Article View: comp.os.linux.misc
Article #567Re: Slow Performance froma "Fast Serial Card"?
From: Nils Faerber
Date: Sat, 22 Mar 1997 00:00
Date: Sat, 22 Mar 1997 00:00
38 lines
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2485 bytes
fwtk@niw.cerberus.navy.gov.au wrote: : Can anyone offer me some pointers on this one please? I hope so ... : I am using a Linux box as an Internet gateway for a LAN and some dial-in : lines. The box has two internal 14.4kbps modems and one external 28.8 : kbps modem. Two lines are for dialling in and on to dial out to the : ISP. : If I use one of the 14.4 kbps modems to dial the ISP I get a download : speed of around 1000-1300 bytes/sec. I think this is pretty : reasonable. However, when I try to use the 28.8 kbps modem to dial the : ISP (preferable) the download speed drops to between 100-200 bytes/sec! : ie, about 10 times SLOWER :-( : I think it must be the serial card, but it is a new serial card with : 16550 UARTS. I have tried configuring it at boot time with: This sounds like an interrupt conflict to me. More than two serial ports, and an internal modem is a serial port, are always difficult (there recently was a thread about this somewhere in comp.os.linux.* land). So check your interrupt settings. If you use standard settings you will probably have ttyS0 IRQ 4 ttyS1 IRQ 3 ttyS2 IRQ 4 (!!!) Most PC cards are not designed to share interrupts, but it is possible though. If you can avoid shared interrupt whereever possible. : Thanks, Ian. CU nils -- Nils Faerber ASGARD-BBS asgard.si.sub.de Setzetalstr. 13 eMail: nils@asgard.si.sub.de 57078 Siegen/Germany nils@unix-ag.uni-siegen.de voice +49 271 8909277 http://www.unix-ag.uni-siegen.de/~nils/ data/fax +49 271 8909278 isdn/X75 +49 271 8909279 --
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 1103af,d120540d33c72067 X-Google-Attributes: gid1103af,public X-Google-Thread: f9b51,d120540d33c72067 X-Google-Attributes: gidf9b51,public X-Google-Thread: 10669a,d120540d33c72067 X-Google-Attributes: gid10669a,public X-Google-Thread: 102983,d120540d33c72067 X-Google-Attributes: gid102983,public From: nils@asgard.si.sub.de (Nils Faerber) Subject: Re: Slow Performance froma "Fast Serial Card"? Date: 1997/03/22 Message-ID: <5h0noc$1su@asgard.si.sub.de> X-Deja-AN: 227901481 References: <33308CB0.170C@niw.cerberus.navy.gov.au> Followup-To: comp.os.linux.misc,comp.os.linux.networking,comp.os.linux.setup,aus.computers.linux Organization: First private UseNet for Siegen, Germany Newsgroups: comp.os.linux.misc,comp.os.linux.networking,comp.os.linux.setup,aus.computers.linux