Hyperthreading?

[don250r]

I have a i5-2500K.
http://ark.intel.com/products/52210/Int ... o-3_70-GHz.

I also have an Acer Aspire one with the intel N455 processor.
http://ark.intel.com/products/49491/Int ... 4#p1153064

I have been following this thread:
viewtopic.php?p=1153064#p1153064.

And out of curiosity i ran on my desktop

Code: Select all

 $ cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 42
model name	: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
stepping	: 7
microcode	: 0x28
cpu MHz		: 1688.285
cache size	: 6144 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 4
apicid		: 0
initial apicid	: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt tsc_deadline_timer aes xsave avx lahf_lm epb tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts
bugs		:
bogomips	: 6799.35
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 42
model name	: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
stepping	: 7
microcode	: 0x28
cpu MHz		: 1613.132
cache size	: 6144 KB
physical id	: 0
siblings	: 4
core id		: 1
cpu cores	: 4
apicid		: 2
initial apicid	: 2
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt tsc_deadline_timer aes xsave avx lahf_lm epb tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts
bugs		:
bogomips	: 6799.35
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 2
vendor_id	: GenuineIntel
cpu family	: 6
model		: 42
model name	: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
stepping	: 7
microcode	: 0x28
cpu MHz		: 1694.214
cache size	: 6144 KB
physical id	: 0
siblings	: 4
core id		: 2
cpu cores	: 4
apicid		: 4
initial apicid	: 4
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt tsc_deadline_timer aes xsave avx lahf_lm epb tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts
bugs		:
bogomips	: 6799.35
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 42
model name	: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
stepping	: 7
microcode	: 0x28
cpu MHz		: 1626.796
cache size	: 6144 KB
physical id	: 0
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 6
initial apicid	: 6
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt tsc_deadline_timer aes xsave avx lahf_lm epb tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts
bugs		:
bogomips	: 6799.35
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

Curious, the i5 has an HT flag...

[xenopeek]

That flag tells you that the processor is hyperthreading capable, not that hyperthreading is actually enabled. If your i5 processor was sold as an i7, it would actually also come with hyperthreading enabled but both i5 and i7 have the logic on the chip die.

To check whether hyperthreading is actually enabled you can use lscpu and check this line in the output:

Code: Select all

Thread(s) per core:    1

If "Thread(s) per core" is 2, you have hyperthreading enabled in your processor.

[LinuxJim]

My i5 has hyperthreading enabled:

Code: Select all

$ lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    2
Core(s) per socket:    2
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 69
Model name:            Intel(R) Core(TM) i5-4210U CPU @ 1.70GHz
Stepping:              1
CPU MHz:               2405.156
CPU max MHz:           2700.0000
CPU min MHz:           800.0000
BogoMIPS:              4788.79
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              3072K
NUMA node0 CPU(s):     0-3
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 syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm ida arat epb pln pts dtherm tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt

[xenopeek]

I was comparing i5-2500k vs i7-2600k. But yes, your i5-4210u has hyperthreading. That's to make up for only having two cores. The cheaper i3-4010U is basically the same processor but has hyperthreading disabled, though it will likely also show it as hyperthreading capable in the cpu flags (as the logic is on the chip die, just not enabled).

[LinuxJim]

I was comparing i5-2500k vs i7-2600k. But yes, your i5-4210u has hyperthreading.

Ahhh, got it.

[don250r]

Ahh,,, i got it
1 thread per core here.
Here is another oddity, BIOS says 47 * 103 BCLOCK = 4.8Ghz
cpuinfo again, running prime95

Code: Select all

cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 42
model name	: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
stepping	: 7
microcode	: 0x28
cpu MHz		: 4699.921
cache size	: 6144 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 4
apicid		: 0
initial apicid	: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 popcnt tsc_deadline_timer aes xsave avx lahf_lm epb tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts
bugs		:
bogomips	: 6799.35
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

4.7Ghz....

[LinuxJim]

Here is another oddity, BIOS says 47 * 103 BCLOCK = 4.8Ghz

Your CPU is rated to run at 3.3 GHz continuous duty. /proc/cpuinfo shows that it is currently running at 4699.921 MHz. The 'lscpu' command will show you the minimum and maximum speed limits for your particular CPU.

[don250r]

In the BIOS it shows 4841 MHz. In Windows(ugh) CPU-Z shows 4841.
cpuinfo and lscpu in LM shows ~4700, like its not counting the 103 BCLOCK.
Just an idle curiosity, at over 4 GHz i dont think 100MHz matters too much

[don250r]

I was disappointed in my Cpus Overclocking performance.
I went straight for 5GHz and crashed it several times.
Went back to a what I call a super stable 4.8.
Prime95, Rhythmbox, forums running at same time.
Took a tiny bit more voltage for stable LM vs win10
But as is well
EDIT: an an additional terminal installing new apps,
I like super swamping the cpu for stress tests

[z31fanatic]

Your desktop i5-2500k processor is quad core but has no hyperthreadding. Mobile i5 processors are dual core with hyperthreading (though some Skylake mobile i5 are now quad with no hyperthreading)

For your processor generation it went like this
desktop and mobile i3 - both dual core with hyperthreading
desktop i5 - quad core no hyperthreading
mobile i5 - dual core with hyperthreading
mobile i7 - dual or quad core and both with hyperthreading
desktop i7 - quad core with hyperthreading