Null modem?

[dteowner]

I was trying to directly link my work laptop and my PC. I thought I could connect their network cards with an ethernet cable and be good to go, but that isn't working. I think they're both trying to establish themselves as master of the connection and just bumping heads. I've heard of null modems in the past, but perhaps I'm completely misapplying my lousy memory. I'll just use my thumb drive for now, but it would be nice to know something for the future. Thanks.

 

[Moriendor]

You need to use a crossover Ethernet network cable if you want to connect one device directly to the other. A regular LAN cable will not work.

 

[Lucky Day]

what he said

or get yourself a cheap hub/switch/router and use two cables. Don't bother with connecting serially or with parallel cables as you will discover how agonizingly slow they've become.

 

[dteowner]

Thanks, gents. The transfer via thumb drive is done, but it was annoying enough that I'll probably try your recs if I have to do it again.

 

[Prime Junta]

what he said

or get yourself a cheap hub/switch/router and use two cables. Don't bother with connecting serially or with parallel cables as you will discover how agonizingly slow they've become.

Seconded. However, if you're connecting over vanilla 10/100 Ethernet, it's still pretty slow compared to just shunting the stuff with a USB drive and Sneakernet; gigabit Ethernet is nice and fast though.

 

[GothicGothicness]

100 mbit ethernet is fast enough, I'd say. Unless you're very impatient.

 

[txa1265]

100 mbit ethernet is fast enough, I'd say. Unless you're very impatient.

Dammit will you type faster!!!



When doing this stuff I use USB2 external drives ... and Firewire for the Macs ... and gawd USB2 is slow by comparison ...

 

[Prime Junta]

Dammit will you type faster!!!



When doing this stuff I use USB2 external drives ... and Firewire for the Macs ... and gawd USB2 is slow by comparison ...

Sounds like there's something wrong with your USB2. It should be nearly five times faster than 100 Mbps Ethernet. If you're transferring a diskful of stuff, that makes a quite a significant difference, even considering that you only need to pipe it through once via Ethernet.

 

[Moriendor]

Sounds like there's something wrong with your USB2. It should be nearly five times faster than 100 Mbps Ethernet.

In theory, yes, but in practice this is by far not true. I just did a quick Google search and found this page where they have a performance comparison of Firewire vs USB 2.0. Even though USB 2.0 has the faster interface, it is up to 70%(!) slower than Firewire. Or check out this chart at Tom's Hardware. USB 2.0 is not even getting close to its theoretical specs and it's in some cases (with the slower 2.5" notebook HDs) only a little bit faster than the 100MBit device that they have listed.
The 480MBit/s of USB 2.0 is a very thoretical value. It's even more theoretical when you only have a slow thumb drive as Dte mentioned. Those thumb drives only have max read/write speeds of approximately 8-12MByte/s (64MBit/s - 96MBit/s vs the 480MBit theoretical limit) as far as I can remember (haven't checked any performance numbers for USB devices in a while).

So in summary, as we can see from the Tom's Hardware charts, fast external 3.5" USB 2.0 hard drives (not thumb drives!) are only about 2.5 to 2.9 times faster than 100Mbit Ethernet, not 5.0 times. And USB 2.0 thumb drives are usually slower than 100MBit Ethernet.

 

[txa1265]

In theory, yes, but in practice this is by far not true.

Even more so with FireWire 800! Hey, my USB interface is wonderful to my 2GB thumbdrive ... but to back up a whole system ...

 

[Prime Junta]

You're right, I had my head up my ass on this one. Should've done the math before posting.

Come to think of it, it's probably because many years ago I tried to transfer a diskful of stuff over 10 Mbit Ethernet, when something about the OS involved simply choked at some point. Been using external hard disks ever since.

Probably still will, since I'll need to zap them over twice for a system upgrade anyway -- and 2.5x is still the difference between one hour and two and a half hours.

 

[dteowner]

By deleting all the stuff that could be recovered someday elsewhere, I ended up with around 6GB of data to transfer. It wasn't too painful with a 2GB thumb drive. I was able to work the opposite end of each transfer (picking files or setting up folders) during the wait times, so it wasn't too bad. I'm planning on using the DVD burner to make permanent backup of lots of that stuff to save myself future agony.

 

[Lucky Day]

Mo, Mike, GG and PJ you are all talking about direct cable links over these ports right?

I've never had the opportunity to try that with USB or Firewire, mainly because I can never get a cable with the same jack on both ends for the PC and I'm limited on Firewire ports (I only have one computer with them).

I've done crossover cables but after getting a router its just easier to leave all my machines connected to it.

My DVD player and TiVo have optical output jacks for audio. How come we never see those for PC?

 

[Alrik Fassbauer]

Even though USB 2.0 has the faster interface, it is up to 70%(!) slower than Firewire.

USB has a crappy overblown head, as a protocol. Not "lightwight" at all, but rather overkill.

I assume that's why it's so slow.

 

[Moriendor]

Mo, Mike, GG and PJ you are all talking about direct cable links over these ports right?

No, we were talking about external USB 2.0 drives of different flavors (from slow thumb/pen/flash drives to fast(er) regular 2.5" or 3.5" hard drives).
I don't know how fast a direct connection via a USB 2.0 data transfer kit would be but everything I've heard about these USB direct connect solutions/kits was not positive at all.
First, you need to buy the kit which is usually more expensive than a LAN cable (just like with LAN, you can't just use a "straight" cable but you need a USB cable with a special pin arrangement). Then you usually need to install the kit software/driver on both systems and then when you're done configuring things, you end up with a pretty slow and error prone data transfer solution. You're also very limited in the physical distance between the systems since USB 2.0 will only work reliably at 5m (17ft) and less.
It's all just not worth the cost and hassle if you have the option to just buy a crossover LAN cable.
And if speed is really, seriously a big issue then I'd recommend a couple GBit PCI or PCMCIA cards. They are pretty cheap nowadays and thanks to Ethernet's excellent error correction you'll have nearly 100% reliable data transfers at very high speeds all of the time.

 

[Gorath]

Last week I´ve had to use a couple of external USB hard disks to transfer data from one PC to the other. It was a positive surprise: WinXP or Linux - just plug it in and it works. The transfer speed is tolerable on USB 2.0.

 

[Wulf]

Re: [I was trying to directly link my work laptop and my PC.]

I also connect to any other pc through usb connection via a "Prolific" chipped cable. It looks like a standard usb cable but has a module built into the middle which controls voltage, it gives a split screen of the two pc's and normal functions become two-way, eg: copy, cut, paste, delete etc'

Here's a link with explanation...
http://www.cooldrives.com/usb20pcdatrc.html

Here's a link direct to Prolific....
http://www.prolific.com.tw/eng/Products.asp?ID=18

Ask at your local pc outlet/store.

Best regards.