Python-list Digest, Vol 31, Issue 94

[Gary Robinson]

> I can't see anything 
>> called a T2100. I have 3 X2100 servers which are opterons.

Right I meant X2100's, sorry.

> Python cannot use psyco on opterons at all - 
> 32 bit mode or otherwise. 

Are you sure? I'm not saying I have reason to believe differently, but 
I just want to be sure.

The Psyco docs say it requires "A 32-bit Pentium or any other Intel 386 
compatible processor. Sorry, no other processor is supported. Psyco 
does not support the 64-bit x86 architecture, unless you have a Python 
compiled in 32-bit compatibility mode". 

Sun's "The Solaris Operating System on x86 Platforms" guide says "The 
AMD64 (64bit x86) 
architecture was done in a way very similar to how Intel had done the 
i80386, and 
processors based on AMD64 (much unlike Itanium/IA64) are, in good old 
x86 tradition, 
fully binary backward compatible. Of course, actually using the new 
64bit operating 
mode requires porting operating system and applications (like using 
32bit on the 
i80386 did require at the time). But even when running a 64bit 
operating system does 
AMD64 provide a sandboxed 32bit environment to run existing 
applications in (again, 
like the i80386 which allowed the same for 16bit programs running on a 
32bit OS). 
Therefore the AMD64 architecture offers much better investment 
protection than IA64 
– which will not run existing 32bit operating systems or applications. 
"

As I read it, this says that when the Opteron is used in "the new 64bit 
operating mode," as it is on the X2100, it is no longer Intel 386 
compatible except in a "sandboxed 32bit environment". Then the question 
would be whether 32-bit python can be run in the sandboxed 32bit 
environment. Since I don't have an X2100 yet and haven't played with it 
or studied the docs yet, I don't know what it entails.

Have you explored that?

> The T2000 has a new 
> cpu for which I have no data about python performance.

The  T2000 has up to 8 relatively slow cores. Python's GIL (and the way 
the app is designed) eliminate the possibility of making use of more 
than one core for now. In the future that may change, but I need an 
immediate solution and re-architecting is not possible right now.

> If you can benchmark your own code on a target machine, on solaris, 
> linux or windows, you can quickly figure out if it's "fast enough". 

The more speed I have, the better output I'll be able to get. This 
application is a case where there is no "fast enough". The more speed, 
the better, within financial constraints.

Gary

-- 

Gary Robinson
VP/Innovation
Emergent Music, LLC
grobinson at goombah.com
207-942-3463
Company: http://www.goombah.com
Blog:    http://www.garyrobinson.net

O 
> Message: 2
> Date: Fri, 07 Apr 2006 02:34:02 GMT
> From: ross lazarus <replytothe at newsgroup.please>
> Subject: Re: 32-bit python on Opteron, Solaris 10?
> To: python-list at python.org
> Message-ID: <uckZf.3380$v9.3221 at trndny01>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> The answers depend entirely on the cpu in my experience. I'm staring 
> at http://www.sun.com/servers/index.jsp and I can't see anything 
> called a T2100. I have 3 X2100 servers which are opterons. Psyco only 
> runs on x86 cpu hardware. Python cannot use psyco on opterons at all - 
> 32 bit mode or otherwise. Pypy may fix this soon. The T2000 has a new 
> cpu for which I have no data about python performance. I am sure it 
> will run, but it may or may not be super fast if that's important to 
> you. On the ultrasparcs I have had an opportunity to fool with, python 
> runs  "fast enough" for computationally intensive tasks (ie it's 
> useable) but relatively slowly compared to the x86 hardware I have 
> access to - particularly if psyco is available. I was once told that 
> python was more at home on CISC than on RISC CPU architecture and 
> being a trusting soul, accept this since it's consistent my own 
> limited experiments.
> 
> If you can benchmark your own code on a target machine, on solaris, 
> linux or windows, you can quickly figure out if it's "fast enough". 
> Exactly what means depends on the throughput you require and a stopwatch.
> 
> Your mileage may vary and there may be sun mavens on the list with 
> more reliable information than mine.
> 
> Gary Robinson wrote:
>>  I'm in the market for a server to run some python code which is 
>>  optimized via psyco.
>>  
>>  Sun T2100 servers come with Solaris 10, which comes with python 
>>  pre-installed. 
>>  
>>  Since those servers use the 64-bit Opteron box, I would assume that the 
>>  Python is a 64-bit version. (Does anyone know whether this is 
>>  true/false?)
>>  
>>  The Psyco documentation says that for psyco to work, Python needs to be 
>>  compiled in "32-bit compatibility mode". I've never compiled Python, or 
>>  tried having multiple versions running on Solaris. I looked at the 
>>  README for the Python source and didn't see anything about "32-bit 
>>  compatibility mode", though I may have missed it. Or is it a matter of 
>>  choosing a 32 bit compiler to compile against? Any info would be 
>>  appreciated.
>>  
>>  Finally, I'm wondering if anyone could give any feedback about 
>>  problems/roadblocks in compiling Python in "32-bit compatibility mode" 
>>  and running it alongside the pre-installed Python that comes with 
>>  Solaris 10.
>>  
>>  Any input or tips would be greatly appreciated.
>>  
>>  Thanks
>>  Gary
>