Why Isn't Linux Fully MultiProcessor Ready?

[Ravernomina]

As the Top Says Its something that bothered me for awhile. Why Linux Cannot Seem to thread a CPU task well. Take OS X for example. If i have 3 apps going my CPU on both cores stay the same, both doing the same amount of work as the other. On Linux One is going crazy and the other one isn't doing much. Why is this, Not trying to seem like a brat or anything, but i never understood that. I mean a Multi-cored CPU should have the kernel, drivers, libraries, and Extensions all multi-Core Ready. Some one Explain... Express your opinion.

[Rhubarb]

It really depends what workload you're giving it.
For instance, if you're doing a lot of heavy stuff in firefox, it'll only consume 1 core, because firefox is simply not coded (yet) to support multiple cores.

There are many many apps that'll only work on the 1 core, while there are only a few that support multiple cores.

Some multi-core supporting apps:
make - by default compiling only uses 1 core, but if you use the -j2 option it'll compile with 2 cores.
x264 - great codec for encoding videos, and supports 1 or many cores which you have to specify to get the performance boost.

Some apps just aren't well suited for multicore use.

Another thing that is noteworthy, is that apple has recently released Grand Central Dispatch as open source, so it's now possible to integrate this into Linux systems as well.

On a related note, Linux is used for many of the world's top super computers, where they have thousands of CPUs - but these systems run customised applications on a customised linux distro.

To sum up, if you run the same applications on your Mac as you do in Ubuntu, there really shouldn't be that much of a difference in CPU work loads.

[Ravernomina]

It really depends what workload you're giving it.
For instance, if you're doing a lot of heavy stuff in firefox, it'll only consume 1 core, because firefox is simply not coded (yet) to support multiple cores.

There are many many apps that'll only work on the 1 core, while there are only a few that support multiple cores.

Some multi-core supporting apps:
make - by default compiling only uses 1 core, but if you use the -j2 option it'll compile with 2 cores.
x264 - great codec for encoding videos, and supports 1 or many cores which you have to specify to get the performance boost.

Some apps just aren't well suited for multicore use.

Another thing that is noteworthy, is that apple has recently released Grand Central Dispatch as open source, so it's now possible to integrate this into Linux systems as well.

On a related note, Linux is used for many of the world's top super computers, where they have thousands of CPUs - but these systems run customised applications on a customised linux distro.

To sum up, if you run the same applications on your Mac as you do in Ubuntu, there really shouldn't be that much of a difference in CPU work loads.

But there is... My OS X is Handling Apps better then Linux.... and thats saying something

[3rdalbum]

But there is... My OS X is Handling Apps better then Linux.... and thats saying something

Maybe the difference is that Mac OS X is running less efficiently than Linux, and so it's putting heavy load into three cores to perform the same work accomplished by one core on Linux.

Programs must be specifically written to split their work across multiple threads, and therefore across multiple cores. Either you can use these specially-written programs, or you can run multiple intensive programs at the same time.

Some programs use a hybrid approach - for instance, an MP3 encoder algorithm can only use one thread at a time, and some video encoder algorithms are the same. Some programs like SoundConverter and Blacklight will encode multiple files simultaneously, and each file's encoding job will automatically be assigned to a different core.

[Ravernomina]

Maybe the difference is that Mac OS X is running less efficiently than Linux, and so it's putting heavy load into three cores to perform the same work accomplished by one core on Linux.

Programs must be specifically written to split their work across multiple threads, and therefore across multiple cores. Either you can use these specially-written programs, or you can run multiple intensive programs at the same time.

Some programs use a hybrid approach - for instance, an MP3 encoder algorithm can only use one thread at a time, and some video encoder algorithms are the same. Some programs like SoundConverter and Blacklight will encode multiple files simultaneously, and each file's encoding job will automatically be assigned to a different core.

Um not not really.... im running WOW, and flash and their both using my CPU at 25% each... on Linux It runs 100%

[murderslastcrow]

On the same computer?

[Ravernomina]

On the same computer?

Yes

[Psumi]

Is your processors by any chance lower than or equal to 2 GHz?

If so, then that's your problem. Flash takes up a CONSIDERABLE amount of CPU in linux (in comparison to Windows), and the recommended spec from adobe (not minimum) is 2 GHz for one core, doing nothing else but flash. (as well as 64 MB of Video Memory.)

[szymon_g]

If so, then that's your problem. Flash takes up a CONSIDERABLE amount of CPU in linux (in comparison to Windows), and the recommended spec from adobe (not minimum) is 2 GHz for one core, doing nothing else but flash. (as well as 64 MB of Video Memory.)

lol. and people say that linux is better for older computers

but ad rem: linux is multiprocessor ready from it's beginning- but, saying that, i mean some usefull programs, like databases, webservers, mailservers etc- not a typical desktop applications

[markp1989]

lol. and people say that linux is better for older computers

flash isnt the linux devs responsibility, adobe really need to pull there finger out and sort it out, its been bad as long as i remember