Turbo boost limiting is supported on the Intel® and AMD® processors. Because processors have a high degree of variability in the amount of turbo boost each processor can supply, limiting the amount of turbo boost can reduce performance variability and reduce power consumption.
Turbo boost can be limited by setting the turbo_boost_limit kernel parameter to one of these values:
The following values are not supported in COS v1.4:
The limit applies only when a high number of cores are active. On a processor with N cores, the limit is in effect when the active core count is N, N-1, N-2, or N-3.
For example, on a 12-core processor, the limit is in effect when 12, 11, 10, or 9 cores are active.
Modify the Boot Orchestration Service (BOS) template for the node(s). This example below disables turbo boost. The default setting is 999 (no limit).
{
"boot_sets": {
"boot_set61": {
"boot_ordinal": "0",
"ims_image_id": "efdfe6fc-af3f-40f0-9053-dd1ad6c359d3",
"kernel_parameters": "console=tty0 console=ttyS0,115200n8 root=crayfs imagename=/SLES15 selinux=0 rd.shell rd.net.timeout.carrier=40 rd.retry=40 ip=dhcp rd.neednet=1 crashkernel=256M turbo_boost_limit=0",
"network": "nmn",
"node_groups": [
"group1",
"group2"
],
"node_list": [
"x0c0s28b0n0",
"node2",
"node3"
],
"node_roles_groups": [
"compute"
],
"rootfs_provider": "cpss3",
"rootfs_provider_passthrough": "dvs:api-gw-service-nmn.local:300:nmn0"
},
},
"cfs_branch": "my-test-branch",
"cfs_url": "https://api-gw-service-nmn.local/vcs/cray/config-management.git",
"enable_cfs": "true",
"name": "st6",
"partition": "p1"
}