APU Dedicated Memory Explanation?

qsold

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Jul 22, 2014
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So I have a laptop with an APU and there has been some performance issues (it's not performing as well on benchmarks as expected.) A number of product reviewers have stated that it's related to dedicated memory but I don't think they have their facts right. Either way, I'd like to better understand.

When I pull up properties on the GPU I get the following:

Total Available Graphics Memory: 4326 MB
Dedicated Video Memory: 512 MB
System Video Memory: 0 MB
Shared System Memory: 3814 MB

(Side note: Total ram is 1 stick of 8GB RAM)

Now the reviewers were expecting that there would be 4326 MB of dedicated memory, not the 512 MB shown. And they suspect that's the cause of the performance issue.

My question is this: what difference would it make if, for example, I were to increase dedicated memory from 512 MB to 1024 MB? (or whatever... note, I haven't found a setting in BIOS that allows me to do this so I can't just test it as far as I can tell.)

Is there something about how it allocates RAM that would give it a performance boost with more dedicated memory? Because it's the same physical RAM either way.

For example, when I run firestrike and log RAM (GPU-Z) it shows dedicated RAM going to about 500 MB and shared RAM going to about 1000 MB or so (which combined is consistent with what my dedicated card uses).
 

Martin1982

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Sep 30, 2014
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An apu use you ram vram located on your mb. Yes on a pc you can dedicate 1g 2g of ram for graphics.
If you have one stick of ram 8 GB you should be able to use it. Note: 32 bit version of Windows only make you utilize 4 gb
 

qsold

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Jul 22, 2014
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Right. But maybe my question wasn't clear. Let's simplify it a bit.

I have one stick of 8GB RAM.
That RAM is divided up into 3 allocations:

System: ~4GB RAM
Shared (System + Graphics): ~3.5GB RAM
Dedicated: 0.5GB RAM

Given that it's using the same physical RAM, what difference would it make (if any) if I were to change the allocation to, say:

System: ~4GB RAM
Shared (System + Graphics): ~3.0GB RAM
Dedicated: 1.0GB RAM

Again, as far as I can tell, I cannot test this due to the fact that I don't see any settings in BIOS to make the change.

Would there be a difference and why? After all, it's not like I'm going from DDR3 to DDR5 in the case of most desktop gaming setups. And I'm not increasing total available video memory (which remains at 4GB in my simplification).