snes_ntsc_benchmark: 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/snes_ntsc_benchmark - from package: snes_ntsc-demos

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

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