Why is a GPU's memory interface width important?

[ZeRedz]

Could someone tell me why the memory interface width GPU is important? Also, I noticed that even though the 960 has a low bitrate in comparison to a 760, it still outperforms it. Why do some people obsess over the interface width? I'd really like to know.

[Stormseeker9]

Quote

There are several memory interfaces throughout a computer system. As it pertains to the GPU, a Memory Interface is the physical bit-width of the memory bus. Every clock cycle (billions per second), data is transferred along a memory bus to and from the on-card memory. The width of this interface, normally defined as "384-bit" or similar, is the physical count of bits that can fit down the bus per clock cycle. A device with a 384-bit memory interface would be able to transfer 384 bits of data per clock cycle (there are 8 bits in a Byte). The memory interface is also a critical component of the memory bandwidth calculation in determining maximum memory throughput on a GPU.

Let's establish an imaginary GPU with a 1000MHz memory clock. At 1000MHz, or 1,000,000,000 Hz, the GPU will execute 1 billion clock cycles per second, each capable of processing instructions. A 384-bit memory interface on our imaginary 1000MHz memory clock GPU would be able to transfer a maximum of 384 bits of data on the memory bus one billion times per second.

 

Copied this from gamers nexus. Hope it helps explain why bus width is important (the greater, the more data can be transferred per second)

[GoldenLag]

5 minutes ago, ZeRedz said:

Why do some people obsess over the interface width?

because some workloads are memmory intensive. 

 

also people dont actually obsess much over it. 

[ZeRedz]

Just now, GoldenLag said:

because some workloads are memmory intensive. 

 

also people dont actually obsess much over it. 

Could you give me an example of such a workload? Also, how important is the memory interface width for gaming? From what I've seen, it's not THAT important.

[GoldenLag]

Just now, ZeRedz said:

Also, how important is the memory interface width for gaming?

depends way too much on the GPU. 

Just now, ZeRedz said:

Could you give me an example of such a workload?

cant from the top of my head. 

[Jurrunio]

10 minutes ago, ZeRedz said:

it still outperforms it.

because the architectures are different, comparing cards of different architectures is not a good idea here

 

10 minutes ago, ZeRedz said:

Why do some people obsess over the interface width?

I've seen more people obsessed with memory capacity than memory bus width. Bus width dont mean anything until you count in frequency to get bandwidth

 

2 minutes ago, ZeRedz said:

Could you give me an example of such a workload?

crypto mining

 

2 minutes ago, ZeRedz said:

Also, how important is the memory interface width for gaming?

So far no card runs out of memory bandwidth for gaming, so not a point of consideration. 

[ZeRedz]

Just now, GoldenLag said:

depends way too much on the GPU. 

cant from the top of my head. 

Is rendering model an example of such a workload? Also, is the memory interface width more important for workstation GPUs?

[GoldenLag]

Just now, ZeRedz said:

Also, is the memory interface width more important for workstation GPUs?

not really. again, it is way to dependant on the GPU and what workload. 

1 minute ago, ZeRedz said:

Is rendering model an example of such a workload?

i wouldnt know. 

1 minute ago, Jurrunio said:

So far no card runs out of memory bandwidth for gaming, so not a point of consideration. 

some GPUs do........

[ZeRedz]

Could someone give a more detailed explanation on what I asked?

[Jurrunio]

Just now, GoldenLag said:

some GPUs do........

for example? I know Vega iGPUs are, an awful lot at that, but they are not in the form of cards.

 

1 minute ago, ZeRedz said:

Could someone give a more detailed explanation on what I asked?

Because the GPU cores dont pull more data in typcial workloads for them.

[GoldenLag]

1 minute ago, ZeRedz said:

Could someone give a more detailed explanation on what I asked?

you asked:

15 minutes ago, ZeRedz said:

Why do some people obsess over the interface width?

answer:

9 minutes ago, GoldenLag said:

because some workloads are memmory intensive. 

 

also people dont actually obsess much over it. 

 

 

you are welcome. 

[GoldenLag]

Just now, Jurrunio said:

for example? I know Vega iGPUs are, an awful lot at that, but they are not in the form of cards.

gt 1030 ddr4 variant, gtx 1650 i believe also and i think the R9 Fury cards may have had a little to little bandwhidt. i could be wrong on the last one. 

[ZeRedz]

I know I don't know much about this kind of stuff in comparison to you guys, but what happens when the memory interface width of a GPU is too little for a game or "workload"? Does this lead to terrible performance?

[GoldenLag]

1 minute ago, ZeRedz said:

ut what happens when the memory interface width of a GPU is too little for a game or "workload"? Does this lead to terrible performance?

its more in relation to how much memmory bandwidth a card has. 

 

 

a memmory limitation in a GPU would lead to lower performance than it would otherwise have. 

[Jurrunio]

7 minutes ago, GoldenLag said:

gt 1030 ddr4 variant,

god dammit, can add other modern DDR graphics cards in as well like the GT730 DDR3 and 940MX DDR3. I disagree with the others, but screw you Nvidia for this crap

 

7 minutes ago, ZeRedz said:

but what happens when the memory interface width of a GPU is too little for a game or "workload"? Does this lead to terrible performance?

Yes. In a 3D workload frame rates will tank hard as if you've run out of video memory, only worse because when you run out of memory space the GPU takes your system memory (so memory used by the CPU) as part of its video buffer so there's a bottom limit for how terrible it will get (until you run out of that as well)

[xAcid9]

2 hours ago, ZeRedz said:

Could someone tell me why the memory interface width GPU is important? Also, I noticed that even though the 960 has a low bitrate in comparison to a 760, it still outperforms it. Why do some people obsess over the interface width? I'd really like to know.

Because more bandwidth = more performance? 

 

960 is on totally different microarchitecture compare to 760 so they're not really comparable in term of bus width, core count, core clock, etc.