Hi,
Here is a quick question about PAE. I am using opensuse 11.4 32bit and the laptop I am using has 2GB memory, but I will upgrade to 8GB soon. So,
Thanks
Sorry, for the 2nd question of my thread above. I make it more clear.
I have one more question: How to install a PAE-enabled kernel? Thanks.
On Fri, 28 Oct 2011 22:26:03 +0000, 1zzzzzz wrote:
> Hi,
>
> Here is a quick question about PAE. I am using opensuse 11.4 32bit and
> the laptop I am using has 2GB memory, but I will upgrade to 8GB soon.
> So,
>
> 1. I know I need a pae-enabled kernel to support 8GB memory if the
> system is 32bit. How to check the kernel is a PAE-enabled one? 2.
> Whether the PAE is enabled automatically when I install the opensuse
> system, no matter how many memory there was?
As I recall, the openSUSE 32-bit kernel includes PAE already, so there
shouldn’t be anything necessary. I don’t think they precompile non-PAE
kernels for 32-bit systems any more.
Is there some reason you’re not going to a 64-bit kernel, though?
(Guessing maybe it’s only a 32-bit system, but you never know)
Jim
–
Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C
On 2011-10-29 00:26, 1zzzzzz wrote:
> 1. I know I need a pae-enabled kernel to support 8GB memory if the
> system is 32bit. How to check the kernel is a PAE-enabled one?
The machine I’m using right now is 64 bit, so I can’t check if this code
works. Try:
zcat /proc/config.gz | grep -i PAE
> 2. Whether the PAE is enabled automatically when I install the opensuse
> system, no matter how many memory there was?
IIRC, yes.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
On 2011-10-29 00:46, 1zzzzzz wrote:
>
> Sorry, for the 2nd question of my thread above. I make it more clear.
>
> 2. I mean the PAE-enabled kernel (opensuse 32bit) is install
> automatically always? Under ubuntu, the PAE-enabled kernel is installed
> automatically only when the computer has >= 3gb memory. If the computer
> has only 2gb memory, then the PAE won’t be installed (there is ways to
> install it later). How about opensuse?
IIRC, it is installed if the cpu supports it, because it also activates
some security features.
> I have one more question: How to install a PAE-enabled kernel? Thanks.
YaST or zypper. Just choose another kernel.
There is one kernel-default and one kernel-pae in the list.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
“uname -a” will tell you which kernel you are using.
The default kernel does not have PAE. The desktop kernel does.
When you get the extra memory, then just install the desktop kernel (if you are not already using that).
Before deciding whether to upgrade to 12.1, take a look at bug 708214.
https://bugzilla.novell.com/show_bug.cgi?id=708214
I don’t know whether that bug will affect your system.
Hi Jim,
I would like to use 64bit opensuse, but I worry some softwares are not compatible with 64bit system.
Can I upgrade to a 64bit kernel from my 32bit opensuse? How? Thanks.
Yes, I use desktop kernel. Does this mean the PAE has been enabled?
Actually, I remember when I use the same system on a computer with 4gb memory, the system shows the memory size is 4096mb. If it is 40966mb, it means the pae is enabled and can also support 8gb memory in later time. Am I right?
On 2011-10-29 14:36, 1zzzzzz wrote:
> I would like to use 64bit opensuse, but I worry some softwares are not
> compatible with 64bit system.
Like what?
> Can I upgrade to a 64bit kernel from my 32bit opensuse? How? Thanks.
It is possible, but not supported. Several people did it. I wrote a
commentary on the procedure on one of the mail lists, I think.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
Yes, you already have PAE on your system.
> I would like to use 64bit opensuse, but I worry some softwares are not
> compatible with 64bit system.
Like what?
;)I don’t know. I just check on the web about 64bit system including windows and linux and some people say that. Then I start to worry. Is it better to use 64bit if there is more than 4gb memory?
> Can I upgrade to a 64bit kernel from my 32bit opensuse? How? Thanks.
It is possible, but not supported. Several people did it. I wrote a
commentary on the procedure on one of the mail lists, I think.
Well. Why not use 64bit directly?:shame:
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
As long as your hardware is 64 bit capable, I would go with that.
I switched to using 64 bit almost a year ago. It has been fine. The only problem that I have run into, is that flash is sometimes a bit flaky (artifacts showing up). That seems to have improved with the most recent flash version.
The only problems that I recall being discussed in the forums, are with skype. When installing 64 bit, there’s an option to also install 32 bit libraries. That apparenly takes care of the skype problems, and allows software compiled for 32 bit to work.
I have a few programs of my own that I compiled years ago, and those are still working even though I did not add those 32 bit libraries. That’s because the basic 32 bit libraries are automatically included with a 64 bit install.
On 2011-10-29 19:26, 1zzzzzz wrote:
>
>> I would like to use 64bit opensuse, but I worry some softwares are not
>> compatible with 64bit system.
>
> Like what?
>
>
> ;)I don’t know. I just check on the web about 64bit system including
> windows and linux and some people say that. Then I start to worry.
Check the date of those posts 
> Is it
> better to use 64bit if there is more than 4gb memory?
The exact answer is complex. Having 64 cpu and code does not mean faster,
but rather that you can move more data at the same time; like a train with
1 or 2 carriages. With some code that was not adapted right you find out
that it uses double the memory imprint.
> Well. Why not use 64bit directly?:shame:
With this machine I installed both 32 and 64 bits, on separate partitions,
just to see what differences I could find. Then, on a third partition I
cloned my old system from my old computer, in 32 bits, and I then upgraded
both version and arch. I still have code running that I compiled about ten
years ago and it works.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
On Sat, 29 Oct 2011 12:36:03 +0000, 1zzzzzz wrote:
> I would like to use 64bit opensuse, but I worry some softwares are not
> compatible with 64bit system.
I would start by checking on the software you want to know. I’ve been
running openSUSE x86_64 since at least 11.2 (might’ve installed it at
11.0), and I haven’t run into any significant compatibility issues. If
you have 32-bit software, there are 32-bit versions of the libraries that
can be installed in order to support that software.
> Can I upgrade to a 64bit kernel from my 32bit opensuse? How? Thanks.
It’s not supported, but can probably be done. If it were me, I’d do a
fresh install with 64-bit, though.
Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C
Hi!
I thought that 8gb of RAM and 32bits OS weren’t compatible, but if you read the wikipedia section about PAE it’s possible to use 8GB and opensuse 32bits with a PAE kernel. But if you check the second paragraph you can read:
“The operating system uses page tables to map this 4-GB address space into the 64 GB of physical memory. The mapping is typically applied differently for each process. In this way, the extra memory is useful even though no single regular application can access it all simultaneously.”
Reading this I’m convinced that a system with 64 bits OS would be faster than a 32bit OS with PAE enabled (and maybe more stable/secure). Also you can install 32bits packages on 64bit OpenSUSE.
I have an AMD 4200+ with 8GB RAM and I’m using 64 bit version of OpenSUSE (11.4). For my configuration everything works OK.
On 2011-10-29 23:26, Jim Henderson wrote:
>> Can I upgrade to a 64bit kernel from my 32bit opensuse? How? Thanks.
> It’s not supported, but can probably be done. If it were me, I’d do a
> fresh install with 64-bit, though.
I did it 
I reported about it
If you make a full backup, there is nothing to lose trying, except time
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
On 2011-10-30 00:16, Ivanjn wrote:
> Reading this I’m convinced that a system with 64 bits OS would be
> faster than a 32bit OS with PAE enabled
No, that affirmation can not be done that easily
You have to try it and do measurements: they are different depending on
code and machine. I did: some code was faster, some slower, most the same.
> (and maybe more stable/secure).
And that one certainly can not be asserted.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
Regarding of this, maybe I should really consider to use 64bit. It worth trying, right? The only bad thing is I need to download the softwares (64bit version) I am using again. Oracle, intel compiler… They are big…
Thanks everyone anyway. Your suggestion is very very useful.
On 2011-10-30 12:46, 1zzzzzz wrote:
> 
Regarding of this, maybe I should really consider to use 64bit. It
> worth trying, right? The only bad thing is I need to download the
> softwares (64bit version) I am using again. Oracle, intel
> compiler… They are big…
Delay that till you need to upgrade to another version.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)