intel_disable_clock_gating: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/intel_disable_clock_gating - from package: intel-gpu-tools

You may install the required package with command yum install {package}

Error in other languages:
intel_disable_clock_gating: bevel nie gevind nie
intel_disable_clock_gating: comandă negăsită
intel_disable_clock_gating: comando não encontrado
intel_disable_clock_gating: commande introuvable
intel_disable_clock_gating: command not found
intel_disable_clock_gating: käsku ei ole
intel_disable_clock_gating: không tìm thấy lệnh
intel_disable_clock_gating: komanda nerasta
intel_disable_clock_gating: Kommando nicht gefunden.
intel_disable_clock_gating: kommandot finns inte
intel_disable_clock_gating: komut yok
intel_disable_clock_gating: nie znaleziono polecenia
intel_disable_clock_gating: níor aimsíodh an t-ordú
intel_disable_clock_gating: no se encontró la orden
intel_disable_clock_gating: no s'ha trobat l'ordre
intel_disable_clock_gating: opdracht niet gevonden
intel_disable_clock_gating: parancs nem található
intel_disable_clock_gating: perintah tidak ditemukan
intel_disable_clock_gating: príkaz nenájdený
intel_disable_clock_gating: příkaz nenalezen
intel_disable_clock_gating: команда не найдена
intel_disable_clock_gating: командата не е открита
intel_disable_clock_gating: 命令找不到
intel_disable_clock_gating: コマンドが見つかりません