HCCL_INTRA_PCIE_ENABLE

Description

Specifies whether to use the PCIe link for communication on a server.

The default value of this environment variable is 1. It can be configured separately or used together with the environment variable HCCL_INTRA_ROCE_ENABLE. The following table lists the supported configuration combinations and the intra-server communication links adopted under each combination.

**Table 1** Configuration combinations supported by HCCL_INTRA_PCIE_ENABLE and HCCL_INTRA_ROCE_ENABLE
HCCL_INTRA_PCIE_ENABLE	HCCL_INTRA_ROCE_ENABLE	Intra-Server Communication Link
1	Not configured	PCIe
1	0	PCIe
0	1	RoCE
Not configured	1	RoCE
0	0	PCIe
Not configured	Not configured	PCIe

HCCL_INTRA_PCIE_ENABLE and HCCL_INTRA_ROCE_ENABLE cannot be set to 1 at the same time.
If HCCL_INTRA_PCIE_ENABLE is set to 0, HCCL_INTRA_ROCE_ENABLE must be configured.
If HCCL_INTRA_PCIE_ENABLE is not configured, HCCL_INTRA_ROCE_ENABLE must not be set to 0.

Example

export HCCL_INTRA_PCIE_ENABLE=1

Constraints

The Atlas 200T A2 Box16 heterogeneous subrack has two modules on the left and right: devices 0 to 7 and devices 8 to 15. For this product:

In the single-server scenario, when the server uses a PCIe link for internal communication, if the devices from two modules are required simultaneously, both modules must have the same number of devices and be on the same plane, meaning that devices 0 and 8, 1 and 9 (and so on) must be used together. When the server uses a RoCE link for internal communication, there is no such restriction.

Applicability

Atlas training product: Only the Atlas 300T Pro training card with this processor model is supported.

Atlas A2 training product/Atlas A2 inference product: Only the Atlas 200T A2 Box16 heterogeneous subrack with this processor model is supported.

Parent topic: Function