Michael O'Keefe wrote:
Is USB now slowly going to replace IDE and many PCI cards?
Yes. Unfortunately. For some reason, I find that USB
drives/cdroms/burners just do not work as reliably as Firewire or SATA.
Funnily enough, we just had this discussion at work.
The HS-USB data rate is it's theoretical maximum transport layer rate.
But with protocol overhead, there's is NO WAY HD's will get 60MB/s
Compare this with Ethernet (100Mbs) or GigE (1Gbps) and TCP. There is NO
WAY you will get 1Gbs TCP transfer. You'd be happy with 80% of that, and
estatic with 90% (in some recent performance tests at work, were able to
squeeze 850Mbs with TCP over GigE). There is a comparison similarity
between the TCP overhead (using buffers, waiting for ACK's etc) as there
is with the HD transfer protocols
You don't want to use TCP for this because almost all of TCP overhead is
set up for *unreliable, shared* transport as opposed to a cable which is
*reliable, dedicated* transport.
Is that 133MB/s or 133Mb/s ?
133 Megabytes per second. However, most drives are limited to around 20
Megabytes per second on continuous transfer rates (about 160 Megabits
per second).
With respect to hard drive interfaces, you really want to use SATA
external or Firewire.
Small capacity (<100 GB *snort, back in my day small was small ...*)
external drives are an anomaly. Flash is about to render them
completely irrelevant. With 2GB flash drives at $170 from Staples and
flash drives on something like a *9 month* Moore's law curve instead of
18, we're going to see 32GB flash drive for $170 in 3 years. At that
point, some of the subnotebook manufacturers should switch over as flash
devices gain power and speed advantages.
-a
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