HELP!: Netgear FS105 Switch Throughput Question?

[her209]

Hey Anandtechies

I have a question about the aforementioned switch.

I copied a 100MB file from 1 computer to the other (only 2 computers on the LAN) and it took about 60 sec to complete.

Calculating that out, it came out to be about 13Mbps. I checked the lights and it said it was running at 100Mbps. I expected much better performance from the LAN, 75-90Mbps.

I don't know why this could be. I am using Netgear's FA311 NICs in the comp BTW.

Could it be because I have other protocols installed? I have that Windows Login and File Sharing protocol installed along with TCP/IP. But that is it.

What should I do? Any suggestions? Thanks!

her209

 

[wnied]

Try making NETBEUI your default protocol for transferring WITHIN your LAN.

wnied

 

[bex0rs]

Well, according to someone in this thread, you should be able to transfer 120 MB in 5 seconds. Perhaps that person should give all of us advice.

Seriously though, what kind of hardware is in your computers? Some older hard drives cannot sustain 100 Mbps. I've also found that windows networking has a lot of overhead. The best I've been able to do on a switched 100 Mbps lan with decent hardware is ~ 3.5 MB/s.

Although this wouldn't be practical, you might try transferring some files on your lan using FTP. I've gotten > 10 MB/s from the ftp dos client to an NT4 Server running IIS. It made me feel a bit better about my hardware.

~bex0rs

 

[her209]

Here is the Hardware setup of both computers.

1st computer
============
Asus CUSL2
PIII 866EB
Mosel 256MB (2x128MB) PC133 CL2 SDRAM
U160 SCSI Card
IBM U160 HDD
Netgear FA311
Hercules Prophet II
Win2K Pro

2nd computer
============
Iwill VD133
PIII 600EB
Generic 64MB RAM
Maxtor 10GB IDE HDD
8MB AGP VGA
Netgear FA311
Win98

 

[bex0rs]

Your hardware shouldn't be the bottleneck. Have you tested 98 -> 2k and 2k -> 98 transfers? Same?

~bex0rs

 

[CBuxton]

Run netcps to see what kind of speed your are getting. Make sure your cards are forced to 100, full duplex instead of auto detect.

 

[her209]

about 60sec either way.

 

[her209]

where would i find netcps? And how do I force the cards to run at 100Mbps.

 

[CBuxton]

NetCPS

 

[her209]

thanks for the link and replies.

 

[CBuxton]

Oh, and to change your cards to full duplex: Under properties of network neighborhood, then properties of your NIC. Looks for something about link speed and duplex. I use 3Com cards, so I don't know exactly where it is or if the netgear nics have it. Under 2k, properties of my network, properties of lan connection, configure the NIC and look for the same options.

 

[bex0rs]

If the cards are plugged into a switch that can handle it, they should default to 100/Full, as indicated by the LED's on the switch.

~bex0rs

 

[her209]

During the transfer, the 100Mbps lights are on and blink simultaneously which I guess means that data is being transfered.

 

[CBuxton]

What speeds do you get? Copy and paste the output screen.

 

[her209]

I havent tried this yet. The other computer (600EB) is at my parents house and I live 400mi away. Fortunately, I am working on building another 866EB CUSL2 mobo and will run the test with those two machines. Unfortunately, the 2nd computer will not be SCSI RAID based (orignal computer planned for future use of SCSI RAID after HDD + RAID card prices drop to "inexpensive" levels). In the meantime, if you guys are interested, I will have the results posted. Hopefully within a week.

I only have the Mobo + RAM for now. Still need ATX case, CPU, HDD, and maybe inexpensive mouse and KB.

 

[live4spd]

Well not to rain on your parade but I believe 100MBS per second is 100 mega BITS not bytes. Given that 100mega bits divided by 8 (8 bits in a byte) you have a maximum theoritical rate of 12.5Megabytes per second.

So from that standpoint I'd say your are doing pretty good.

 

[her209]

I know that Mbps means Megabits.

I tried it using my roomates older P200 and calculated my results. about 30 Mbps (I think)

The numbers off the top of my head:

104576000 Kb in 28.9 s

I dont understand why it adds the Kb, shouldnt that already be in megabytes.

 

[spidey07]

Transfer rates are almost always limited by physical disk speeds. But first off MS networking is very slow and contains a lot of overhead and poor TCP windowing. Second it is physically impossible to use all of the 100 Mb bandwidth. with the preamble and interframe gaps required by ethernet that brings usable bandwidth down to maybe 92 Mb/sec even less as frame sizes decrease. Then when you subtract actual protocol overhead that lowers you payload bandwidth even more.

So...
1) MS networking is by design and implmentation crappy, not a very good test of network throuput
2) 12.5 MB/sec is impossible
3) ACKs take some amount of time to process, so maybe 11 MB/sec is greatest speed possible.
4) Make sure it is not the physical disk limiting you. FTP servers generally cache recently accessed files so you get that limitation out of the way.
5) Cheap NICs don't have header processing in hardware and can increase CPU and interrupts.
6) 3-5 MB/sec payload transfer rates are good, anything higher is great but really depends on the application and operating system
7) Simply taking your file size and dividing by time is very inaccurate.

Hope this helps. Try changing your duplex to half on each end. Microsoft also has numerous I/O design problems that prevent true full duplex operation and can actually be slower than full duplex. These were fixed in 2000.