Date: Wed, 10 Mar 1999 18:52:31 -0500 From: "David W. Alderman" <dave@mmrd.com> To: freebsd-hardware@FreeBSD.org Subject: Re: PCI WinModem Message-ID: <36E705BF.17CA68EA@mmrd.com> References: <199903102311.SAA20812@lonesome.ma.ikos.com>
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I really hate to chime in on this, but... There are different kinds of winmodems. Some use the CPU to handle user level commands (AT commands). Others also use the CPU to handle data compression and decompression. The cheapest also use the CPU for codec functions (along with hardware, of course). The command-only winmodems have a minimal impact on system performance since the command functions are not needed while a connection is actually in place. The two other types place a progressively greater load on the CPU all of the time they are in use. Unfortunately, it is difficult to tell which is which. There is also line conditioning and interface hardware that is often cheapened or omitted from winmodems. If your results are good - fine. Others have not been so lucky. One thing I have noticed about Windows 9x is that it cannot handle multiple ftp transfers if the serial baud rate is set higher than 57,600. Try ftp'ing over four files at once with your serial baud set to 115,200 and see what happens. I don't think FreeBSD (or Linux, for that matter) will have a problem with this. If 3Com or Rockwell or Lucent would make their Winmodem code available for use by the open software community, I suspect someone would write a driver for it. As far as I know, that has not happened. Attributing the economy of winmodems to Microsoft is misguided - Windows is the benificiary of cheap modems because of market share. It is certainly not easier to write drivers for Windows. If you like Winmodems, then thank the companies that bring them to you, or better still, the chip and firmware makers. Richard Cownie wrote: > >How do you define good performance? They slow down your cpu doing > > I measured a download rate of 5.5KB/sec, which is a) 85% of the > theoretical peak, and b) about 20% faster than the badnwidth I get > using FreeBSD and a real modem (and a faster cpu). That's > good performance. > > And I didn't notice any significant slowdown while this was running - > if you really want to argue that WinModem's are evil because they > slow down the system you'd better come up with some numbers to > make it stick. > > Microsoft may or may not be bad, but the fact that they've built > a system which allows me to do 5.5KB/sec transfers with a $20 > modem doesn't seem bad to me. You can still buy a "real" modem > for more money if that's what you want, but if you want to > criticize WinModem's then please come up with some substantive > and quantitative argument. > -- Dave Alderman - Democracy should not be capital intensive. Business: dave@persprog.com is changing to dave@mmrd.com Personal: dwa@atlantic.net -or- dwa@netcommander.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
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