What is "Graphics Video Max Memory" and its impact on OpenCL?

[allanmac1]

I noticed today's announced desktop and server Broadwell CPU's have very different "Graphics Video Max Memory" attributes.

Can someone from Intel explain how to interpret the "Graphics Video Max Memory" attribute and whether it impacts the HD Graphics OpenCL environment?  

Is this just a limit for rendering surfaces addressable by QuickSync and the IGP?

Here's the comparison on ARK:

[Robert_I_Intel]

Hi Allan,

Things are clearer now: there is a bug in the documentation on ARK, which we are working to correct.

These are not HW limits—ARK team seems to have done a pick-and-choose from Windows Driver PRD without stating the limits’ contexts. For example, 1.7GB is Win7 driver’s limit—We support more on Win8/8.1. But all these numbers are N/A for Win10 (and other OS’s like OS X, Linux, etc), where the max could be as high as the HW limit of 256TB (2⁴⁸).

Documentation will be fixed as follows:

Graphics Video Max Memory à Graphics Memory Addressability

1.7GB/16GB à 256 TB†

† Subject to OS and graphics driver limitations.

[allanmac1]

Excellent, that's good news.

[Carlos_C_5]

Hi Intel Technician Team

Will the same as above is applicable to the new Intel Mobile Xeon chips?

These comments (shown below) as per your response to the other user on the Thu, 06/04/2015 - 11:58  are also applicable to these news chips?

"These are not HW limits—ARK team seems to have done a pick-and-choose from Windows Driver PRD without stating the limits’ contexts. For example, 1.7GB is Win7 driver’s limit—We support more on Win8/8.1. But all these numbers are N/A for Win10 (and other OS’s like OS X, Linux, etc), where the max could be as high as the HW limit of 256TB (248)."

[Robert_I_Intel]

Hi Carlos, here are some details:

Correct numbers for Windows 10 are here:

http://www.intel.com/content/www/us/en/support/graphics-drivers/000020962.html

Windows 8 the restrictions are more muddier like:

Available GFX memory (not OpenCL MAX_MEM Per buffer) = min (RAM/2, ~3900MB) à client based platforms etc.

Server based SKUs/Oss its different equation:

Available GFX memory (not OpenCL MAX_MEM Per buffer) = min (RAM/2, ~16GB)

See this page for windows 8.

http://www.intel.com/content/www/us/en/support/graphics-drivers/000005539.html

And this page for windows 7:

http://www.intel.com/content/www/us/en/support/processors/000005472.html

[Vishal_R_]

I just bought new processor i5-4460 .Specification says that it's graphics video max memory is 2GB, does that mean I can't use 4GB Graphics card , if I will use it will use only 2GB of 4GB?

[Robert_I_Intel]

Hi Vishal,

Here is the definition of Graphics Video Max Memory:

The maximum amount of memory accessible to processor graphics. Processor graphics operates on the same physical memory as the CPU (subject to OS, driver, and other system limitations).

This is the portion of your DRAM accessible by Intel Processor Graphics. Does not affect discrete graphics cards.