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发表于 2014-12-27 11:38:27
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小白 发表于 2014-12-27 11:07
USB原理不靠谱?胡说八道。USB也好,火线也好,都是传输数据的方式而已,只要不会造成误码,就是靠谱的方 ...
我摘录了int202关于firewire vs usb的表述,请白版读一下。
说到速度问题,usb2.0的理论速度是480MBPS,蓝光的最大理论码流是48MbPS,也就是同时传输10部蓝光USB2.0都无问题,我不知道为什么白版会对传输音频信号的速度有异议。
说明书的大致意思有几点:——专业英语比较强的烧友帮翻译一下最好。
1、火线是个对等协议,每个设备都有一个火线专用IC,相比USB,火线都是硬件实现传输,PC的CPU负载很低——对音质影响小。
2、火线的工作方式比USB更可靠。
Firewire vs. USB
Firewire is a peer-to-peer protocol, meaning that e
very device on a Firewire network is equally ca-
pable of talking to every other device. Two video c
ameras on a Firewire network can share data with
each other. A Firewire audio interface could save s
ound data directly to a Firewire hard drive. Your
computer is just another peer on this network, and
has no inherent special status.
Firewire is always implemented in hardware, with a
special controller chip on every device. So the
load it puts on your CPU is much lighter than USB c
ommunications load, and you're much less likely
to lose any sound data just because you're running
fifteen things at once. Specialized hardware
usually makes things faster and more reliable, and
this is one of those times. But the real reason
Firewire is more reliable than USB is more fundamen
tal than that. It's because Firewire allows two
operating modes. One is asynchronous, similar to wh
at USB uses. The other is isochronous mode,
and it lets a device carve out a certain dedicated
amount of bandwidth that other devices can’t
touch. It gets a certain number of time slices each
second all its own. The advantages for audio
should be obvious: that stream of data can just kee
p on flowing, and as
long as there isn't more bandwidth demand than the
wire can handle (not very likely) nothing will
interfere with it. No collisions, no glitches. From
a practical perspective, this also makes it safer
to
send a lot more audio via Firewire. That's why most
of the multichannel interfaces (18 channels, 24
channels, etc.) are Firewire devices, and USB devic
es usually just send a two channel stereo signal.
For hooking up your mouse, keyboard or thumb drive,
USB is plenty fast and plenty cheap. For hard
drives, either one will do (although Firewire is so
mewhat more reliable). For audio devices, USB will
do fine if no other devices are competing with it a
nd if you have processor room to spare. But Fire-
wire will always be able to handle more load with l
ower latency and no glitches, because it has re-
sources it can set aside to make sure your audio ge
ts where it needs to go.
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