Re: real kernel bloat
Alex Krimkevich (alex@magneton-ra.swmed.edu)
Thu, 27 Jun 1996 10:15:08 GMT
Malcolm Beattie writes:
> >See above. In addition to that, let me add, that user's perspective
> >of what OS is, is quite different from yours, Linux major contributor.
> >As a user, I don't run kernel tcp/ip benchmarks, I run ftp instead.
> >And what I see is that ftping from Solaris 2.4/Sparc2 to AlphaStation
> >on a different subnet delivers 660KB/s on average. The Linux box,
> >which hardware wise should beat the crap out of an ancient Sparc
> >delivers 250 KB/s.
>
> What kernel version and what ethernet card? You should be seeing at
> least 750-850Kb/sec with an equivalent ethernet card/CPU. I run our
> web server with Linux 2.0 and NFS export the filestore to the
> general purpose 2100 Alphaservers from which our users get at their
> web pages. The web server is a Pentium 133MHz running Linux 2.0 with
> a 3com 3c590 PCI ethernet card and I get 500Kb/sec with NFS. That's
> not even with the latest 3c590 driver which should be even faster,
> I believe. If you're getting 250Kb/sec with ftp then you're either
> not runing Linux 2.0 or you've got a much worse ethernet card which
> you shouldn't be comparing with the (presumably) reasonable one that
> Sun installed in their box.
I run 2.0 kernel, networking is built in, not a module. My ethernet
card is 3c509. Not as good as yours, but manages 800 Kb/s on the
same machine ftping from the same host under NT. As a matter of fact,
I remember seeing transfer rates similar to that under 1.3.20.
So, probably, it's not a hardware deficiencies.
It looks to me, that Linux' manners on congested networks are less
than perfect. Consider it a hunch. The only data I have to back
this assumption is that when 'ping' indicates packet dropout of
about 20% or more, Linux' tcp/ip performance becomes untolerable.
Even old (at least 10 years old) Sun4/SunOS 4.1.1 box seems
to outperform Linux under these circumstances.
Alex Krimkevich