Cat 5 crossover cable super slow!

Semple

Semple

Semple

Soldato
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5 Mar 2010
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I'm using a cat5 crossover cable to transfer files between two computers. Whilst the ports both support 1gbps. I'm only seeing transfer rates of around 3/4 - 1mbps.

Surely I should be seeing speeds a lot faster than this. Anything i'm doing wrong?
 
Believe it or not the NIC can have a lot of influence on these things. I imagine that's probably your issue. Although that does seem slow, what and how are you transferring files?
 
1) Connected two computers via crossover cable
2) Set the IP addresses for the two NIC's to different than the network, also different subnet.
3) Shared the folder via windows (Right click folder -> Share with -> Homegroup (R/W))
4) On the 2nd computer through a windows browser gone to //computer1/folder
5) Using teracopy to transfer the files from the network share directly onto the hdd of pc2
 
Have you tried it with a standard network cable? It shouldn't make any difference, but as Gigabit connections don't need crossover cables it's worth a try.
 
bremen1874 said:
Have you tried it with a standard network cable? It shouldn't make any difference, but as Gigabit connections don't need crossover cables it's worth a try.
Click to expand...

Thought a crossover cable was crucial for transferring data. Not just for connecting two machines together?
 
Still no luck :(

I've now tried accessing the share via it's IP rather than hostname. Made no change.

I've used an ordinary cat5 cable. Data does transfer between the two machines but same transfer rate.

I've also tried enabling flow control on both NICs but that's not made any different either.

Any more ideas?
 
My advice would be check the status of the NIC in windows, make sure both NICs are correctly operating at 1Gb/s. If they are Gigabit NICs but showing as 10 or 100Mb/s it could mean a bad cable causing it to fall back to a slower speed (10 and 100 Mb/s only require 2 pairs of wires for example, but gigabit requires all 4 pairs, so if 1 wire was damaged Gigabit would not be possible but slower speeds may be).

Also it is worth trying to the file transfer when both machines are idle, as I know from my network that I can transfer several GB files to another machine on my gigabit network at 40 to 50 MB/s when the destination is idle, but if the machine is running a game or watching a video that speed can drop to 6 to 14 MB/s.

And regarding crossover cable, it is true that like devices require a crossover cable for communication, but one of the requirements for Gigabit Ethernet is Auto-MDIX, which regardless of the cable being a straight-through or crossover cable the NIC can internally flip the pairs if needed.
 
Kind of sounds like you have the computers connected to more than one network (i.e. the 'standard' network in your house and also the network formed by the single cable running between the two machines). If that's the case, try disconnecting them both from the standard network.

Also, are you transferring lots of really small files? These will slow down the speed of transfer massively.

Aside from that, Dist's advice is very good too.
 
Semple said:
1) Connected two computers via crossover cable
2) Set the IP addresses for the two NIC's to different than the network, also different subnet.
Click to expand...

Try entering the IP adddresses and computer names in the hosts file on each machine? That is the advice I was given here a while ago. In case they are being transferred across the "normal" network if one exists as well, as FrenchTart suggests
 
What OS is this - is this Vista to XP and vice versa? I seem to recall some kind of thing with vista or win 7 to XP as they use different stacks or something. I bet if you FTP accross (rather using windows file sharing/cifs) you'll get proper speeds.
 
bremen1874 said:
Have you tried newer (or older) NIC drivers?

Have you tried disabling AV and firewall?
Click to expand...

The server doesn't have AV and the firewall has been turned off. I'll check some settings with the firewall and AV on the host machine.

Also I've not looked into updating the drivers actually. Although in my time of updating drivers I find NICs don't seem to get updated much.

Dist said:
My advice would be check the status of the NIC in windows, make sure both NICs are correctly operating at 1Gb/s. If they are Gigabit NICs but showing as 10 or 100Mb/s it could mean a bad cable causing it to fall back to a slower speed (10 and 100 Mb/s only require 2 pairs of wires for example, but gigabit requires all 4 pairs, so if 1 wire was damaged Gigabit would not be possible but slower speeds may be).

Also it is worth trying to the file transfer when both machines are idle, as I know from my network that I can transfer several GB files to another machine on my gigabit network at 40 to 50 MB/s when the destination is idle, but if the machine is running a game or watching a video that speed can drop to 6 to 14 MB/s.

And regarding crossover cable, it is true that like devices require a crossover cable for communication, but one of the requirements for Gigabit Ethernet is Auto-MDIX, which regardless of the cable being a straight-through or crossover cable the NIC can internally flip the pairs if needed.
Click to expand...

I did look into configuring the speeds of both NICs. Have had them set at auto-negotiate and forced at 1gbps. Unfortunately no difference.

The server machine is idle, only running the OS and teracopy for transferring files from the cifs share.

And yeah I wasn't aware the NIC could flip the pairs. But either way I have tried the transfer with a crossover cable and a straight-through cat5 cable. Which also didn't make any difference :(.

FrenchTart said:
Kind of sounds like you have the computers connected to more than one network (i.e. the 'standard' network in your house and also the network formed by the single cable running between the two machines). If that's the case, try disconnecting them both from the standard network.

Also, are you transferring lots of really small files? These will slow down the speed of transfer massively.

Aside from that, Dist's advice is very good too.
Click to expand...

That was originally my thought as both of them have been set up with wireless adaptors to connect to the home network. Removing the adaptor on the server only increased it from 1mb to 2mb. Also I can see the status of the physical ports sending/receiving data.

Also no, files have been ranging from a few mb up to a few gb.

Tuvoc said:
Try entering the IP adddresses and computer names in the hosts file on each machine? That is the advice I was given here a while ago. In case they are being transferred across the "normal" network if one exists as well, as FrenchTart suggests
Click to expand...

Yea I did try IP addresses rather than hostname's but didn't seem to make any difference.

whitecrook said:
What OS is this - is this Vista to XP and vice versa? I seem to recall some kind of thing with vista or win 7 to XP as they use different stacks or something. I bet if you FTP accross (rather using windows file sharing/cifs) you'll get proper speeds.
Click to expand...

Windows 7 to Windows Server 2008. I will give FTP a shot if I can't boost these speeds.
 
Okay it seems my problem is to do with my RAID setup.

I have 6 x 1tb disks in RAID 5 set-up and 2 x1tb disks in RAID 1 set-up.

I first noticed the problem when connecting a USB drive and copying from there. After seeing 2.5mbps transfer rates I knew the networking wasn't the problem. So on my 1tb disks I copied from the cifs share and was getting around 50mbps (now THATS more like it :D)

So I guess my next question. What problems could I be seeing with this RAID set-up to cause such a bottleneck.


EDIT: Also to add, i'm not just noticing the problem with external devices. Copying from the RAID 1 drives to the RAID 5 drivers I can still only achieve about 3mbps.
 
bremen1874 said:
What RAID controller are they connected to?

Is the array actually heathy? A dropped drive or a rebuild in progress would make a massive difference.
Click to expand...

I did notice when booting it says "rebuild", But it shows all the disks as active.

RC is the onboard intel controller


Are there any tools that run in the OS that can check the health of individual drives within an array? I tried Crystal Disk info but it doesn't seem to work with an array :(
 
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