Fails to automatically detect Intel Xeon E7-4870 #94

zchothia opened this Issue Apr 23, 2012 · 3 comments


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Similar to issue #90, here are the details of another recent Intel processor which is not automatically detected. Output of the cpuid command is listed here, if additional details are necessary.



/tmp/OpenBLAS$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 47
model name      : Intel(R) Xeon(R) CPU E7- 4870  @ 2.40GHz
stepping        : 2
microcode       : 0x34
cpu MHz         : 2393.999
cache size      : 30720 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 11
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 syscall nx rdtscp lm constant_tsc up arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt aes hypervisor lahf_lm ida arat epb dts
bogomips        : 4787.99
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

I forgot to mention, I tried this with the latest commit from develop (74306b5).

@xianyi xianyi was assigned Apr 23, 2012

Hi Zaheer,

I added this CPU detection.
Please test it on develop branch.




Excellent, it now works fine so this issue can be closed.

I should remark that NUM_CORES is incorrectly detected as 1, but I suspect that may be due to the combination of a recent processor and outdated library/kernel:

$ uname -a
Linux dev3vrt 3.2.7-1.fc16.x86_64 #1 SMP Tue Feb 21 01:40:47 UTC 2012 x86_64 x86 _64 x86_64 GNU/Linux
$ python
Python 2.7.2 (default, Oct 27 2011, 01:40:22)
[GCC 4.6.1 20111003 (Red Hat 4.6.1-10)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes
>>> libc = ctypes.cdll.LoadLibrary('')
>>> libc.get_nprocs()
@zchothia zchothia closed this Apr 23, 2012
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