDR3 128bit memory bus in performance, doesn't lose in a single benchmark.

 

[Pixel]

Wait, what? I don't get what the complaint is here. Does it bother you that 192 and 320 are not evenly divisible by 128? Because I'm not sure that you're following the gist of this conversation, if that's truly your complaint.

Just pointing out that the discrepancy between gddr5 based cards and ddr3 based ones gets larger and larger with higher end cards.

 

[UniversalTruth]

this graph is comparing 4500MHz GDDR5 to 1600MHz DDR3, both 128bits,

it can be worse or better for DDR3, some cards go even further down using 1333 ram, or even worse cutting to 64bits, but some cards could also be using 1800, 2000MHz DDR3 which could make the difference smaller

Yup, pretty much depends also on the memory frequency regardless of its type, be it GDDR5 or 3, and bus width

but overall, stay away from DDR3 cards when a GDDR5 version exists, the DDR3 version is normally not cheap enough to justify the performance difference, and only exists as a trap to make money with people that have no clue about what they are buying

http://www.techpowerup.com/gpudb/813/geforce-gt-640.html

http://www.techpowerup.com/gpudb/2377/geforce-gt-640-rev-2.html

Here, in this example it is the opposite- perhaps because of the bigger die and its cost, and double the memory size, you have the DDR3 card actually being more expensive

http://hexus.net/tech/reviews/graphics/59081-nvidia-gainward-geforce-gt-640-rev-2-gk208/

Benchmarks pretty much agrees, GK208 GDDR5 with half the TMUs, half the ROPs & 64bit memory bus beats GK107 DDR3 128bit memory bus in performance, doesn't lose in a single benchmark.

But keep in the mind that the GK208 was released one full year later and perhaps has a lot of small optimisations included in it, thus making the impact of GDDR5 not the most important to emphasize

Just pointing out that the discrepancy between gddr5 based cards and ddr3 based ones gets larger and larger with higher end cards.

Radeon 7850 doesn't have GDDR3 versions, so it can be said that higher end cards don't have different versions

 

[Pixel]

Radeon 7850 doesn't have GDDR3 versions, so it can be said that higher end cards don't have different versions

Of course not. They are forced to go with gddr5 to achieve a certain memory bandwidth. I'm saying comparing the bandwidth of high end gddr5 based cards with mid* to low range ddr3 based cards.

*Assuming I can call a 7750 ddr3 a mid tier card.

 

[Tahir2]

Of course not. They are forced to go with gddr5 to achieve a certain memory bandwidth. I'm saying comparing the bandwidth of high end gddr5 based cards with mid* to low range ddr3 based cards.

*Assuming I can call a 7750 ddr3 a mid tier card.

So lets talk about a hypothetical unreality (TM) rather than real life?

** Scratches head... ** Still don't get your point buddy.