Klaus Kaempf wrote:

Hmm, the "flags" line shows 'ht' so this CPU should have hyperthreading.

I have a Celeron that reports hyperthreading too: # cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 3 model name : Intel(R) Celeron(R) CPU 2.40GHz stepping : 4 [snip] fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc pni monitor ds_cpl cid xtpr bogomips : 4792.73 I'm not sure what the proper interpretation of the 'ht' flag should be. It also reports SSE2 which I didn't think Celerons support? /Per Jessen, Zürich -- ENIDAN Technologies GmbH - managed email-security. Is _your_ business under attack? http://www.spamchek.com/ --------------------------------------------------------------------- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org

Robert Love wrote:

On Wed, 2007-01-17 at 20:50 +0100, Per Jessen wrote:

...

I'm not sure what the proper interpretation of the 'ht' flag should be. It also reports SSE2 which I didn't think Celerons support?

The HT bit simply means that the processor supports hyper-threading, not that it physically has multiple virtual cores.

So, does my Celeron processor support hyperthreading? I'm fairly certain it does not, which is why the HT flag seems to be misplaced.

To programmatically see if a chip physically has HT cores, you have to look at the "physical id" and "core id" fields. And the Prescott-based Celeron D family, such as yours, supports SSE 2 and 3.

Ah, interesting. How do you tell from my cpuinfo that it is a Celeron D? And is there an SSE3 indicator/flag? /Per Jessen, Zürich -- ENIDAN Technologies GmbH - managed email-security. Starting at SFr1/month/user - http://www.spamchek.com/ --------------------------------------------------------------------- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org

On 1/17/07, Robert Love wrote:

On Wed, 2007-01-17 at 21:23 +0100, Per Jessen wrote:

...

So, does my Celeron processor support hyperthreading? I'm fairly certain it does not, which is why the HT flag seems to be misplaced.

Your processor does support hyperthreading, architecturally speaking, hence the HT flag. But you have only one virtual core. So for all practical purposes, your chip is not hyperthreaded.

...

...

To programmatically see if a chip physically has HT cores, you have to look at the "physical id" and "core id" fields. And the Prescott-based Celeron D family, such as yours, supports SSE 2 and 3.

Ah, interesting. How do you tell from my cpuinfo that it is a Celeron D?

Just from the name and the speed and the other flags.

...

And is there an SSE3 indicator/flag?

Yes, PNI (stands for Prescott New Instructions).

Robert hey fellows and gals, this confuses me to no end.<sigh>

here is my cat /proc/info processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 3 model name : Intel(R) Pentium(R) 4 CPU 2.80GHz stepping : 4 cpu MHz : 2806.601 cache size : 1024 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 3 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc pni monitor ds_cpl cid xtpr bogomips : 5616.79 processor : 1 vendor_id : GenuineIntel cpu family : 15 model : 3 model name : Intel(R) Pentium(R) 4 CPU 2.80GHz stepping : 4 cpu MHz : 2806.601 cache size : 1024 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 3 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc pni monitor ds_cpl cid xtpr bogomips : 5613.15 It sure looks like I have 2 processors. What say you?

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Randall R Schulz wrote:

...

It sure looks like I have 2 processors.

Yes, it does. What's the problem?

...

What say you?

What's the question?

The second processor is not a real processor, it is simply a virtual processor used by the hyperthreading abilities of the whole CPU. -Ted --------------------------------------------------------------------- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org

Robert Love wrote:

Your processor does support hyperthreading, architecturally speaking, hence the HT flag. But you have only one virtual core. So for all practical purposes, your chip is not hyperthreaded.

This is where I get lost - AFAIK, a Pentium 4 with hyperthreading still only has one core/CPU/execution unit. It has duplicate storage for processor state, and uses some clever magic stuff to do some limited concurrent execution. In Linux this is represented as a 2nd CPU. The Celeron is a cut-back/restricted version of the P4 - less cache, and no clever/magic hyperthreading. With or without a virtual core. This is why I think it is odd for it to indicate HT supported, but never mind. /Per Jessen, Zürich -- ENIDAN Technologies GmbH - managed email-security. Is _your_ business under attack? http://www.spamchek.com/ --------------------------------------------------------------------- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org