Processor Scalability and Linux

john wendel jwendel10 at
Sun Aug 8 17:01:46 UTC 2010

On 08/08/2010 08:12 AM, Joshua C. wrote:
> Hi,
> I’ve been planning on buying a new machine but I’m not that sure what to take.
> We’ve been seeing test and reviews on the internet between amd and
> linux. I can say that when it comes to pure (single) core apps then
> intel might have the lead. When it comes to scalability then amd is on
> the move. You can check some recent reviews between i5–750/760 and
> 1055t/1090t for this. I DO NOT want to start a one–is–better
> discussion here.
> We know that in the windows world most of the apps aren’t optimized
> for multicore processers. I think the windows OS isn’t optimized
> either. Therefore the discussion goes down to “what are you going to
> do with it? If you work with video (photoshop) then amd, else  – maybe
> intel”.
> However I want to ask how well linux scales on multicore processors. I
> know that maybe more that 90% of all internet servers are running with
> some version of linux. But this doesn’t mean that linux scales better
> than windows, because maybe the costs are at play here – Free (as in
> Freedom) vs. $$. Most of the linux apps are compiled with GCC 4.xx.
> Therefore it goes down to how well GCC is optimized for a multicore
> processor.
> My machine also must satisfy some other criteria:
> 1.) future–proof (that’s why an amd 6–core ???)
> 2.) must be environmental friendly (less watts) (that’s why an intel)
> 3.) good linux support (I’ll put intel here because I think their
> overall support is better than amd. Remember the SB850 and how fast
> amd responded? What about ati?)
> Therefore I’m asking if a 6–core amd makes more sense in linux than in
> windows? How well does linux scales?
> --Joshua
> PS. I’ll be happy to see some links with some results to support your answers.

Fastest computer in the world is built from AMD processors and runs 
Linux on 250,000 processors. I think you'll be OK. I seem to recall that 
Cray (or the old SGI) did the work to let Linux scale to ~1000000 cores 
(it may be used some day).

As for which OS makes more sense, you don't use an OS, you use an 
application program. If Linux doesn't run your application and Windows 
does, I think you know the answer.

Remember that whatever you buy will be obsolete in a year (or two). 
Unless you have an unlimited budget, you can't stay on the leading edge. 
That 6-core AMD you're lusting for today will be replaced by the 16-core 
Bulldozer (or whatever) next year. And of course, the bastards will 
change the CPU socket so you can't upgrade without buying a new 
motherboard (and probably new DDR-x memory).




More information about the users mailing list