Why do FireWire interfaces STILL use FW400? Why not 800?

[theblotted]

because FW400 is plenty fast already.

i don't have exact numbers here with me, but the bottleneck at that point i believe is HD and bus speeds.

techies correct me if i'm wrong here.

[AASteveo]

RME Fireface 800 from zZounds.com!

Wow, looks like I'm wrong. Just found the RME FireFace that also has 800.

[shanabit]

FW is going to be bye bye. USB3 will replace it IMO

[blaugruen7]

hmmm....


does usb3 has bidirectly data flow or how it is called?

i think this is the great advantage of firewire over usb...

[warmer]

that fireface 800 only uses firewire 400 unless you are connecting units together. As has been said, the bandwidth isn't needed.

[theblotted]

Originally Posted by warmer

that fireface 800 only uses firewire 400 unless you are connecting units together. As has been said, the bandwidth isn't needed.

yup.

i only use FW400 on my FF800 for the 3 years i've had it. works fine, never had a bottleneck issue.

moreover, i think FW400 and 800 doesn't play well together at the same time. i've also got M-Audio FW1814 on a PCIe FW card, and using all FW400 seems to be more stable.

[blueguitarbob]

techies correct me if i'm wrong here


Respectfully, there is some incorrect information here.

First, with regard to speeds, Firewire 400 is not terribly quick by today's standards. It's max data transfer is 400 Mbits/sec, which is just under 50 MB/sec. Note the units change there... bits vs Bytes. Roughly 8 bits per byte. Firewire is defined in Mbits/sec, while most modern devices specify data transfer in megabytes per second (MB/sec).

So, is 50 MB/sec "fast enough"? It depends what you are doing, I guess. However, modern hard drives can easily exceed that transfer rate, both peak and sustained transfers. If you are using a recent hard drive on a FW400 bus, you are probably limiting the transfer rate. That may or may not be a problem.

For example, I use external RAID0 arrays on FW800 for Pro Tools, and I can test the drives at 80-90 MB/sec sustained transfer with no problem. Do I need that bandwidth? Yes. Depending on the number of tracks, the sessions sometimes reach the transfer limit when connected via FW400.


Second, you can mix devices of different speeds on a FW800 bus. As long as the maximum limit of the bus is not exceeded (just under 100 MB/sec), each device is independent. Connecting a FW400 device does not slow down a FW800 port. That's part of the design specification.

That's completely the opposite of USB2.0, by the way, which may be where the confusion comes from. A USB2.0 port is limited in speed by the slowest device on the chain. They fixed that in the USB3.0 specification (which is closer to Firewire in basic design).

You need to be smart about physically connecting devices, however. If you have a FW800 port, the FW800 devices all need to be connected directly to it via the larger connector. The FW400 devices need to be at the end. This, for example, will not work:

FW800port--->FW400drive--->FW800drive

Well, it will work, but both drives will be at FW400 speeds. Do this, and both drives will be at their maximum transfer speed:

FW800port--->FW800drive--->FW400drive



So why don't more computer manufacturers put in FW800 ports instead? I think it requires a higher licensing fee, and I also think the parts are slightly more expensive. Apple can do it because they are one of the original Firewire patent holders, but everybody else needs to pay a licensing fee to include a Firewire port.

If you want a FW800 port, I recommend Unibrain products:

Welcome to Unibrain web site - The Firewire (Firewire 800 - IEEE 1394b) Innovators

Their newest PCI and PCIe cards are very good:

FireBoard 800-e™ 1394b (Firewire-800) OHCI PCI Express adapter

FireBoard-800™ V.2 1394b (Firewire-800) OHCI PCI adapter


And yes, a standard 32-bit PCI slot is enough for FW800. Unless you have other high-bandwidth PCI cards in your system (RAID controllers, for example), the PCI bandwidth of 133MB/sec will be sufficient to supply a FW800 card.

[blueguitarbob]

I mentioned USB3.0 briefly, but I should say that it will probably replace FW800 starting in 2010. The specification moves it very close to Firewire, while maintaining backward compatibility with earlier USB devices. It's looking very good. FW800 will be around for a couple years, however.

Also, eSATA should be considered, as it's speed (300MB/sec) is the fastest interface that you can currently buy at reasonable prices. If you are buying an external hard drive for your own use, I recommend it.

However, the use of eSATA is not widespread, so you can't count on being able to plug that drive into anyone else's computer (unless your drive has multiple interfaces). In the studio world I share drives with, FW800 is the standard. Nobody has asked me about eSATA yet.

[theblotted]

bgb,

thanks for the detailed explanation and clarification.

i do know however, from experience, that FW400 and 800 devices don't play well with each other. stability jumps out the window. i'm not doing any daisy chaining. on the same devices, when i use all FW400, i find that i get less crashes, etc.

regarding eSATA, am i the only person who find the connector is real flimsy, and it doesn't "lock and hold" that well compared to USB or FW? i feel like if i lightly bump it, the connector falls out of its socket.

speed for eSATA is great, i use it with my mobile PTLE system and LaCie external HD. still waiting for an interface to show up with eSATA connector.