480 Mbs vs 100 LAN

[greggustin]

hmmm
guess I am confused
which is faster?
external USB 2.o HD vs Firewire 400 vs LAN Drive

 

[ray_gillespie]

Not sure what a LAN drive is but if it runs at 100Mbps then it'll be slower than the USB and Firewire drives.

In terms of Firewire vs USB 2.0, in theory the USB 2.0 runs at 480Mbps and Firewire runs at 400Mbps. This doesn't always translate into faster data transfer for the Firewire though - depending on the file type and other factors, the Firewire drive could transfer data at similar or even faster speeds compared to the USB drive. Video files are apparently transferred more quickly via Firewire than USB 2.0. Don't ask me how this works though! 🙂

I hope that helps.

 

[greggustin]

well = . . .
your answer DOES help
as it matched my own thoughts
guess it is just hard to think that a USB port is faster than the LAN?
by LAN drive - guess I mean NAS?
I have 3 home computers
was thinking of designing a home made backup system for all systems using 2 Tb drives (one as LAN backup and one to mirror - hate to lose the backup drive - with all the years of home videos and 1ooo's of digital pix )

 

[Dark Atheist]

gbit would be better - and seeing as gbit cards are cheap as you like, i have 2 in each pc i have (3), all linked together 🙂

 

[lancer]

those supposed cheap 1gb lan external drives are ****e. they dont work and moreover and far slower that usb or firewire, we've had a few in the office and always the same deal.

Personally i'd look into e-sata external drives.

 

[greggustin]

gbit would be better - and seeing as gbit cards are cheap as you like, i have 2 in each pc i have (3), all linked together 🙂

so - using the 'math'
a gigabit is about 2x faster than USB2.0
guess I need to check to see if the 'LAN' drives can handle GigaBit

Personally I'd look into e-sata external drives.

how do I add e-sata to existing PC
do I need a PCI card?
I plan on getting 2 new systems
but still want to use the 3 older ones
(limited sots)

 

[Dark Atheist]

i get about 70meg/sec

 

[lancer]

so - using the 'math'
a gigabit is about 2x faster than USB2.0
guess I need to check to see if the 'LAN' drives can handle GigaBit


how do I add e-sata to existing PC
do I need a PCI card?
I plan on getting 2 new systems
but still want to use the 3 older ones
(limited sots)

if you dont already have esata ports on, yes a pci card is the way to go, you may even be able to connect one to the e-pci expansion port.

 

[X-Istence]

Not sure what a LAN drive is but if it runs at 100Mbps then it'll be slower than the USB and Firewire drives.

In terms of Firewire vs USB 2.0, in theory the USB 2.0 runs at 480Mbps and Firewire runs at 400Mbps. This doesn't always translate into faster data transfer for the Firewire though - depending on the file type and other factors, the Firewire drive could transfer data at similar or even faster speeds compared to the USB drive. Video files are apparently transferred more quickly via Firewire than USB 2.0. Don't ask me how this works though! 🙂

I hope that helps.

Here is a bit of random knowledge. USB is slower than FireWire since USB has an entirely different protocol. Duh!

When two USB devices are talking to each other, really only one is speaking. The other is the spoken to device. For each and every time I speak to a device, it has to give a reply, and it may not speak unless it is spoken to.

So this is what happens:

Host (computer) ---> External drive
external drive    ---> Host
Host                 ---> External drive
external drive    ---> Host

Each and every packet the host sends has to be acknowledged. So now if we want to transfer a lot of data the controller is going to be very busy talking to this one device.

Here is another limiting factor, if I am talking to one device, I can't talk to another device. And other devices since they are not being spoken to can't speak with me.

Whereas FireWire was designed with speed in mind. They implemented what is known as DMA (Direct memory access) which is used by every other part of your system (USB included, but ssshh forget about that for now). DMA allows my network card to accept packets from the network, and push them into memory. It allows my computer to ask for a file from the hard drive, and then have the hard drive push it to memory (no more waiting for the CPU to copy it into memory! Sweet!)

So how does this work for FireWire then?

Host (computer) ---> External drive
external drive    ---> Host
external drive    ---> Host
external drive    ---> Host
Host                 ---> External drive

We have now cut the amount of time that the computer is talking to devices. This has also in the past few years become a security risk. Since DMA allows access to any parts of RAM without any intervention from the host machine, you can use FireWire to read/write to any part of memory you want! This has been used in the past to steal passwords, and unlock Windows machines by overwriting the code in memory that says if the password you enter is valid or not.

DMA was not meant to be used on the outside of a machine, and has since then become a huge gaping security hole. However the speed benefits they bring along with them for external buses like FireWire is absolutely awesome.

Before you start thinking you should just disable DMA and the problem goes away, I am sorry to tell you that without DMA a modern computer would not function anymore.

Getting back to USB and FireWire.

USB uses a tiered-star network. Whenever the host wants to communicate with ONE device on this network the information it sends is sent to EVERY node on the network. Think back to networking 101, hubs are bad. Switches are good. Couple this with the fact that you can't speak unless spoken to, AND all packets have to be acknowledged when received you have a lot of overhead.

FireWire was designed for "dumb" devices. Any node on the FireWire "network" can become a "root node" and control the network so to say. It allows peer-to-peer interaction without the requirement of a computer. Such as to allow a scanner to talk to a printer without the requirement of a PC being in the network.

So theoretically, USB 2.0 should be faster than FireWire 400, but FireWire 400 beats the pants off USB 2.0 any day of the week.

For more information, please take a look at the WikiPedia pages:

http://en.wikipedia.org/wiki/FireWire#Comparison_to_USB
http://en.wikipedia.org/wiki/FireWire#Security_issues
http://en.wikipedia.org/wiki/Universal_Serial_Bus

 

[greggustin]

if you dont already have esata ports on, yes a pci card is the way to go, you may even be able to connect one to the e-pci expansion port.

ok - what is a e-pci expansion port?
I have a Gateway 550GR system

 

[X-Istence]

those supposed cheap 1gb lan external drives are ****e. they dont work and moreover and far slower that usb or firewire, we've had a few in the office and always the same deal.

Personally i'd look into e-sata external drives.

http://en.wikipedia.org/wiki/Serial_ATA#eSATA_in_comparison_to_other_external_buses

Also for NAS devices, don't EVER go cheap. That is just a waste of money. If you have to, set up your own, but use proper hardware.

I am using cheap IDE drives, and a GigBit card, if I am pulling from one drive I get about 40 MB/sec over GigBit, if I have a second drive and I grab another file from it, I get about 80 MB/sec over GigBit, if I grab yet another drive (and I start overloading the CPU trying to read this from the file system and sending it out over the poor PCI interface) I saturate the GigBit pipe.

So really it comes down to implementation.

 

[ray_gillespie]

Here is a bit of random knowledge. USB is slower than FireWire since USB has an entirely different protocol. Duh!

Why should Firewire be quicker simply because it has a different protocol? Surely it depends on the protocol in question! :lick:

 

[LeeJend]

If you want a speed advantage using expansion cards the expansion and MB interface (USB, Firewire, Gig Ethernet) needs to be PCI-e, or PCI 2, not the older PCI.

Plain old PCI is only a 33 mHz transfer rate (parallel), 66 mHz on PCI V2 vs 2 Gbits per lane for PCI-e (1x).

You need the bandwidth of PCI-e or PCI V2 to get the full bandwidth out of the faster interconnections.

 

[lancer]

ok - what is a e-pci expansion port?
I have a Gateway 550GR system

it is the small port next to the pci-e port, i dont' know if all mobo's come with them or not.

but looking here.

http://en.wikipedia.org/wiki/Serial_ATA#eSATA_in_comparison_to_other_external_buses

provided by x you'll see that esata... knocks the doors off firewire or usb.

USB is way slower than firewire. basically the info is sent in blocks at a time, whereas firewire constantly streams the info to the drive.

but ohhhh did you see the usb 3.0..

 

[X-Istence]

Thing to remember, is the fact that while eSata has all that bandwidth available to it, most drives are not able to sustain speeds over 100 MB/sec so a FireWire 800 enclosure will get you approximately the same speed, with the added benefit that it is more likely for a computer to have a FireWire port over an eSata port when transferring from computer to computer.

But you have to evaluate the different standards and devices available to you and make the best decision based on that.

 

[greggustin]

lots of great info
ref if cpu 'talks' to USB and USB has to talk back . . .
then why do we have USB KB/MICE/ETC
sounds like a burden on the system?
and then add in USB scanners and normal external HD
or is all just so fast we do not care

hmmm
some of these MB have pci-e x1 (vs the 16 for the graphics card)
is that the uses for the e-sate connection?

 

[kcnychief]

Had similar thoughts and questions here too -

http://forum.osnn.net/showthread.php?t=92804

Noticed some crazy improvement after I upgraded a few components. Which reminds me, I need to update that thread soon...

 

[X-Istence]

lots of great info
ref if cpu 'talks' to USB and USB has to talk back . . .
then why do we have USB KB/MICE/ETC
sounds like a burden on the system?
and then add in USB scanners and normal external HD
or is all just so fast we do not care

hmmm
some of these MB have pci-e x1 (vs the 16 for the graphics card)
is that the uses for the e-sate connection?

USB stands for Universal Serial Bus. Serial was invented to talk to devices on a bit by bit level, problem was it required an unwieldily 9 pins, and a huge connection. Also, only one device could be used at the same time. We used to have serial mice. Then we moved to PS/2 since it would allow us to interrupt the CPU when new mouse movement came in. In almost all modern hardware that uses PS/2, when the computer freezes (this is particularly true in Linux) you can keep moving the mouse, as that never has to go through the kernel. It is passed straight from the mouse to the hardware video layer (that is right, the cursor on your screen is generated through hardware, in X.org for example you can also turn it into a "soft mouse" which means it is not passed directly to hardware).

So to get back, USB was a replacement for serial devices, and needed to allow multiple devices to be connected. Since serial was a one-on-one communication line, it made sense to implement the same thing in USB. Also, 1.5 Mbps would be much faster than serial, so it was an improvement.

Thing is, since USB was meant to replace serial, the entire protocol was laid out according to that as well. Over serial you have hardware flow control which means if I send a bit, I get a bit back letting me know it transferred correctly.

USB was meant for keyboards and mice, stuff that was not heavy on the CPU, which could be done in the small period of time. FireWire was designed to be used for hard drives and other solutions. FireWire however was a standard created by Apple, and no Intel. Intel created USB. Intel did not want to pay Apple for the royalties Apple charged to use certain parts of the FireWire spec. They started pushing USB, and FireWire was left in the dark on anything but Apple machines. People started using USB and liked the fact that it contained a simple way to tell the host machine what the device is and what it does (this is what allows you to easily connect any thumb drive and have it just work!). The spec allowed it to be extensible, Intel had never imagined it would be used for high speed external hard drives.

You may remember how I mentioned Intel did not want to pay royalties, well that meant that USB was now on every motherboard from Intel, and soon was on every motherboard from the AMD camp. Now, since the this is a huge market, do you want to create a device that does FireWire, thereby foregoing the huge market and just cater to the Mac crowd? No, it makes sense to cater to the biggest market. So USB has been abused ever since to do all kinds of things it was never meant to do. The biggest abuse has been external hard drives. A close second would have to be USB ethernet jacks.

Am I a big fan of USB? Absolutely, it has made it really simple to develop for, and not only that it is an almost drop in replacement for serial, requiring a simple chip to do the conversion work, but I do not like the fact that USB is being pushed for devices that should have FireWire instead. Camera's I am kind of okay with. These days cameras with RAW photo shooting capabilities it is a pain to download over 4 GB of data over USB at any reasonable rate, and be able to start editing immediately.

I was talking to some wedding photographers and they mentioned that they got CompactFlash to IDE to Firewire converters so they could transfer the many hundreds of gigabytes of files in a reasonable amount of time to start on editing/making books as soon as possible.

So USB, it is both good and bad. It has been extended to such an extent that it has become detrimental and people are not happy with it. It is very good at what it was created for, being very plug-and-play but USB hard drives, networking? No.

 

[greggustin]

So USB, it is both good and bad. It has been extended to such an extent that it has become detrimental and people are not happy with it. It is very good at what it was created for, being very plug-and-play but USB hard drives, networking? No.

great overview - thanks - it echoed my thoughts
so . to use big external HD as LAN backups = firewire beats USB
but now, what of the e-sata - or the usb noted above

 

[X-Istence]

eSata was made in the first place for external SATA and would be my choice for new hard drives. It allows the SMART status to be used from the hard drive, and will be the fastest method, and will allow you to boot from the device.

FireWire is the alternative, mainly because most newer computers come with on board firewire and thus it is easy to use. But if you have to buy new hardware anyway, get some eSata loving going. You will not regret it.