IGPU shows 7Gb of VRAM

[iLikeHackintosh]

At best a IGPU can only use a maximum of 2GB on MacOS so something is way off there

Hi @jaymonkey

Actually 630 can use up to 64GB memory according to Intel Support information for Intel® HD Graphics 630 website.

Why do you think there should be a limit on macOS? I have 64GB memory installed on this comp.

Edit on December 20, 2019

As this post and many other posts in this thread are extracted from another thread, an update for first post is needed to reveal the topic more clearly.

I posted a screenshot of HWMonitorSMC2 app GUI that shows approximately ~7GB of free shared video memory on Intel HD Graphics 630 which were causing a question about validity of value. My initial thought was that there is a bug in HWMonitorSMC2, but that's not true, as readings shown in HWMonitorSMC2 are generated by native Apple drivers.

I have investigated this issue and I can confirm that the statements below are true:

• Intel HD Graphics 630 supports up 64GB of memory
• Apple macOS supports more than 2GB of shared video memory
• Value of shared video memory size (iOKit -> gartSizeBytes) is generated by Apple Metal drivers

I have attached dump of original iMac19.1, which confirms statements listed above.

New technology has opened new horizons, even for Apple. Apple relies on Metal now, which brings new ways to use graphic units and it's time for Hackintosh community to stay tuned too and learn more how Metal affects building and usage of macOS based comps.

 

[jaymonkey]

Why do you think there should be a limit on macOS? I have 64GB memory installed on this comp.

@iLikeHackintosh,

MacOs will only ever use a maximum of 2GB VRAM with a IGPU (actually its 1.5GB by default but this can be overridden to 2GB via the 2048MB VRAM patch), its a limit thats hard coded into the MacOS IGPU driver stack. MacOS only ever uses the IGPU for lite compute work (IQS, AirPlay, SideCar ..etc) on desktop systems such as iMacs where the IGPU is configured as headless. On mobile systems such as MacBook Pro's the system will use the IGPU for MacOS UI to save battery power but will switch to using AMD GPU for anything else.

MacOS uses paged VRAM (allocated form system memory) when using a IGPU's which means it only ever uses a max of 2GB (normally 1.5GB) ... thats why IGPU's have terrible gaming performance.

The fact that your system shows 7GB of VRAM for the IGPU is a complete mystery, it should not do that so something is not right, maybe a bug or issue in the BIOS.

Cheers
Jay

 

[iLikeHackintosh]

MacOs will only ever use a maximum of 2GB VRAM with a IGPU (in most cases 1.5GB)

But why it shows 7GB then? Anyway Gigabyte webpage says: "Maximum shared memory of 1 GB"

But seems to kinda work fine on headless mode..

 

[jaymonkey]

But why it shows 7GB then? Anyway Gigabyte webpage says: "Maximum shared memory of 1 GB" But seems to kinda work fine on headless mode..

@iLikeHackintosh,

I have no idea, thats why i mentioned it, first time i've ever seen or heard of MacOS reporting more than 2GB VRAM.

Cheers
Jay

 

[iLikeHackintosh]

@iLikeHackintosh,

I have no idea, thats why i mentioned it, first time i've ever seen or heard of MacOS reporting more than 2GB VRAM.

Cheers
Jay

I shall male live Linux USB and test machine on that, what it shows.

but this can be some kind of bug of this stats app too.

 

[Gigamaxx]

I shall male live Linux USB and test machine on that, what it shows.

but this can be some kind of bug of this stats app too.

I checked it out and intel does allow you to set high IGPU memory. They recommend 8gb System memory to set only 1gb IGPU allocation. So at 64gb System memory the max suggested would be 8gb at that rate.

 

[jaymonkey]

I checked it out and intel does allow you to set high IGPU memory. They recommend 8gb System memory to set only 1gb IGPU allocation. So at 64gb System memory the max suggested would be 8gb at that rate.

@Gigamaxx,

I'm pretty sure thats just for Windows and maybe Linux in that you can set a dedicated reserved amount of system ram to be used as VRAM.

MacOS handles the IGPU a bit different and will only use up to 1.5GB (or 2GB if you use the 2048MB VRAM patch) of system ram to be used as dedicated IGPU VARM.

If an app needs more (like a game needing to store textures) MacOS uses paged system memory, it more efficient in that it frees up more system ram when its not needed and only has a very slight hit on performance.

Cheers
Jay

 

[Gigamaxx]

@Gigamaxx,

I'm pretty sure thats just for Windows and maybe Linux in that you can set a dedicated reserved amount of system ram to be used as VRAM.

MacOS handles the IGPU a bit different and will only use up to 1.5GB (or 2GB if you use the 2048MB VRAM patch) of system ram to be used as dedicated IGPU VARM.

If an app needs more (like a game needing to store textures) MacOS uses paged system memory, it more efficient in that it frees up more system ram when its not needed and only has a very slight hit on performance.

Cheers
Jay

Yes I get it, but this is a bios setting for the intel to make it work. It could or should be set to 2gb max for OSX usage. Especially if you’re not using it as a sole gaming GPU in windows or Linux. It’s a waste of memory.

For macs they usually don’t come with a lot of memory at least for the laptops or iMacs that just have IGPU for graphics, unless you pay thousands for the upgrade lol.

 

[jaymonkey]

Yes I get it, but this is a bios setting for the intel to make it work. It could or should be set to 2gb max for OSX usage.

@Gigamaxx,

I don't think MacOs actually uses that BIOS setting, the MacOS kernel allocates system memory directly to the framebuffer kext. I think that BIOS setting only has an effect on Windows and Linux which need pre-allocated memory to use as VRAM for the IGPU.

At least that what i've found in all the testing i did a few years ago when i was doing research for the guides. On all the Hackintosh systems i've ever tested it on, it does not matter what you set that to MacOS does its own thing. Same is true for all genuine Mac's i've ever used ... (which is a lot).

However I have not tested it on a Coffee Lake Hackintosh system as i don't have one, so its possible that something strange is going on. The screen shot in post 502 is the first and only time iv'e ever seen or heard of MacOs reporting more than 2GB of VRAM for the IGPU.

Cheers
Jay

 

[Gigamaxx]

@Gigamaxx,

I don't think MacOs actually uses that BIOS setting, the MacOS kernel allocates system memory directly to the framebuffer kext. I think that BIOS setting only has an effect on Windows and Linux which need pre-allocated memory to use as VRAM for the IGPU.

At least that what i've found in all the testing i did a few years ago when i was doing research for the guides. On all the Hackintosh systems i've ever tested it on, it does not matter what you set that to MacOS does its own thing. Same is true for all genuine Mac's i've ever used ... (which is a lot).

However I have not tested it on a Coffee Lake Hackintosh system as i don't have one, so its possible that something strange is going on. The screen shot in post 502 is the first and only time iv'e ever seen or heard of MacOs reporting more than 2GB of VRAM for the IGPU.

Cheers
Jay

Yes I know it believe the same, what I was getting at is the OP should set bios allocation lower since it’s not likely used in OSX.

Testing it with Geekbench compute would show if it’s benfiting from more ram. Set to different ram allocations.