Reg file will suffice, you can use software - but it's like hammer a nail with microscope. Registry address is [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000] 0000 for first gpu, 0001 for second and so on, keyname and value - "KMD_EnableInternalLargePage"=dword:00000002. Regfile for 3 gpus (hope you can adapt for you needs):
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000]
"KMD_EnableInternalLargePage"=dword:00000002
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0001]
"KMD_EnableInternalLargePage"=dword:00000002
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0002]
"KMD_EnableInternalLargePage"=dword:00000002
If you can't use reg script for w/e reason - here is
link for software by Paedy.