jca@pnet01.cts.com (John C. Archambeau) (05/25/90)
hwajin@daahoud.wrs.com (Hwa Jin Bae) writes: >In article <2755@crash.cts.com> jca@pnet01.cts.com (John C. Archambeau) writes: >> Yes, but that's a quiet ethernet. What I'm referring to is a real noisy >> ethernet that is being used. >> Let me setup a real network of the order of 10+ machines with varying >> performance on the ethernet and I will bet that the performance will be about >> 3 Mbit per second on a good day. > >Not true at all. Even with "a real network" I have here with 30+ various sun >workstations (sparcStations, 3/60's, etc.) and servers (plenty of NFS >traffic), burst throughput performance of around 600 MegBytes/sec can be >sustained without causing meltdowns. This is using severly hacked version >of 4.3 BSD Tahoe TCP/IP running within our realtime OS on a 16Mhz 68020 >VME SBC with an onboard LANCE chip. Try mixing Sun with an Appletalk to ethernet gateway and throw in a few PC's Also, I don't have any idea what you 'hacked' into your realtime OS. If reasonable. Or even better yet, try throwing in a network of Macs with ethernet boards. Also, I don't have any idea what you 'hacked' into your realtime OS. If ethernet performance was a high priority, then you obviously did some fudging to bump up the performance. // JCA /* **--------------------------------------------------------------------------* ** Flames : /dev/null | Small memory model only for ** ARPANET : crash!pnet01!jca@nosc.mil | Unix? Get the (*bleep*) out ** INTERNET: jca@pnet01.cts.com | of here! ** UUCP : {nosc ucsd hplabs!hd-sdd}!crash!pnet01!jca **--------------------------------------------------------------------------* */
hwajin@daahoud.wrs.com (Hwa Jin Bae) (05/27/90)
In article <2803@crash.cts.com> jca@pnet01.cts.com (John C. Archambeau) writes:
Try mixing Sun with an Appletalk to ethernet gateway and throw in a few PC's
Also, I don't have any idea what you 'hacked' into your realtime OS. If
reasonable. Or even better yet, try throwing in a network of Macs with
ethernet boards.
Wrong assumptions. The network I have here does include a PC running
PC NFS and a Gatorbox Appletalk gateway and various other vendors'
machines, in addtion to the ~30 Sun Workstations and a few file
servers. We also have multiple Macs with ethernet boards on the
network. I'm not sure what you're trying to prove here; are you
saying that PC's and Mac's will affect the throughput limit of a
segment of ethernet?
Also, I don't have any idea what you 'hacked' into your realtime OS. If
ethernet performance was a high priority, then you obviously did some fudging
to bump up the performance.
Nope. Wrong again. The modifications were made to the original code
to make it work with our OS. Many minor modifications were made including
rewriting checksum code, rearchitecting the mbuf and clustering mechanisms,
recoding a lot of the redundant socket level code, optimizing various
ethernet drivers to minimize copying (loaning out LANCE ring buffers
to eliminate an extra bcopy), etc. The priority of the network task doesn't
need to be bumped up at all. In fact, the priority of the network task is
quite low, consuming about less than 50 percent of the available CPU time
on a typical MC68020's. The issue you were concerned about was the ethernet
throughput. Whatever the point you're trying to make here (I'm not sure
what your point is), try to perform some real tests and write some real code
to verify your thesis, come up with some real data, analyze the data and
let us know.
hwajin
--
hwajin@daahoud.wrs.comjca@pnet01.cts.com (John C. Archambeau) (05/28/90)
hwajin@daahoud.wrs.com (Hwa Jin Bae) writes: >In article <2803@crash.cts.com> jca@pnet01.cts.com (John C. Archambeau) writes: > Try mixing Sun with an Appletalk to ethernet gateway and throw in a few PC's > Also, I don't have any idea what you 'hacked' into your realtime OS. If > reasonable. Or even better yet, try throwing in a network of Macs with > ethernet boards. > >Wrong assumptions. The network I have here does include a PC running >PC NFS and a Gatorbox Appletalk gateway and various other vendors' >machines, in addtion to the ~30 Sun Workstations and a few file >servers. We also have multiple Macs with ethernet boards on the >network. I'm not sure what you're trying to prove here; are you >saying that PC's and Mac's will affect the throughput limit of a >segment of ethernet? Anything can affect the throughput of an ethernet. If one machine that is part of the network chatter is not up to the speed in processing data (i.e. a slow ethernet card) then it can and often times will affect the through put of the entire network. Overload the Appletalk/ethernet gateway with a large number of Macs telnet'ing into one or more Suns and that will slow things down well since the gateway has to service all of these Macs as well as handle all of the ethernet traffic going into the Appletalk network. The issue is that a lot of things can happen that will make ethernet slower than molasses and it can be in either hardware or software. I've found that from experience that Macs and PC's are the biggest offenders to mucking up ethernet throughput. // JCA /* **--------------------------------------------------------------------------* ** Flames : /dev/null | Small memory model only for ** ARPANET : crash!pnet01!jca@nosc.mil | Unix? Get the (*bleep*) out ** INTERNET: jca@pnet01.cts.com | of here! ** UUCP : {nosc ucsd hplabs!hd-sdd}!crash!pnet01!jca **--------------------------------------------------------------------------* */