Thinkpads Forum

Has anyone seen these Transcend Express Card Reader for SD/SDHC/SDXC/UHS-1 (TS-RDF1) floating around for sale,
https://www.amazon.com/Transcend-Expres ... op?ie=UTF8
apparently they tap the pci-e bus and are much faster than the internal SDXC readers on the laptops. Admins if you feel this will get more visibility in from another section of the forum feel free to move it.

I can confirm the speed of my T500's reader is too slow for SDHC. 10mbps read / write is alright for a little 4GB SD, but for large files on an SDHC card it's just stupid. An SDHC to USB 2.0 adapter is 2 times faster than the internal reader.

Depends on which laptop. I believe the ones on **20 series and newer are SDXC/UHS-1 capable; previous generations are not.

dr_st wrote:Depends on which laptop. I believe the ones on **20 series and newer are SDXC/UHS-1 capable; previous generations are not.

I know the x220's are SDXC capable, but I don't think they can achieve UHS-1 speeds since the reader is connected to the USB 2.0 bus?

The reader is connected to PCIe bus, and can achieve UHS-1 speeds. Confirmed be my personally.
http://forum.thinkpads.com/viewtopic.ph ... 73#p728124

I don't recall any Thinkpad where the reader is connected to USB bus. Even before PCIe they were using PCI (e.g. X61).

dr_st wrote:The reader is connected to PCIe bus, and can achieve UHS-1 speeds. Confirmed be my personally.
http://forum.thinkpads.com/viewtopic.ph ... 73#p728124

I don't recall any Thinkpad where the reader is connected to USB bus. Even before PCIe they were using PCI (e.g. X61).

Hm, thanks for the correction, I wonder why read speeds are so slow tho.

In my tests they were not slow at all...

As far as I can see, you still did not mention things like what laptop model you are using, and what SD card model. This is important information, you know.

Whoops, I meant to say write speeds were slower than the external readers, I have a x220t btw, still be kinda nice to find that transcend reader, it sits flush and so do the SD cards, a rare find apparently, and will still be useful as SDXC is planned to support 2TB capacities eventually.

The actual read/write speeds depend on the SD controller itself. As you can see, read speeds of the built-in controllers were comparable to the external USB 3.0 reader, but write speeds were slower. Without knowing which chip is in that TS-RDF1, and without someone posting verified numbers, it's hard to know how fast it will be. I agree it would be nice to obtain one, for testing.

So why do you think the write speeds on the internal x220 SD port are slower than the external ones?

I don't know.

dr_st wrote:I don't recall any Thinkpad where the reader is connected to USB bus.

ThinkPad X201, X201 Tablet, X201s: 0bda:0159 bcdDevice 58.88.

Digitalhorizons wrote:SDXC is planned to support 2TB capacities eventually.

SD 2 (marketed as 'SDHC') is "planned to support" 2 Tio "capacities". 'SDXC' is just a marketing word, means "exFAT filesystem". 'SDXC' is not about hardware. 'SDHC' means "storage addressable up to 32-bit (4294967296) × 512 octet = 2 Tio".

dr_st wrote:Without knowing which chip is in that TS-RDF1, and without someone posting verified numbers

JMicron JMB389, 74 Mo/s read (Hans-Jürgen Reggel demonstrated)

automobus wrote:JMicron JMB389, 74 Mo/s read (Hans-Jürgen Reggel demonstrated)

74? I saw 70.81 as the highest in that table. Maybe I missed something? In any case, the write speeds are pretty poor. I don't if it's the cards, or the reader, but so far I see nothing to suggest it offers any advantage over the UHS-I capable built-in readers in Sandy Bridge / Ivy Bridge Thinkpads.

automobus wrote:ThinkPad X201, X201 Tablet, X201s: 0bda:0159 bcdDevice 58.88.

Interesting and surprising, considering that the T410 has a PCIe reader. Do you know about X200?

dr_st wrote:74? I saw 70.81

Hans-Jürgen Reggel's use of 'MB/s' means 'Mio/s'. 70.81 Mio/s × 1.048576 = 74.25 Mo/s.

> write speeds are pretty poor. I don't if it's the cards, or the reader

It's cards and year 2011. On The River, a 2011 review mentions '90MB/sec read' and a 2012 review mentions 'writing at about 65MB/s'.

> Do you know about X200?

I do not know first-hand. I searched WWW and conclude, it is USB: 05ca:1880 bcdDevice 0.01.