FireWire Spec to Boost Data Speeds to 3.2 Gbps 223
Stony Stevenson writes "A new set of data transfer specs may reach new Firewire speed records. The new transfer version is called S3200 and builds on the earlier specification approved by the IEEE.' The technology will be able to use existing FireWire 800 cables and connectors while delivering a major boost in performance. The new spec also will let users interconnect various home-networking appliances via coax cable, linking HDTVs with set-top boxes, TVs, and computers in various rooms around a home or office. The new release enables the transmission of FireWire data over distances of more than 100 meters. Home entertainment centers are likely to be an early application.'"
Re:I think Apple.... (Score:3, Informative)
You're thinking of IEEE1394, which it still is. And Sony's iLink implementation was the unpowered 4-pin version of it.
compared to sata 3Gbps (Score:3, Informative)
Re:I would just like a single standard... (Score:5, Informative)
Re:I would just like a single standard... (Score:5, Informative)
Whereas 1394 is device-centric - designed for tranferring video, audio, data, etc. between "dumb" devices.
The PC world "snubbed" 1394 (not completely) because of the $.25(or something equally absurd) royalty to Apple; Intel pushed USB.
1394 is more expensive to implement in hardware (which should be obvious - it's for dumb devices!), while USB is cheap - the CPU does most of the work.
Re:Why still no optical link? (Score:2, Informative)
Re:I would just like a single standard... (Score:5, Informative)
Here are the technical specs for Firewire from Wiki:
FireWire can connect up to 63 peripherals in a tree topology (as opposed to Parallel SCSI's Electrical bus topology). It allows peer-to-peer device communication -- such as communication between a scanner and a printer -- to take place without using system memory or the CPU. FireWire also supports multiple hosts per bus. It is designed to support Plug-and-play and hot swapping. Its six-wire cable is more flexible than most Parallel SCSI cables and can supply up to 45 watts of power per port at up to 30 volts, allowing moderate-consumption devices to operate without a separate power supply. (As noted earlier, the Sony-branded i.LINK usually omits the power wiring of the cables and uses a 4-pin connector. Devices have to get their power by other means.)
FireWire devices implement the ISO/IEC 13213 "configuration ROM" model for device configuration and identification, to provide plug-and-play capability. All FireWire devices are identified by an IEEE EUI-64 unique identifier (an extension of the 48-bit Ethernet MAC address format) in addition to well-known codes indicating the type of device and the protocols it supports.
From the USB wiki:
USB was originally seen as a complement to FireWire (IEEE 1394), which was designed as a high-speed serial bus which could efficiently interconnect peripherals such as hard disks, audio interfaces, and video equipment. USB originally operated at a far lower data rate and used much simpler hardware, and was suitable for small peripherals such as keyboards and mice.
The most significant technical differences between FireWire and USB include the following:
* USB networks use a tiered-star topology, while FireWire networks use a repeater-based topology.
* USB uses a "speak-when-spoken-to" protocol; peripherals cannot communicate with the host unless the host specifically requests communication. A FireWire device can communicate with any other node at any time, subject to network conditions.
* A USB network relies on a single host at the top of the tree to control the network. In a FireWire network, any capable node can control the network.
These and other differences reflect the differing design goals of the two buses: USB was designed for simplicity and low cost, while FireWire was designed for high performance, particularly in time-sensitive applications such as audio and video. Although similar in theoretical maximum transfer rate, in real-world use, especially for high-bandwidth use such as external hard-drives, FireWire 400 generally has a significantly higher throughput than USB 2.0 Hi-Speed.[13][14][15][16] The newer FireWire 800 standard is twice as fast as FireWire 400 and outperforms USB 2.0 Hi-Speed both theoretically and practically.[17]
There are technical reasons why USB 2.0 devices cannot efficiently utilize all the available bandwidth. USB communication is based on polling the devices; there is no pipelining of commands. After sending a command to a device, the USB host must wait for a reply to the command before a new command can be sent to the same device. The bandwidth of a USB bus is divided by all devices connected to the bus. The USB host cannot send commands to one device while waiting for reply from another device. Since all communication is initiated by a USB host, the host must periodically poll all those USB devices that can provide data at unexpected intervals, such as network cards and keyboards. This consumes unnecessary resources when the devices are idle. These issues are being addressed by the forthcoming USB 3.0 specification, although it is not clear whether USB 3.0 is going to match FireWire in bandwidth efficiency.
Re:I think Apple.... (Score:5, Informative)
I've got a drive with USB 2.0, FW400, FW800, and eSATA connectors. (It's a LaCie "quadra," if anyone is interested.)
In terms of performance, that's pretty much the order, there -- USB is slow, despite it's claims of 480mbits/sec. FW800 and eSATA get me about 85MBytes/sec reading from the raw device; writing appears to be a bit slower, but that was going through the filesystem, so I'll do another test on a drive I don't mind wiping out :).
As with SCSI, the big advantage the faster FW speeds have is that you can have multiple devices chained. So you can have six or seven disks on the chain, and not worry about running out of bandwidth. eSATA doesn't give me that advantage.
Re:I would just like a single standard... (Score:5, Informative)
One of the big advantages FW has over USB is that a device can request, and get, a specific bandwidth. So, for example, a video camera can say, "I need to have 19mbits/sec." And if it can, then it'll get that -- and nothing on the bus will be able to take it away until it releases it.
When doing real-time applications such as video, this is pretty important.
Re:Yeah -- so what? (Score:2, Informative)
FW800 is backwards compatible with FW400. The connector, however, is not.
This is a good thing, because the FW800 connector will be the same one used for FW3200 (or whatever it ends up being called :)).
You can, however, get an adapter pretty easily and cheaply. This will allow your FW800 device to plug into your FW400 chain (and run at 400Mbits/sec)... or your FW400 device to plug into your FW800 chain (and, while it will run at 400Mbits/sec, your FW800 devices will still be able to run at 800Mbits/sec!).
You can also run FW800 over Cat5 cable, and there are small, plastic, optical cables available for it. (The auto industry uses FW quite a bit -- or did, anyway, I'm not sure if they're still using it. The real-time capabilities were very important to htem.)
Re:I would just like a single standard... (Score:3, Informative)
Each device on a USB bus have to get equal bandwidth slices.
Re:I would just like a single standard... (Score:5, Informative)
The highest copy speed I have ever reached on FW400 is 32MB/s - limited by the ATA33-FW400 bridge chip (Oxford 911) while the highest speed I have ever seen with any combination of my USB2/480 external HDD boxes and PCs is 24MB/s with 18MB/s being more typical. Under the best circumstances, USB barely matches the SLOWEST speeds I take for granted on FW400. If I string two of my FireWire drives together and move data between the two boxes, I still get the same 24-30MB/s I am used to but if I try to do the same with USB2 and a hub, USB2 crawls at 8-10MB/s. In this scenario, FireWire is as much as 3X as fast as USB2.
With eSATA for external storage, USB3 (late 2008) for all sorts of high-bandwidth (4.8Gbps) devices and GbE for mainstream networking, FW3200 will become irrelevant soon enough: USB3 is supposed to be 4.8Gbps double-simplex fiber, blowing away FW3200 on raw speed and finally getting rid of USB1/2's half-duplex overhead.
Re:I think Apple.... (Score:3, Informative)
Re:Why still no optical link? (Score:3, Informative)
Re:Yeah -- so what? (Score:3, Informative)
I've seen the mini firewire port on many notebooks. I think the problem with puting the six pin port in it is that it would allow the device to consume power and that's not necessarily desirable when everything has to be so small and allowing more power to power a high-draw FW device can be a problem.
I think eSATA is the replacement for Firewire in many of its previous niches other than video decks and camcorders. It helps that it really doesn't require a controller chip on both ends of the cable, and it should be exactly as fast as it would be if it were an internal drive. But eSATA is for only one drive per port, port multipliers are still an expensive and rare exception.
Re:I think Apple.... (Score:3, Informative)
Re:HDTVs and set-top boxes people (Score:1, Informative)
I dont know where you buy your cables, but you should try monoprice.
$6.43 HDMI 1.3a Category 2 Certified Cable 28AWG - 6ft w/Ferrite Cores (Gold Plated) - YELLOW
Re:I would just like a single standard... (Score:3, Informative)
I wouldn't assume that USB3 will do much at all. If it doesn't require a more intelligent bus controller to offload the work, it will be torture on the CPU at those speeds, and if it does, a lot of manufacturers will reject it because it costs too much more to build cards for it, and a lot of users will reject it because of the substantial extra expense of the cards compared with other technologies. Similarly, for external devices, cost will probably play a more important role in driving adoption than any other factor, since neither USB3 nor FW3200 would be present in existing computers. To that end, FireWire has a major leg up on USB3. There's at least a possibility that it would require nothing more than a silicon change. Same connectors, same basic technology, same basic board layout, etc. USB3 will require new, upgraded connectors (optical) in order to reach those speeds, which presumably brings additional board layout requirements for extra traces, etc.
The reason you got so much better performance with FireWire is that you don't use any CPU power with FireWire. DMA from your hard drive goes straight into the host's memory without the CPU lifting a finger (except to ACK an interrupt and let the higher layers of the software stack know that data has been delivered). It's a similar story for audio and video. If your driver is written correctly, DCL programs running on the FireWire host controller do all the data copying for you without the CPU being involved except to receive a notification that data is ready. Compare that with USB audio which is an endless disaster because the CPU has to service it reliably and predictably, time stamp everything precisely, etc.
I don't see USB replacing FireWire for professional audio/video applications any time soon. It just isn't up to the task, and the additional parts cost of bringing it up to spec would eliminate the sole advantage USB has over FireWire: cost. For disks, USB 3 could replace FireWire if and only if they put true DMA support into the host silicon. Unfortunately, such a change would not only increase the host silicon cost, but also might increase the cost of the device silicon significantly as well, which would be a disaster for USB.
Note: I haven't read any specifications for either USB 3 or FW3200. I'm basing this off just a handful of articles on the subject and interjecting my opinion of the likely hardware costs. This is, of course, largely conjecture until such time as both technologies reach final silicon.
Re:Better yet.... 3.0 (Score:3, Informative)
Re:I think Apple.... (Score:3, Informative)
Not only that but also USB networking requires special software. Linux/WinXP/2K/98 all do FW networking out of the box. Vista does NOT, however, so keep that in mind if you need it.
Re:I would just like a single standard... (Score:3, Informative)
If you really wanted to blame someone, you can at least partially blame Steve Jobs. Wikipedia [wikipedia.org] mentions that one of the reason Firewire wasn't as popular as USB was the high licensing and manufacturing costs compared to USB. (One of the IP owners is Apple). This gentleman [teener.com] mentions that just when Apple was going to give away licenses for a fairly cheap price (1997 or something), Steve came back to Apple and decided that maybe they should charge more. This made everyone unhappy (including Intel) and the rest is history.
I suppose nobody will read this as the topic is pretty old now, but oh well.
Re:I think Apple.... (Score:3, Informative)