[Info-vax] Disable hyper-threading from the DCL prompt

[Michael Moroney]

RGB <11brvo at gmail.com> writes:

>Hi all,

>We have several x2800 i2's running VMS v8.4 and I seem to recall a command,=
> issued from the DCL prompt, which disables hyper-threading at the CPU's.  =
>I know there is another way to do so from EFI but I thought it was also pos=
>sible to do so from DCL.  (Knowing that it will not take effect until the n=
>ext reboot.)

>Can someone please refresh my feeble mind as to the command?

>Thanks in advance.

$ hthreads :== $SYS$COMMON:[SYSTEST]hthreads
$ hthreads help

You should try both ways to see if threads help or hurt.  CPU-intensive
jobs that run in parallel tend to be helped by threads.  Systems where 
there is a lot of contention for spinlocks (heavy I/O, locks in clusters
etc) can be hurt by them.