AMD shared VRAM size (hardware reserved memory)

[Rufus5]

Hi all, 

There is a bug in shared VRAM size calculation for AMD-based laptops. I've read through many similar topics here and it seems Ryzen and Athlon machines with integrated GPU are affected. 

Here are results for my Athlon 300U-based machine:
* 1x4Gb(factory RAM setup) -- 512Mb reserved for GPU
* 2x4Gb -- 2Gb reserved 
 
There is no way to change VRAM amount in BIOS, which leaves my laptop with 25% RAM inaccessible for no reason. 
I see no rational explanations at this forum why it's not possible to control the VRAM amount and bunch of similar topics are still open. 

Most of replies here are like "change you pagefile/swap size", "untick Maximum Memory at msconfig", i.e. useless. 
Same is true for the statements like "laptop BIOS is tuned for maximum performance and locked to protect the hardware" -- what kind of optimization tuning is this? It sounds like deducing the CPU freq from SSD capacity or screen brightness from mouse cursor speed.

It will be great if someone at this forum can pass this issue further to a tech team. I'm sure there is a way to resolve it, hardcoded VRAM sizes for the different RAM configurations is the worst idea ever, while something like switch 512MB/AUTO will work in most of cases. 

Crossing my fingers that you can cope with this problem! 

Best, 
R

[banhien]

@Rufus5 

Sorry, your math is not right. The specs of your machine is

   https://support.hp.com/in-en/document/c06488498

which has   AMD Athlon™ 300U with Radeon™ Vega 3 Graphics (2.4 GHz base clock, up to 3.3 GHz max boost clock, 3 MB cache, 2 cores) and AMD Radeon™ Vega 3 Graphics is an Integrated Graphics.

Integrated graphics SHARES system RAM and your machine has ONLY 4 GB DDR4-2400 SDRAM (1 x 4 GB) that means system does not have much spare/available system RAM to be able to allocate more for VRAM. 512MB is a reasonable amount of RAM system can share. Do you expect system gives VRAM 2GB and it will ONLY RUN WITH 2GB ? I don't think so.

You can't modify BIOS. One way to increase shared VRAM is to add max limit system RAM (if allowed). For your machine, you can add 4GB more to slot 2 or upgrade to 2 x 8GB to 16GB.

Regards.

[Rufus5]

@Banhien 

Yup, you're right, I described the problem using wrong word, it should be "shared" instead of "dedicated" in my initial message, I'll update the post. But anyways, the issue is still there. 

You see, I don't need more VRAM, I need less VRAM! In other words, I want to use my RAM, and I don't want 25% of RAM to be reserved as VRAM. This is a way too high default value which is hardcoded somewhere in BIOS sources.

> 512MB is a reasonable amount of RAM system can share
That's true, but 2Gb for the system with integrated GPU is not. 

Best, 
R

[banhien]

@Rufus5 

System will work this out AUTOMATICALLY to decrease/increase shared RAM when required up to the max allowed.

Regards

[Rufus5]

@Banhien 

Well, this is not true, I have verified it on both Linux and Win10. So essentially when overall memory utilization is close to RAM - VRAM Gb(5.9Gb in my case), system starts to swap or kill processes with highest memory footprint. 

[Rufus5]

It's worth noting that I'm using the latest available BIOS version: F.42 Rev.A. 

[Rufus5]

And here's a list of similar topics for the last couple of months: 
https://h30434.www3.hp.com/t5/Notebook-Video-Display-and-Touch/HP-17-ca1211ng-No-BIOS-setting-for-sh...
https://h30434.www3.hp.com/t5/Notebook-Operating-System-and-Recovery/Less-usable-RAM-than-installed-...
https://h30434.www3.hp.com/t5/Gaming-Notebooks/Reserved-ram/m-p/7267773
https://h30434.www3.hp.com/t5/Notebook-Hardware-and-Upgrade-Questions/Hardware-reserved-memory-usabl...
https://h30434.www3.hp.com/t5/Notebook-Hardware-and-Upgrade-Questions/Upgraded-RAM-unusable-Shown-as...
https://h30434.www3.hp.com/t5/Notebook-Hardware-and-Upgrade-Questions/Windows-10-Showing-Large-amoun...
https://h30434.www3.hp.com/t5/Notebook-Boot-and-Lockup/Hardware-Memory-reserve/m-p/7212138
https://h30434.www3.hp.com/t5/Notebook-Software-and-How-To-Questions/Change-reserved-UMA-framebuffer...

[Rufus5]

Hi @Banhien,

So you mentioned that 

"System will work this out AUTOMATICALLY to decrease/increase shared RAM when required up to the max allowed."
Do you mean that system is able to adaptively adjust the reserved RAM size at runtime? Is my understanding correct? 

[Rufus5]

Hi HP support, 
Could you stop ignoring this issue, it is not resolved so far and there was no even a single reply with any rational explanation from HP! System is eating 1/4 of my RAM for no reason! Things like "system will work this out AUTOMATICALLY"  are nonsense. 

[fundamental]

I totally agree with you. It is a shame for HP not solving this ram issue.