s|b said:
Were some of those thumb drives USB 3.0?
I have a Lexar S73, which is a cheap USB3. I got it for around $20
or so. It does only 45MB/sec on USB3, but when plugged into a USB2
port, it actually does 35MB/sec. Whereas one of my hard drive USB2
enclosures, does slightly less than that. So to me, the new wave
of USB3 drives are actually interesting. They've managed to get
a bit more from a USB2 port, than a USB2 device can.
The writes are probably still shy of being flat out, but they're
getting there.
This is much better than a "Sandisk Ultra 8GB" USB2 flash I got at a Staples,
which works in spurts, and only managed 4MB/sec or so. Since I bought
them on the same day, from two different stores, the comparison between
them is truly pathetic. Sandisk should be ashamed of themselves.
Both USB flash devices cost around the same, but the Lexar S73
happens to have 4x the capacity, and ~8X the speed. I think
the worst part, is Sandisk would use the word "Ultra" to describe
the product. Marketing *fail*.
And you can do better on USB3 devices plugged into USB3 ports.
Patriot makes some fat-body USB3 flash keys, which have
somewhere around 100MB/sec or so. The fat-body is needed to
support more flash channels, which is how those things
get their speed. So if you want something faster, look
for a key which is physically bigger.
The USB3 keys, work in both USB3 and USB2. Since all my hardware
is USB2, I've been testing my USB3 key in only USB2 computers.
The 45MB/sec quoted above, is the rated speed, and I couldn't
test that. I still don't have any USB3 ports.
*******
In terms of booting from USB3 on USB3, very few chipsets have
native USB3 ports on the Southbridge. Intel delivered theirs only
very recently. And AMD didn't put it on all their product lines.
Many motherboards, the USB3 comes from a NEC, Asmedia, or other
brand of chip, and when that happens, it might not support booting
via those ports. It really depends on the BIOS design. In the past,
the rule of thumb was, that only ports directly on the Southbridge,
had good coverage at boot time. (Storage chips are OK, because they
ship with Extended INT 0x13 bios code modules, but things like USB3
chips, I don't think they come with any support code the motherboard
maker can use. That's why they'd be a problem.) There would be
no problem booting from a USB3 flash stuffed into a USB2 socket
which is actually hosted by the Southbridge. So if you notice
some permutations and combinations don't work for booting,
that could be why - they're hosted by two different chips.
And BIOS designs have never been that good, at supporting
all hardware on board, to the same level. And that's why
"integrated ports" on the Southbridge, are so valuable.
Paul