4 CPU's shown in top and /proc/cpuinfo

Kristijan · 01-20-2005, 09:28 PM

Hi,

I don't have physical access to the box, but I need to find out how many CPU's it has. Both top and /proc/cpuinfo show 4 CPU's, which I know isn't the case.

I google'd around and read something about hyperthreading being enabled, and this causing 4 CPU's being shown. Since I don't have physical access to the box, I can't disable hyperthreading in the BIOS.

Is there any other way to find out for sure how many CPU's are in the box?

Cheers,
-Kristijan

AltF4 · 01-20-2005, 09:31 PM

Code:

cat /proc/cpuinfo

might produce the infos you need :-)

Kristijan · 01-20-2005, 09:33 PM

AltF4,

As the heading states, /proc/cpuinfo shows that I have 4 CPU's, even though I don't.

Thanks,
-Kristijan

btmiller · 01-20-2005, 10:03 PM

Do you have 2 hyperthreading CPUs then? Each hyperthreading CPU will show up as two CPUs. Newer Xeons and P4s have hyperthreading characteristics, but if you have 2 they must be Xeons since AFAIK P4s can't dpo SMP configurations.

AltF4 · 01-25-2005, 06:44 PM

my non-xeon p4 does "smp" nicely

1 P4 showing up as 2 CPUs

ironwalker · 01-25-2005, 07:54 PM

Regular P4's do smp.

The OP must have dual Hyper threaded cpu's as already stated above.
Im useing dual xeon with hyper threading and it shows as 4 cpu's as it should.

guzzi · 01-25-2005, 08:09 PM

with the 2.4 series kernels, you control how many cpu's are there by how the kernel is compiled.

In processor type and features of config SMP = y will get HT going for at least 2

in general setup ACPI= y will get four if thats what you have. Where a ACPI = n will get you only 2

Have done a bunch of experimenting with 2.4 and from my initial look at 2.6, there are not as many gotchas.