PC said:
So here's an example:
http://www.ultraproducts.com/applications/SearchTools/item-details.asp?EdpNo=4558957&Sku=U12-40529
Ultra U12-40529 Aluminus 3.5" Internal Card Reader with USB and eSATA -
3 Port USB 2.0, 1 Port USB 3.0, 1 Port eSATA, 6 Slot Card Reader
I can apparently buy that for $35 at a local TigerDirect outlet store.
But can't get any real info on SD compatibility.
Ultra no longer makes this item:
http://www.ultraproducts.com/applications/searchtools/item-details.asp?EdpNo=8210281
ULTRA 3.5" Internal Media Card Reader & Writer - 5 Slots, SDHC / USB,
Black/Grey (U12-42951)
But TigerDirect sells it for $12. It shows this compatiblity:
MS/CF/MD/SD/SDHC/SDXC/MMC/XD/MICRO SD
But in the specs it shows only this:
SDHC
This looks interesting:
Sabrent CRW-FLP2 Floppy Drive w/USB 2.0 Internal Card Reader & Writer
(SDHC & Vista ready)
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=4115642&CatId=630
But again lists SDHC.
SDHC is rated up to 32 gb. Beyond that is SDXC (up to 2 TB).
So I guess what I'm looking for is an internal bay-mounted card reader
that is SDXC capable - and has a USB-2 interface connection to the
motherboard.
Maybe this one?
http://www.newegg.ca/Product/Product.aspx?Item=N82E16820130013
StarTech 35FCREADBK3 USB 2.0 Supports CompactFlash type I/II,
SD/miniSD/microSD/SDHC/SDXC,
MMC/RS-MMC/HS-MMC/MMCmobile/MMCplus/MMCmicro/HC-MMC, MemoryStick, and xD
Picture card. 22-in-1 Card Reader
I can give you my selection algorithm.
You're going for SD, so SD is a must have. A 52-in-1 reader is not
an absolute necessity.
First, I hit up Wikipedia, to get the latest defined specs.
http://en.wikipedia.org/wiki/Secure_digital
I scroll down, and notice UHS-I and UHS-II. Of which, the second standard
has yet to appear.
I notice that Card Readers have USB2 and USB3 interfaces. Selecting
USB3 selects for more recent designs (always being careful to
check for transfer rate reports above 35MB/sec, as proof there
is an actual USB3 chip present).
I go to Newegg and enter "card reader" as a search term, which
brings back hundreds of hits. Then, I type in "USB3" as a search
term, then "UHS" as a search term.
Then, look for something with proper specs.
I can get something for $7.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820208939
Even if the computer has only USB2 ports on it, you can still
use the USB3 adapter. Of the nine pins on the USB3, only four
pins touch when plugged into a USB2 port. The device "throttles"
to the max rate that the USB2 packets can transfer the data
(around 35MB/sec or so).
The reviews for that $7 one, covered up to 128GB. The person
who tested 128GB, noted it was formatted exFAT as received.
And he installed the exFAT patch into WinXP (I did that too).
As for speed, someone tested with something relatively fast,
and got 77MB/sec. That offers indirect proof it really
uses a USB3 chip.
Several reviewer note the adapter gets warm, which is... not good.
Maybe it's got a processor inside the chip or something, as otherwise
50 to 100 mW should handle the high speed I/O.
So my selection algorithm is:
1) Go with the fastest specs on either end of the adapter.
USB3 and UHS.
2) Use the customer reviews to vet the device. The sample
device for $7 does 128GB and 77MB/sec. Stuff without
reviews, then you'd visit the manufacturer site. And
many of those manufacturers offer nothing for specs.
So let's try an "expensive one" at $21. I picked this
because it had 70 reviews, so we can get some specs.
Kingston FCR-HS3.
http://www.newegg.com/Product/Product.aspx?Item=9SIA52Z1JK1606
For the Kingston, we know it's using an internal processor,
because you can get a firmware update for it.
http://www.kingston.com/us/support/...oduct=fcr-hs3&filename=FCR-HS3_Firmware_v0131
The Kingston also comes with a datasheet, which is why I
selected it. (I would have selected Startech brand, if
there was one, because they sometimes report the actual
chip used in a product, making it easier to track down
real specifications.)
http://www.kingston.com/datasheets/fcr-hs3_us.pdf
They give no capacity information.
Secure Digital
- SD
- SDHC
- SDHC UHS-I
- SDXC
- SDXC UHS-I
So then I have to go back to the Newegg reviews for proof.
"75MB/sec
randomly drop from the file explorer...
try a new cable, and everything started working
not UDMA7 (for CF)
"
The general flavor from the other reviews, is these
new adapters can have significant differences between
read and write. Perhaps more of a difference than
can be accounted for in the flash chips themselves.
I have a Transcend USB2 adapter for SD, and given the
constraints of USB2, haven't been disappointed. But
only tested with a 32GB SD, formatted FAT32 and not
exFAT.
And when there are only a small pool of products
of this type, there might not be that many underlying
USB3 chips used in the designs. If there was a
wider selection of chips, there would be hundreds of
these things. The selection terms only uncovered
26 products.
Paul