Subject: Re: netatalk races
To: Lee Larson <llarson@louisville.edu>
From: Capt. Avram Dorfman <dorfman@pentagon.mil>
List: port-mac68k
Date: 01/12/1998 17:35:37
I would have to disagree w/ you on the reason for A/UX ftp being faster
than MacOS or netatalk: ftp uses TCP/IP. Apple file sharing uses AFP/DDP
(Apletalk).
First of all, IP allows up to 1.5kb datagrams, DDP allows a max of 600
bytes. This give you about 1/3 as much overhead w/ TCP. Second, TCP has a
much better windowing mechanism. It can have many more outstanding
packets (those which have not been acknowledged). AFP *must* send an ack
packet at at for at least every 8 packets.
Combine these together, and what you get is that Appletalk spends a lot
of time sending headers, and sitting around waiting for acks, compared to
TCP.
In order to have a fair test when compared w/ A/UX, you'd really have to
be FTPing to the netbsd boxes, and install Peter Lewis' NetPresenz or
FTPd on your MacOS.
-Capt Avram Dorfman
Chief, Network Operations
email: dorfman@pentagon.mil
(last resort email: avram@pobox.com)
:%s/\(do|-<\)/\1\1/g
:1,$d
On Wed, 7 Jan 1998, Lee Larson wrote:
> Here are a few comparisons between NetBSD+netatalk and Mac OS file
> sharing. The setup is 10Base-T ethernet on a network with two ci's, and
> fx and a PowerBase 240. I ran Helios LANtest on the PowerBase. Here are
> the configurations of the machines:
>
> (1) One ci is running NetBSD 1.3 and netatalk 1.4b2. Its name is Sauron.
>
> (2) The other ci is running Mac OS 7.6.1 and Open Transport 1.1.2.
>
> (3) The fx is running Mac OS 7.6.1 and Open Transport 1.1.2.
>
> (4) The PowerBase has Mac OS 8 and Open Transport 1.2.
>
> The results:
>
> Action Sauron ci fx
>
> create 100 files @20K (sec) 58.56 35.93 25.46
> open/close 100 files (sec) 7.74 7.07 5.53
> remove 100 files (sec) 13.09 8.51 6.51
> write 3 MB to a file (KB/sec) 49.44 86.03 130.72
> read 3 MB from a file (KB/sec) 108.28 67.67 117.72
> lock/unlock 4000 times (sec) 99.84 109.05 101.08
> read directory 320 files (sec) 4.66 1.29 0.93
>
> This was done on a 10base-T ethernet with only those machines and a
> printer installed. All results are from averaging 10 runs of each test.
> Both the ci's a pretty much the same hardware. I get almost three times
> the speed from Sauron, if I transfer files by ftp from the PowerBase.
>
> As a side note, running A/UX 3.02 on the fx gives over 300 KB/sec via ftp
> between the PowerBase and the fx. I think this is because A/UX knows how
> to take advantage of DMA on the fx, while Mac OS does not.
>
> Lee Larson http://www.louisville.edu/~lmlars01/ (502)852-6826
> Mathematics Department, University of Louisville, Louisville, KY 40292 USA
>