cmaeda@EXXON-VALDEZ.FT.CS.CMU.EDU (Christopher Maeda) (02/02/91)
I'm having performance problems... I have a thin ethernet with two hosts, a NeXT (25mhz 68030, 4.3 BSD) and a pc (4.77mhz 8088, ka9q Version="113090", 3c501 with packet driver v 7.2 from Clarkson). When I try to ftp files between the two, I get throughput on the order of 12kpbs for small files and large files end up timing out. Is this the kind of performance that I should expect given the crappy hardware on the pc or is something wrong somewhere? If the latter is the case, can someone give me pointers on tuning for better performance? TNX Chris
nelson@sun.soe.clarkson.edu (Russ Nelson) (02/03/91)
In article <9102012059.aa22267@louie.udel.edu> cmaeda@EXXON-VALDEZ.FT.CS.CMU.EDU (Christopher Maeda) writes:
I have a thin ethernet with two hosts, a NeXT (25mhz 68030, 4.3 BSD)
and a pc (4.77mhz 8088, ka9q Version="113090", 3c501 with packet
driver v 7.2 from Clarkson). When I try to ftp files between the two,
I get throughput on the order of 12kpbs for small files and large
files end up timing out. Is this the kind of performance that I
should expect given the crappy hardware on the pc or is something
wrong somewhere?
The 3c501 cannot handle back-to-back packets. I'm sure that your NeXT
will send back-to-back packets if your pc is advertising the appropriate
TCP window. The solution? Make the tcp window the same size as the
tcp mss.
--
--russ <nelson@clutx.clarkson.edu> Humble Quaker, and damned proud of it.
It's better to get mugged than to live a life of fear -- Freeman Dyson
I joined the League for Programming Freedom, and I hope you'll join too.karn@epic..bellcore.com (Phil R. Karn) (02/03/91)
In article <NELSON.91Feb2112045@sun.clarkson.edu> nelson@clutx.clarkson.edu (aka NELSON@CLUTX.BITNET) writes: >The 3c501 cannot handle back-to-back packets. I'm sure that your NeXT >will send back-to-back packets if your pc is advertising the appropriate >TCP window. The solution? Make the tcp window the same size as the >tcp mss. Even better, try replacing your 3C501 with a more modern card. Almost *any* other Ethernet adaptor will work much better since they can handle the back to back packets that make up a transfer into a large window. My experience is that binary file transfers are usually limited by the disk transfer rate (and MS-DOS overhead) on most PCs. Ascii transfers are slower.. At home I use a no-name Chinese clone of a NE-2000 that cost me about $130 last summer. It works just fine. Phil