Uncertain if quad-core processor recognised

**blueridgedog** · February 8th, 2009

My concern is this is not something that is particular to the systems listed, but may be more general for specific CPUs or kernel versions. Perhaps some other members will chime in with reports of support for their quad core CPUs.

**bapoumba** · February 8th, 2009

Moved to hardware (thanks blueridgedog

)

**walawa** · February 8th, 2009

I tried booting with noapic and then with acpi=off at the end of the kernel line, but it did not make a difference.

This is the output of dmesg | grep -i cpu:

Code:

[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] SMP: Allowing 1 CPUs, 0 hotplug CPUs
[    0.000000] PERCPU: Allocating 41628 bytes of per cpu data
[    0.000000] NR_CPUS: 64, nr_cpu_ids: 1, nr_node_ids 1
[    0.000000] Initializing CPU#0
[    0.004000] SLUB: Genslabs=12, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.004189] Initializing cgroup subsys cpuacct
[    0.004202] CPU: L1 I cache: 32K, L1 D cache: 32K
[    0.004205] CPU: L2 cache: 4096K
[    0.004207] CPU: Physical Processor ID: 0
[    0.004208] CPU: Processor Core ID: 0
[    0.024039] weird, boot CPU (#0) not listedby the BIOS.
[    0.132067] Brought up 1 CPUs
[    0.132078] CPU0 attaching sched-domain:
[    0.132080]  domain 0: span 0 level CPU
[    1.116669] cpuidle: using governor ladder
[    1.116671] cpuidle: using governor menu

Could the line that says "SMP: Allowing 1 CPUs, 0 hotplug CPUs" have anything to do with the problem?

**blueridgedog** · February 9th, 2009

Perhaps it is certain Bios(es) and certain CPU's that the kernal has trouble with?

**unutbu** · February 9th, 2009

I agree with blueridgedog. Please run

Code:

sudo lshw | bzip2 -c > lshw.bz2

and attach lshw.bz2 to a post so we'll know the make/model of your machine, motherboard, bios, and cpus.

Googling any of those keywords along with "SMP Allowing 1 CPUs" or "weird, boot CPU (#0) not listedby the BIOS" might also be useful.

**ectospasm** · February 9th, 2009

Originally Posted by blueridgedog

Perhaps it is certain Bios(es) and certain CPU's that the kernal has trouble with?

In that case I'd expect it to be consistent, that it would either recognize or fail to recognize all four of my cores 100% of the time. For me at least, I'm guessing that it fails to recognize all four cores about 85% of the time. Right now, I'm in a boot that sees all four cores. If I reboot, I suspect only one core will come up.

**anv** · February 9th, 2009

Sorry to disturb, but I noticed exactly same behavior on my AMD quad-core processor this was my original question:

http://ubuntuforums.org/showthread.php?t=1060923

but as I did some of those first steps in this section, I noticed also that it gives just one cpu. but one thing also as I noticed while doing renderings and following the system from Htop if I stopped and continued it took core 3 instead of the core 4

**unutbu** · February 9th, 2009

For what it's worth, here is a testimonial that the Core 2 Quad Q6600 processor is compatible with Ubuntu 8.10 (both 32- and 64-bit):
https://lists.ubuntu.com/archives/ub...ry/170329.html

**blueridgedog** · February 9th, 2009

One has to wonder if the author of that post actually verified that all four cores were running rather than the system working. I am ordering a quad core this week, so soon I will have another statistic to add to the issue.

**walawa** · February 10th, 2009

The output of "sudo lshw | bzip2 -c > lshw.bz2" is attached to this post.

Does ubuntu 8.10 use the 386 or 686 kernel? I've read that 686 is better for Intel processors. Is this true?