Intel confirms Arc GPUs must have AMD SAM / PCIe Resizable BAR for "optimal...

PCIe Resizable BAR for "optimal" performance

Arc Limited Edition

Intel, like it had promised, has begun the launch of its first-gen Arc Alchemist desktop GPUs starting with the entry-level A380. The company is promising a better value product compared to AMD and Nvidia's offerings at its expected price point.

As such, the company has also published a system requirements guide for system builders. The most interesting takeaway from it is that Intel Arc will need PCIe Resizable BAR (ReBAR) feature (also called Smart Access Memory or SAM in the case of AMD) enabled in the motherboard firmware for "optimal" performance. The firm has outlined the Intel processor families that will support Arc initially.

The document says:

Supported Hardware Configurations

Resizable BAR must be enabled for optimal performance in all applications using Intel® Arc™ A-Series Graphics. Initial support includes the following Intel®-based systems. Support for more platforms will be added at a later time:

CPU	Motherboard
12th Gen Intel® Core™ Processors	Intel 600 Series motherboard with Resizable BAR support enabled
11th Gen Intel® Core™ Processors 10th Gen Intel® Core™ Processors	Intel 500 Series motherboard with Resizable BAR support enabled Intel 400 Series motherboard with Resizable BAR support enabled

It is noteworthy here that a firmware update will be required if you wish to run an Arc A-series GPU like the recently released A380 on a 10th Gen Intel platform.

Intel has also hinted in the document that AMD Ryzen platforms with SAM available are also likely to be supported. It says:

Additional platforms/motherboards with Resizable BAR / Smart Access Memory enabled may also support Intel® Arc™ A-Series graphics.

This means you'd need a Ryzen 3000 series processor (not 3000 G-series APUs) and a 500-series motherboard for Arc GPUs to work optimally.

To set up ReBAR, go to motherboard firmware settings and enable the following:

• Above 4G Decoding (which will enable MMIO for 64-bit device for greater than 4GB memory address space)

• Re-Size BAR Support (The Resizable BAR option may be described as Re-Size BAR, Smart Access Memory, or Clever Access Memory)

Source: Intel