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Gigabit Transfers?

G

gunrunnerjohn

Golden Member
<FONT face=Verdana>I have a curious situation with two gigabit cards in a couple of my machines.

I installed the two gigabyte cards in addition to my normal LAN to allow my prime machine and my backup machine to have a faster link for quick transfers. To insure the machines didn't get confused about two paths, I disabled the other link for my tests.

I can browse to the remote machine and drag-n-drop a large file in explorer to the remote machine, and I get what looks like 100mbit speeds, about 8mbyte/sec. OTOH, if I grab a file on the remote machine and drop it in a local directory, I get 25-30mbyte/sec, which is probably limited by the hard disks.

The curious thing is, this happens no matter which machine I'm doing it on, i.e. it's not a problem moving data one way or another over the gigabyte link.

I've tried the test with just TCP/IP, just NETBEUI, and with both, the results are basically identical.

Anyone got any idea what's going on?</FONT>
 
I'm no network expert but it does sound like your hard drives are the bottleneck. What hard drives are you transferring data to/from?
 
I think you're missing my basic point. When I "push" the file from either computer to the other side, the speed is slow. OTOH, when I "pull" the file from either side, the speed is three times as fast, and then it's probably being limited by other factors. My question, since it appears that it's not a directional issue, is why copying from the remote machine is fast, and copying to the remote machine is slow, keeping in mind the behavior is identical on each end. The same disk is able to read or write three times as fast doing the same operation, so I doubt it's a disk issue. 🙂
 
Try using QCheck from NetIq (www.netiq.com).

That will eliminate some of the OS-related questions.

Then the usual stuff: check for current drivers, try the NIC in another slot, etc.

Good Luck

Scott
 
Well, QCheck is interesting, I get 500mhz in one direction and 400mhz in the other direction, using TCP. It drops to around 120-150 using UDP in each direction. I'm not entirely sure what that means! :frown: As a test, I ran it to a XP-Pro machine that is connected through the switch at 100mhz, and it gets 85mhz one way and 95mhz the other way for TCP. It gets 65mhz for the UDP connection each way on the 100mhz link. The results indicate I clearly have a gigabit connection, I'm just not sure why the file transfers are slow when I am writing to the remote computer on either end, but not when I'm reading from it. Very strange... 😕

BTW, thanks for the pointer to QCheck, it's a handy tool, and at least I see that I have a faster connection, now I just have to figure out why I can't always use it. 😀
 
Well, next I'd start playing with the advanced properties for the NIC: stuff like Coalesce buffers (how many packets it'll collect before popping the traffic up the stack)...kill the flow control, stuff like that.

Qcheck is a wunnerful thing. It's a (severly) cut-down version of Chariot; a program we use in the lab to generate traffic streams and analyse the flows.

If you go to www.scottmac.net, I have a "Switch vs. Hub" series of tests using Chariot and a Smartbits (another traffic generator/analyzer).

Good Luck


Scott
 
Your tests are interesting, I'm buying a 5 port gigabit switch to connect a few of the systems into the fast lane, and I'll be tinkering with my backup applications to see how well it all works.

I can't help but think there's something about SMB file handling that is slowing down the writing from a system to a remote system, since it happens in either direction. It certainly is odd...
 
Well, QCheck is interesting, I get 500mhz in one direction and 400mhz in the other direction, using TCP. It drops to around 120-150 using UDP in each direction. I'm not entirely sure what that means! As a test, I ran it to a XP-Pro machine that is connected through the switch at 100mhz, and it gets 85mhz one way and 95mhz the other way for TCP. It gets 65mhz for the UDP connection each way on the 100mhz link. The results indicate I clearly have a gigabit connection, I'm just not sure why the file transfers are slow when I am writing to the remote computer on either end, but not when I'm reading from it. Very strange...

BTW, thanks for the pointer to QCheck, it's a handy tool, and at least I see that I have a faster connection, now I just have to figure out why I can't always use it.
Click to expand...

how did you get the mhz using qcheck ??
 
Another thing to take a look at is that the gigabit cards do not use a standard crossover cable when connecting 2 nics together, as it uses all 8 wires in the ethernet cable. You will want to make sure you are using a regular patch cable for this. This is different from 100mbit in that when connecting 2 nics together you would use a crossover cable.

Dunno if this is the actual problem or not, as this would usually cause it to negotiate a 100mbit connection instead of 1gbit.

-Jeremiah
 
Originally posted by: jagilbertvt
Another thing to take a look at is that the gigabit cards do not use a standard crossover cable when connecting 2 nics together, as it uses all 8 wires in the ethernet cable. You will want to make sure you are using a regular patch cable for this. This is different from 100mbit in that when connecting 2 nics together you would use a crossover cable. Dunno if this is the actual problem or not, as this would usually cause it to negotiate a 100mbit connection instead of 1gbit. -Jeremiah
Click to expand...
My cards specifically say they automagically configure, I'm using a straight CAT5e cable. I also tested the cable with a TDR just to make sure it's really good. 😀
 
Originally posted by: azev
Click to expand...
how did you get the mhz using qcheck ??[/quote]
I open QCheck, select TCP, Throughput, set the Data Size to 1000 (the max), select the From Endpoint and To Endpoint computers and hit run. I believe you need QCheck installed on the other system, because when I ask it to run against a system without it installed, it chokes. 🙂


 
Originally posted by: gunrunnerjohn
Originally posted by: jagilbertvt
Another thing to take a look at is that the gigabit cards do not use a standard crossover cable when connecting 2 nics together, as it uses all 8 wires in the ethernet cable. You will want to make sure you are using a regular patch cable for this. This is different from 100mbit in that when connecting 2 nics together you would use a crossover cable. Dunno if this is the actual problem or not, as this would usually cause it to negotiate a 100mbit connection instead of 1gbit. -Jeremiah
Click to expand...
My cards specifically say they automagically configure, I'm using a straight CAT5e cable. I also tested the cable with a TDR just to make sure it's really good. 😀
Click to expand...

yes so does my trendnet card

auto-crossover
 
Yes, QCheck installs an agent to communicate with the other endpoint (which must also be running the agent).

First they sync up time-wise, then they data dump, then they compare times and calc the throughput (X number of bytes in Y amount of time).

FWIW

Scott
 
Originally posted by: sep
Would this have anything to do with the limitation of the PCI Bus?
Click to expand...

I don't see how. Since, depending on which end I actually invoke the transfer from, I can get a full speed transfer, it seems pretty clear it's some sort of protocol issue, most likely something to do with SMB overhead.
 
Try using something like FTP to transfer the data and see what transfer rates you get. SMB is notoriously flukey when it comes to consistency in transfer speed.
 
I've been meaning to try FTP, and that's a good suggestion. I just got a gigabit 5 port switch, so I'm going to reconfigure to have only one LAN in each machine, it'll be interesting to see how it all plays out. I also have a couple of Intel gigabit cards on order, they should be here soon, then I'll have 4 machines to experiment with. 😀
 
I got the EDIMAX 5 port switch and wired it in. I also received one of my Intel PRO/1000MT gigabit adapters. I put both in. The switch didn't make anything work better, but it also didn't break anything. 😀 I now have a single NIC for all machines again, and the three with gigabit cards are plugged into the gigabit switch. Interesting that the one Intel NIC gets better bandwidth transmitting to the other machine with the AOpen gigabit NIC, but not receiving. It'll be interesting to see what the second Intel does when they're talking to each other. I do feel the Intel NICs will probably be a better product, time will tell...

OTOH, it did nothing for the file transfers, that's still a mystery. I'm convinced it's something about the SMB protocol, so I wonder how this is overcome in servers that obviously have to be able to write faster than I'm seeing. Also FTP didn't do much, I can receive at 35mb/sec, but I was sending at only about 3mb/sec with FTP! That could be the cheap server I installed, or again protocol issues. This isn't as simple as I first envisioned it to be. 😀😀😀
 
isnt gigabit capable of moving file at 125MB/s ?? With this much bandwidth, I think most desktop or server will have problem utilizing all the bandwidth. I moved 500MB - 1GB file quite often between computer. Right now my speed is at the peak of 100Mbps network (10MB/s average). Going up from 10MB to 35MB would be enough reason for me to move to gigabit soon.

gunrunnerjohn, what is the spec on all of your computer ?
 
The computers in question are a P4-2.4g and an AMD 2400+. The problem writing appears to be a protocol issue, since depending on which end I do the transfers from, I can move data either way at around 30mb/sec. Apparently, the SMB overhead for writing and checking is significant. I'm researching to see if there's something that I can do to speed up the writes, since I'm looking for backup speed as a primary purpose. I'm sure it's been solved, I can't imagine that large servers live with 8-9mb/sec total write speed! I have my second Intel gigabit card, so I'll now have 4 computers with gigabit NICs, and one will have Linux running on it, maybe that'll tell a tale...
 
I'm still having issues with my setup.

I've got an existing 100 network, and tried adding gigabit nic's the the 2 main rigs in a nic-to-nic connection.

the problems is that all the traffic from the 2nd box is routing through the giganic to the other box, and then out to my router on it's 100 nic, instead of taking internet traffic trhough the 2nd box's 100 nic directly to the router.

it;s wierd, if I unplugg the 1000 from the 2nd box then it will connect to the network and internet though the 100 nic, but as soon as 1000 is reconnected it's back to routing all traffic through it.

I might have to suck it up and get the EDImax too. so much for a cheap upgrade to gigabit.

we cant be some of the first to try putting this stuff in their homes are we? you'd think someone would know how to run a setup like i've described above. (100 LAN with giganic-to-giganic for direct connection)


Edit: whoohoo! I just made gold!!! :beer:'s on me! 😉
 
I'll take a bass ale. 😀

I had browsing issues until I put the gigabit cards on their own subnet when I had two cards in the machines. However, I think it's a lot simpler just to have one LAN with the switch. I have all my gigabit cards in now, so I need to figure out which one I can install for Linux, the Intel or the AOpen. Probably the Intel will have drivers. I'm curious if the slow file writes will be present with the Linux box as well as Windows. That box also will also boot W98, so I suppose I could try writing to it on the gigabit LAN too and see if that tells me anything. I guess if this stuff were easy, there'd be no work for us! 😀
 
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