25 Mar
2013
25 Mar
'13
8:06 p.m.
The laptop I'm considering (Zareason Verix 530) as replacement for my
current one has a dual-core Intel i3 processor with hyperthreading.
Zareason says there's no way to turn off HT in BIOS.
I think folk on the list have said that HT causes problems with RT. So
how can I disable hyperthreading?
Thanks.
--
David
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://clanjones.org/david/
http://dancing-treefrog.deviantart.com/
25 Mar
25 Mar
8:25 p.m.
Hi David!
Not, that I'm an expert, but I can't see, why HyperThreading should cause
with RT.
Still, if there is a possibility to deo this from inside Linux, you'll have
to look into the sys filessystem.
/sys/devices/system/cpu/
is a likely point to start looking.
Asfar as I am aware, hyperthreading has been used for years and is quite an
essential part of cpu design, I shouldn't even say "modern" in this context,
for I heard this mentioned in one of my computer science lectures back in the
early 2000s and that was one of the profs actually involved with the practical
side.
Take this with a pinch of salt.
Warm regards
Julien
----------------------------------------
http://juliencoder.de/nama/music.html
9:23 p.m.
Hi David,
I have seen hyperthreading cause issues with audio applications (CPU
usage spikes). My understanding is that this is because the CPU tells
the operating system that it has twice the number of cores that it
actually has. A hyperthreading CPU can do a limited amount of work in
parallel, but for audio where you're doing the same thing over and
over on multiple threads it can cause issues when you need to turn
around a result in a reliable and short number of milliseconds.
However, I am not a hardware engineer so it's possible that my
explanation isn't as accurate as it could be, so take it with some
grain of salt :).
It can typically be disabled as an option in the BIOS.
-Louis
On Mon, Mar 25, 2013 at 12:26 PM, Julien Claassen <julien(a)mail.upb.de> wrote:
Hi David!
Not, that I'm an expert, but I can't see, why HyperThreading should cause
with RT.
Still, if there is a possibility to deo this from inside Linux, you'll
have to look into the sys filessystem.
/sys/devices/system/cpu/
is a likely point to start looking.
Asfar as I am aware, hyperthreading has been used for years and is quite
an essential part of cpu design, I shouldn't even say "modern" in this
context, for I heard this mentioned in one of my computer science lectures
back in the early 2000s and that was one of the profs actually involved with
the practical side.
Take this with a pinch of salt.
Warm regards
Julien
----------------------------------------
http://juliencoder.de/nama/music.html
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26 Mar
26 Mar
10:44 a.m.
Thanks. Unfortunately, the Verix 530 I'm looking at doesn't offer an
option to disable HT in BIOS.
On 03/25/2013 10:23 AM, Louis Gorenfeld wrote:
Hi David,
I have seen hyperthreading cause issues with audio applications (CPU
usage spikes). My understanding is that this is because the CPU tells
the operating system that it has twice the number of cores that it
actually has. A hyperthreading CPU can do a limited amount of work in
parallel, but for audio where you're doing the same thing over and
over on multiple threads it can cause issues when you need to turn
around a result in a reliable and short number of milliseconds.
However, I am not a hardware engineer so it's possible that my
explanation isn't as accurate as it could be, so take it with some
grain of salt :).
It can typically be disabled as an option in the BIOS.
-Louis
On Mon, Mar 25, 2013 at 12:26 PM, Julien Claassen <julien(a)mail.upb.de> wrote:
> Hi David!
> Not, that I'm an expert, but I can't see, why HyperThreading should cause
> with RT.
> Still, if there is a possibility to deo this from inside Linux, you'll
> have to look into the sys filessystem.
> /sys/devices/system/cpu/
> is a likely point to start looking.
> Asfar as I am aware, hyperthreading has been used for years and is quite
> an essential part of cpu design, I shouldn't even say "modern" in this
> context, for I heard this mentioned in one of my computer science lectures
> back in the early 2000s and that was one of the profs actually involved with
> the practical side.
> Take this with a pinch of salt.
> Warm regards
> Julien
>
> ----------------------------------------
> http://juliencoder.de/nama/music.html
--
David
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://clanjones.org/david/
http://dancing-treefrog.deviantart.com/
25 Mar
25 Mar
9:39 p.m.
On 03/25/2013 08:06 PM, david wrote:
The laptop I'm considering (Zareason Verix 530) as
replacement for my
current one has a dual-core Intel i3 processor with hyperthreading.
Zareason says there's no way to turn off HT in BIOS.
I think folk on the list have said that HT causes problems with RT. So
how can I disable hyperthreading?
I can do like this in my Kubuntu system which have 8 kernels:
sudo echo 0 > /sys/devices/system/node/node0/cpu0/online
sudo echo 0 > /sys/devices/system/node/node0/cpu2/online
.
.
sudo echo 0 > /sys/devices/system/node/node0/cpu7/online
To my surprise, they are enabled (value 1) in my system, I thought that
hyperthreading was disabled in my BIOS. That might explain why I have
xruns earlier than expected on my system. I'm glad you asked about this
in the forum. :-)
Jostein
11:19 p.m.
On 03/25/2013 09:39 PM, Jostein Chr. Andersen wrote:
I can do like this in my Kubuntu system which have 8 kernels:
sudo echo 0 > /sys/devices/system/node/node0/cpu0/online
sudo echo 0 > /sys/devices/system/node/node0/cpu2/online
.
.
sudo echo 0 > /sys/devices/system/node/node0/cpu7/online
Correction: You might forget about it. I have an AMD CPU and this don't
apply to this processors if I understand it right. Sorry.
Jostein
28 Mar
28 Mar
6:09 p.m.
On 03/25/2013 10:39 AM, Jostein Chr. Andersen wrote:
On 03/25/2013 08:06 PM, david wrote:
You're welcome. I'm glad I found an answer! I'll have to check by
desktop machine (AMD Phenom IIx4) now, might explain things there, too.
--
David
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://clanjones.org/david/
http://dancing-treefrog.deviantart.com/
The laptop I'm considering (Zareason Verix
530) as replacement for my
current one has a dual-core Intel i3 processor with hyperthreading.
Zareason says there's no way to turn off HT in BIOS.
I think folk on the list have said that HT causes problems with RT. So
how can I disable hyperthreading?
I can do like this in my Kubuntu system which have 8 kernels:
sudo echo 0 > /sys/devices/system/node/node0/cpu0/online
sudo echo 0 > /sys/devices/system/node/node0/cpu2/online
.
.
sudo echo 0 > /sys/devices/system/node/node0/cpu7/online
To my surprise, they are enabled (value 1) in my system, I thought that
hyperthreading was disabled in my BIOS. That might explain why I have
xruns earlier than expected on my system. I'm glad you asked about this
in the forum. :-) 
25 Mar
25 Mar
10:05 p.m.
On 03/25/2013 08:06 PM, david wrote:
The laptop I'm considering (Zareason Verix 530) as
replacement for my
current one has a dual-core Intel i3 processor with hyperthreading.
Zareason says there's no way to turn off HT in BIOS.
I think folk on the list have said that HT causes problems with RT. So
how can I disable hyperthreading?
Thanks.
http://jack-audio.10948.n7.nabble.com/Jack-Devel-AMD-Bulldozer-CPUs-shared-…
Regards,
Jeremy
11:25 p.m.
On Mon, 25 Mar 2013 22:05:42 +0100, Jeremy Jongepier wrote:
On 03/25/2013 08:06 PM, david wrote:
Strange thread, but "IMO, the Bulldozer core is AMD's answer to the
Pentium 4."
made me chuckle.
I just don't get the fear of UEFI?
--
John.
The laptop I'm considering (Zareason Verix
530) as replacement for my
current one has a dual-core Intel i3 processor with hyperthreading.
Zareason says there's no way to turn off HT in BIOS.
I think folk on the list have said that HT causes problems with RT. So
how can I disable hyperthreading?
Thanks.
http://jack-audio.10948.n7.nabble.com/Jack-Devel-AMD-Bulldozer-CPUs-shared-…
26 Mar
26 Mar
6:32 a.m.
On 26/03/13 06:25, John Murphy wrote:
On Mon, 25 Mar 2013 22:05:42 +0100, Jeremy Jongepier
wrote:
I just don't get the fear of UEFI?
Because UEFI is designed to prevent hardware being booted unless it is into an
unmodified and signed OS version, and this hardware lock can be set up so it
cannot be turned off, and for some devices (eg non intel tablets) microsoft (for
example) will only certify them if they are locked this way to run only
microsoft signed software. So most windows tablets can never be loaded with
anything not signed by microsoft ... that is they can now be "trusted" not to
have anything else running on them ... for example something modified by the
person who thinks they own the device, perhaps linux, perhaps a patched windows,
perhaps some system not so compliant with the demands of media distribution
companies as the standard windows is.
Fortunately this would be a major pain to windows users on a PC, since older
versions wouldn't boot ... but given windows on a tablet is new, and a much more
locked down device than a PC, and perhaps also that the hardware manufacturers
of tablets are more willing to go down this path than PC manufacturers, then
this is applied to tablets (where they can probably get away with it) but not
PCs. For intel devices microsoft does not require UEFI to be set so it can't be
turned off, for non-intel tablets it does. So Linux is locked out of any such
devices.
Not good if you like to run linux, so don't buy windows tablets of course ...
and be very cautious of UEFI on any device since it means you no longer have
control of hardware you thought you had bought and now own. What you do with it
is limited by what the UEFI settings let you do, and in some cases you are
unable to change these settings.
Simon
10:09 a.m.
On 03/25/2013 07:31 PM, Simon Wise wrote:
On 26/03/13 06:25, John Murphy wrote:
Zareason sells their systems with Linux installed. Your choice of Linux.
So no concerns about UEFI.
I've also been told that if you buy an UEFI system with Windows 8
installed, then turn of secure boot, you have to reinstall Windows 8.
--
David
gnome(a)hawaii.rr.com
authenticity, honesty, community
http://clanjones.org/david/
http://dancing-treefrog.deviantart.com/
On Mon, 25 Mar 2013 22:05:42 +0100, Jeremy
Jongepier wrote:
I just don't get the fear of UEFI?
Because UEFI is designed to prevent hardware being booted unless it is
into an unmodified and signed OS version, and this hardware lock can be
set up so it cannot be turned off, and for some devices (eg non intel
tablets) microsoft (for example) will only certify them if they are
locked this way to run only microsoft signed software. So most windows
tablets can never be loaded with anything not signed by microsoft ...
that is they can now be "trusted" not to have anything else running on
them ... for example something modified by the person who thinks they
own the device, perhaps linux, perhaps a patched windows, perhaps some
system not so compliant with the demands of media distribution companies
as the standard windows is.
Fortunately this would be a major pain to windows users on a PC, since
older versions wouldn't boot ... but given windows on a tablet is new,
and a much more locked down device than a PC, and perhaps also that the
hardware manufacturers of tablets are more willing to go down this path
than PC manufacturers, then this is applied to tablets (where they can
probably get away with it) but not PCs. For intel devices microsoft does
not require UEFI to be set so it can't be turned off, for non-intel
tablets it does. So Linux is locked out of any such devices.
Not good if you like to run linux, so don't buy windows tablets of
course ... and be very cautious of UEFI on any device since it means you
no longer have control of hardware you thought you had bought and now
own. What you do with it is limited by what the UEFI settings let you
do, and in some cases you are unable to change these settings.
4193
days inactive
4196
days old
linux-audio-user@lists.linuxaudio.org
10 comments
7 participants
participants (7)
-
david -
Jeremy Jongepier -
John Murphy -
Jostein Chr. Andersen -
Julien Claassen -
Louis Gorenfeld -
Simon Wise