0
votes
0answers
104 views

Ubuntu shows only one core out of four with nolapic booting option

I have a problem similar to one in http://ubuntuforums.org/showthread.php?t=1084622 http://ubuntuforums.org/showthread.php?t=1740798 http://ubuntuforums.org/showthread.php?t=1631926 i.e. my ubuntu ...
1
vote
3answers
549 views

Is having more CPU cores a better thing for running a web server?

I was reading about how User threads are mapped to kernel threads on Wikipedia. From this article I understand that FreeBSD uses the 1:1 (Kernel-level threading). So each User thread created by the ...
0
votes
1answer
76 views

old and proprietary java application crashes on multiple cores

I have to use StarTeam 2005 CrossPlatform Client on a recent debian system inside of a VM. This works fine, if the VM is configured to single-core. But if I configure multiple processors and/or ...
2
votes
1answer
191 views

How to interpret this /proc/cpuinfo data?

I'm using Intel Xeon E5-2620 processor. These are something I'm confusing about. I'm using Linux and in /proc/cpuinfo it says model name : Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz According to the ...
0
votes
1answer
115 views

Use all processor cores, 1 core/per 1 thread in *nix

According to xz documentation the "-T 4" means I should be using 4 threads, each compressing a different part of the file simultaneously. Before using nice -19 I would only get %50 usage of 1 core, ...
1
vote
1answer
65 views

How to know on which socket is a processor core?

I have a dual socket 8 core system, 4 cores on one socket and the other 4 cores on the other socket. How can I find, which core is on which socket through /proc/cpuinfo. For example here, on which ...
0
votes
2answers
445 views

Does running a dual-core processor with one core disabled reduce power consumption?

I have a Core 2 Duo laptop, and I want to extend my battery life as long as possible. If one was to use an uniprocessor kernel, the second core should not be 'booted' for use by the OS (for lack of ...
0
votes
1answer
173 views

Setting process affinity in Linux

In Windows, it is possible to make a program run on any number of cores in a multicore processor. It can be set in the Task Manager GUI. Likewise, Is it possible to set the process affinity in Linux, ...
14
votes
1answer
16k views

Why is the “top” command showing a CPU usage of 799%?

I am running a process in a 4 core Ubuntu server. However, top command shows that the CPU usage is 799% all the time. How can this be possible? I know for multi core CPUs, more than 100% CPU usage ...
1
vote
3answers
439 views

Will multicore allow the same CPU usage as multi CPU [duplicate]

Possible Duplicate: Multi-core CPU: can I say I have a 3x2.1GHz=6.3GHz CPU? I plan to buy latop with with i5-2410M processor that have 2 cores (according to spec it can also have 4 ...
-6
votes
1answer
147 views

“Steal” cores to other users: reduce user's processes priority

I'm working on a shared linux machine with multicores where I do have admin rights. Is it possible to freeze all the processes of other users (or give them less priority to access to the CPUs) so that ...
1
vote
0answers
759 views

Dynamically disabling cores in a power-efficient way?

I am looking for a mechanism to dynamically disable cores in Linux in order to minimize power consumption. Unfortunately, disabling cores using the following simple approach actually increases power, ...
4
votes
2answers
5k views

How to make commands in Mathematica 8 use all cores?

Many commands in Mathematica 8 (Integrate, Simplify, etc.) seem to only be using a single core on my system. Is there any way I can change the affinity so that it utilizes all cores for computations?
0
votes
1answer
89 views

Binding interface per core

I just wonder, is it possible (using Linux 2.6) to limit overhead done by ethernet interface to one specific core. Ie. I have core2duo CPU, and two ethernet interfaces: eth0 and eth1. Is it possible ...
3
votes
2answers
6k views

/proc/cpuinfo gives CPU info per core or per thread?

My CPU has 2 cores, so I can see two parts in /proc/cpuinfo. But, I want to know if CPUs that support Hyper-Threading (or similar tech), will /proc/cpuinfo give CPU info per core or per thread (or ...
7
votes
4answers
5k views

How do different Linux distributions handle multiple cores and multi-threading?

I realize that by asking this question I have already labeled myself as "unprepared" for high-performance workstations, but whatever, you have to start somewhere! I would like to know how different ...
2
votes
1answer
639 views

How to mitigate the multi-core “performance penalty”

I've been doing some computations at home and at work and have noticed some unexpected performance issues. The work machine is quite a bit more "serious" than the home machine, but sometimes the ...
2
votes
2answers
3k views

Multiple CPU cores in Virtual Box

When I was using Virtual Box in Windows 7, I could choose how many CPU cores to assign to the guest OS. Now I'm using Linux, and when I installed Virtual Box, I couldn't find that option. System ...
4
votes
2answers
3k views

Linux 'top' utility wildly inaccurate (more so for multi-CPU/core hardware)?

After using top for long time, albeit basically, I have grown to distrust its % CPU column reports. I have an 8-core (quad core Intel i7 920 with hyperthreading) hardware, and see some wild numbers ...
2
votes
2answers
570 views

Core i7 on linux loses its multithreading capability after suspend

On my debian-linux system, with a core i7 920 , each time I resume after the command "pm-suspend" (suspend to RAM), mutlithreading capabilities almost disappear. More specifically, two distinct ...
2
votes
3answers
1k views

In a multicore system, will each cpu have its own linux kernel?

What i meant was, in a multicore system with 'n' number of cpu's, will each cpu have its own linux kernel installed, or will all cpu's have a copy of the same kernel image? Another question ...
1
vote
6answers
3k views

Can Linux be run under Windows 7?

In Windows 7 if you have a multi-core processor you can run virtual machines. There is something called XP mode which lets you do a full XP install and lets you run XP just like the real thing, ...