RAM vs VRAM

[Ped]

Hi,

I'm going to be building a GPU farm with 4x 3090's.
In the guides on this site they advise getting 1.5 - 2 times the amount of RAM for the total amount of VRAM in the system.
For my situation, that would be 96GB VRAM. So do I need 144GB (realistically looking at a 256GB kit) of RAM?

Can anyone explain if this in fact is true, and why?

Thanks!

 

[Jerry James]

Hi,

I'm going to be building a GPU farm with 4x 3090's.
In the guides on this site they advise getting 1.5 - 2 times the amount of RAM for the total amount of VRAM in the system.
For my situation, that would be 96GB VRAM. So do I need 144GB (realistically looking at a 256GB kit) of RAM?

Can anyone explain if this in fact is true, and why?

Thanks!

VRAM doesn't really correlate with RAM in that way for most workloads. Could you quote what you read and link the article here? I'll take a look

https://www.cgdirector.com/how-much-vram-do-you-need/ - you'll find a table here with typical VRAM usage for different kinds of workloads. Of course, these requirements will go up as your scene increases in size and complexity.

 

[Ped]

VRAM doesn't really correlate with RAM in that way for most workloads. Could you quote what you read and link the article here? I'll take a look

https://www.cgdirector.com/how-much-vram-do-you-need/ - you'll find a table here with typical VRAM usage for different kinds of workloads. Of course, these requirements will go up as your scene increases in size and complexity.

Thanks! Yeah I read it here:

Best Hardware for GPU Rendering in Octane - Redshift - Vray (Updated)

Here's everything you need to know about the Best Hardware for GPU Rendering in Octane, Redshift, V-Ray and other modern GPU Render Engines.

www.cgdirector.com

It's the first bullet point in the "Best Memory (RAM) for GPU Rendering" section.

• To be safe, your RAM size should be at least 1.5 – 2x your combined VRAM size

 

[Jerry James]

Thanks! Yeah I read it here:

Best Hardware for GPU Rendering in Octane - Redshift - Vray (Updated)

Here's everything you need to know about the Best Hardware for GPU Rendering in Octane, Redshift, V-Ray and other modern GPU Render Engines.

www.cgdirector.com

It's the first bullet point in the "Best Memory (RAM) for GPU Rendering" section.

Oh I see. It's probably geared towards graphics cards that have 6-12 GB of RAM because if you have a scene that's loaded into your VRAM and it ends up being larger than your total system memory, it'll slow your PC down to a crawl when it loads from or loads back to system memory.

@Alex Glawion can probably shed more light on this.

 

[Ped]

Oh I see. It's probably geared towards graphics cards that have 6-12 GB of VRAM because if you have a scene that's loaded into your VRAM and it ends up being larger than your total system memory, it'll slow your PC down to a crawl when it loads from or loads back to system memory.

@Alex Glawion can probably shed more light on this.

Ah, I see! So there's no real direct relation. Good to know. Thanks very much