Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
Kernel options for later Intel CPU's [SOLVED]
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Kernel & Hardware
View previous topic :: View next topic  
Author Message
Tony0945
Advocate
Advocate


Joined: 25 Jul 2006
Posts: 3294
Location: Illinois, USA

PostPosted: Tue Jan 12, 2016 7:48 pm    Post subject: Kernel options for later Intel CPU's [SOLVED] Reply with quote

I'm running AMD k8 & K10 but considering Intel (to save power). I noticed that the kernel has only these two options:

Intel P4/Netburst (netburst?) Optimize for Intel Pentium 4, Pentium D and older Nocona/Dempsey │
│ Xeon CPUs with Intel 64bit which is compatible with x86-64. │
│ Note that the latest Xeons (Xeon 51xx and 53xx) are not based on the │
│ Netburst core and shouldn't use this option. You can distinguish them │
│ using the cpu family field │
│ in /proc/cpuinfo. Family 15 is an older Xeon, Family 6 a newer one.

And:
Core2/ Newer Xeon │
│ Select this for Intel Core 2 and newer Core 2 Xeons (Xeon 51xx and │
│ 53xx) CPUs. You can distinguish newer from older Xeons by the CPU │
│ family in /proc/cpuinfo. Newer ones have 6 and older ones 15 │
│ (not a typo)

This stuff sounds ancient. What about non-Xeon's? Haswell, Devil's canyon, Skylake? I've seen Xeons in industrial equipment but everyone else I know has a non-Xeon.

Should I stick with AMD for a pure Gentoo system despite their throwing heat like a blowtorch? Or are experimental options to use later features in the works?


Last edited by Tony0945 on Fri Jan 15, 2016 8:56 pm; edited 1 time in total
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 44171
Location: 56N 3W

PostPosted: Tue Jan 12, 2016 8:27 pm    Post subject: Reply with quote

Tony0945,

There is a patch, a patch set even. emerge gentoo-sources with the experimental USE flag.
I've not kept up with what that gives you, so you need to do some reading.

As usual, if it breaks, you can keep all the pieces.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
geki
Advocate
Advocate


Joined: 13 May 2004
Posts: 2325
Location: Germania

PostPosted: Tue Jan 12, 2016 8:46 pm    Post subject: Reply with quote

Just wondering.

Do you want to save power and therefore enable power saving options?
Or do you want to change the march flag for gcc?

The selection you mention does not save power, neither would a patch for other cpus to that selection.
_________________
boost|select libs to build|slotable|python-buildid

hear hear
Back to top
View user's profile Send private message
Tony0945
Advocate
Advocate


Joined: 25 Jul 2006
Posts: 3294
Location: Illinois, USA

PostPosted: Tue Jan 12, 2016 11:20 pm    Post subject: Reply with quote

Thanks Neddy!

Geki: The Intel high performance CPU's take 91 watts, the AMD 220 watts. I have enough problems with ComEd complaining that my electricity usage is too high. Yes, I use the cpufreq module (I forget the name), it cuts my present CPU's power from 125W to 60 watts at idle at quarter speed.
What I'd really like is something like my old k6-3+ system that takes 40W TOTAL, but I realize that's impossible, especially since I have three hard drives.

I don't actually have an Intel system yet, I'm exploring options.
Back to top
View user's profile Send private message
Tony0945
Advocate
Advocate


Joined: 25 Jul 2006
Posts: 3294
Location: Illinois, USA

PostPosted: Wed Jan 13, 2016 2:23 am    Post subject: Reply with quote

NeddySeagoon wrote:
Tony0945,

There is a patch, a patch set even. emerge gentoo-sources with the experimental USE flag.
I've not kept up with what that gives you, so you need to do some reading.

As usual, if it breaks, you can keep all the pieces.


I set the flag and not only does it give many more intel options including Core i7, but it now shows a separate option for K-10/Athlon II/Phenom II, which I am in the process of compiling now.
Back to top
View user's profile Send private message
geki
Advocate
Advocate


Joined: 13 May 2004
Posts: 2325
Location: Germania

PostPosted: Wed Jan 13, 2016 6:50 am    Post subject: Reply with quote

My Intel i5 4-core system has 45W TDP (MAX power). The Intel T-series have low power consumption. IIRC, U-series was even lower, I may be wrong.
Though, are not the fastest ones. However your needs are. Mine is power consumption.
Code:
$ uname -a
Linux ana 4.3.3-gentoo #1 SMP PREEMPT Mon Dec 28 01:36:37 CET 2015 x86_64 Intel(R) Core(TM) i5-2500T CPU @ 2.30GHz GenuineIntel GNU/Linux

_________________
boost|select libs to build|slotable|python-buildid

hear hear
Back to top
View user's profile Send private message
toralf
Developer
Developer


Joined: 01 Feb 2004
Posts: 3723
Location: Hamburg

PostPosted: Wed Jan 13, 2016 8:46 am    Post subject: Reply with quote

Did you tried the ondemand governor of the kernel ? Works fine here (at Intel processors) since years.
Back to top
View user's profile Send private message
Syl20
Guru
Guru


Joined: 04 Aug 2005
Posts: 564
Location: France

PostPosted: Wed Jan 13, 2016 11:12 am    Post subject: Re: Kernel options for later Intel CPU's Reply with quote

Tony0945 wrote:
Core2/ Newer Xeon │
│ Select this for Intel Core 2 and newer Core 2 Xeons (Xeon 51xx and │
│ 53xx) CPUs. You can distinguish newer from older Xeons by the CPU │
│ family in /proc/cpuinfo. Newer ones have 6 and older ones 15 │
│ (not a typo)

This stuff sounds ancient. What about non-Xeon's? Haswell, Devil's canyon, Skylake?

With this option, the kernel works well with all the Core2 and later Intel CPUs I own, including a Haswell one. Maybe experimental options provide better optimizations, but I didn't feel needing them yet. One day, I'll try...
The ondemand governor does the job.
Back to top
View user's profile Send private message
chithanh
Developer
Developer


Joined: 05 Aug 2006
Posts: 2152
Location: Berlin, Germany

PostPosted: Wed Jan 13, 2016 1:15 pm    Post subject: Reply with quote

Nowadays for modern Intel CPUs it is mostly recommended to stay with the performance governor, and delegete power management to the intel_pstate driver instead.
Back to top
View user's profile Send private message
1clue
Advocate
Advocate


Joined: 05 Feb 2006
Posts: 2562

PostPosted: Wed Jan 13, 2016 3:18 pm    Post subject: Reply with quote

I have a communications-oriented 8-core Atom c2758 that advertises 20w tdp, and while it's not nearly as fast at compilation as an old i7 920 it's actually faster at compression and a few other things. Not sure what it actually uses since I don't have a power meter.

I use core2 and the experimental flags, can't remember exactly what. Works fine. Use march=native.
Back to top
View user's profile Send private message
Buffoon
Veteran
Veteran


Joined: 17 Jun 2015
Posts: 1074
Location: EU or US

PostPosted: Wed Jan 13, 2016 3:49 pm    Post subject: Reply with quote

Code:

 │                                                                                                         
 │                                 AMD Opteron/Athlon64/Hammer/K8                     
 │                                 AMD Opteron/Athlon64/Hammer/K8 with SSE3       
 │                                 AMD 61xx/7x50/PhenomX3/X4/II/K10                   
 │                                 AMD Barcelona                                                   
 │                                 AMD Bobcat                                                       
 │                                 AMD Bulldozer                                                     
 │                                 AMD Piledriver                                                     
 │                                 AMD Jaguar                                                         
 │                                 Intel P4 / older Netburst based Xeon               
 │                                 Intel Atom                                               
 │                                 Intel Core 2                                                   
 │                                 Intel Nehalem                                           
 │                                 Intel Westmere                                               
 │                                 Intel Silvermont                                                 
 │                                 Intel Sandy Bridge                                   
 │                                 Intel Ivy Bridge                                         
 │                                 Intel Haswell                                                 
 │                                 Intel Broadwell                                                     
 │                                 Generic-x86-64                                                 
 │                             <X> Native optimizations autodetected by GCC 
 




^^ This is what I use with my i3 6100 instead of setting CPU type.
Back to top
View user's profile Send private message
Syl20
Guru
Guru


Joined: 04 Aug 2005
Posts: 564
Location: France

PostPosted: Thu Jan 14, 2016 3:12 pm    Post subject: Reply with quote

chithanh wrote:
Nowadays for modern Intel CPUs it is mostly recommended to stay with the performance governor, and delegete power management to the intel_pstate driver instead.

Good to know, thank you.

Unfortunately, my laptop is too old, but some of my desktop machines can use intel_pstate. So, let's go...
Back to top
View user's profile Send private message
wrc1944
Advocate
Advocate


Joined: 15 Aug 2002
Posts: 3271
Location: Gainesville, Florida

PostPosted: Fri Jan 15, 2016 7:14 pm    Post subject: Reply with quote

When you use the experimental gentoo-sources USE flag, among other things at the end of processor section there is a "native" option, which lets GCC detect and utilize the features your hardware (CPU) is capable of.

It's better to use native than select a specific processor option in most cases, as your current gcc compiler version knows best. After all, it is in charge of using your hardware to compile your binaries. 8)

I would also recommend that one use -march=native in your /etc/make.conf file.

I've been doing this for years now with absolutely no problems.
_________________
Main box- AsRock x370 Gaming K4
Ryzen 1700, 3.0GHz, 16GB GSkill Flare DDR4 3200mhz
Samsung SATA 1000GB, Radeon HD R7 350 2GB DDR5
Gentoo ~amd64 plasma, glibc-2.30-r2, gcc-9.2.0 kernel-5.4.1-gentoo USE=experimental
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Kernel & Hardware All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum