Thinkpads Forum

I've read that the T520 of a certainty does not have USB 3.0.

I've read that the T520 of a certainty DOES have one or more USB 3.0's.

Are folks here equally certain of anything about it?

Lenovo's official specs say: NO
but the confusion for the T520 might be this:

3 USB 2.0
1 eSATA USB Combo (Discrete only)

http://www.lenovo.com/shop/americas/con ... 0-T520.pdf

RealBlackStuff wrote:Lenovo's official specs say: NO
but the confusion for the T520 might be this:
3 USB 2.0
1 eSATA USB Combo (Discrete only)
http://www.lenovo.com/shop/americas/con ... 0-T520.pdf

Unfortunately that PDF is 9 months old.

According the Tabook, no USB3 on T520.

Dredging this out of the depths of obscurity..

The T520 itself has only USB 2.0 ports. However, there are some port replicators and mini-docks that have USB 3.0 ports.

Will a T520 in a dock-with-USB3 be able to use USB3 devices?

I ask because I requisitioned a DisplayLink dual monitor adapter, which requires USB3. I thought the T520 had USB3, but didn't verify before the purchase.

I can probably finagle a dock upgrade (from a 4337-10U to a 4337-15W or better), but if it won't make any difference it's hardly worth it at this point. Since these docks have 5 or 6 USB2 ports and a single USB3 port, I'm wondering if there's a USB3 controller in the dock itself.

If this won't work I guess I'll have to return the USB3 DisplayLink adapter and try to find a USB2 one.

Thanks!

THX-1138 wrote:...I'm wondering if there's a USB3 controller in the dock itself.

Judging by the Lenovo info on this link, it looks like yes, USB 3.0 would be available with machines like the T520, that definitely do not have it natively.

http://support.lenovo.com/en_US/detail. ... igr-4tpjf4

Update/Note: Not sure, continue reading thread...

Not certain about that, see here:
http://forums.lenovo.com/t5/T400-T500-a ... d-p/840651

(I seem to recall other discussions that the USB3 on the docks is just passthrough, and functionality has to be present on the notebook)

But then again, it appears that the referenced comment has been removed from the description page, so maybe?

dr_st is correct, I found some references that indicated that USB 3.0 does not work with models that do not have that natively, like the T510 or T520, so perhaps we will wait for a post from a forum member that has a USB 3.0 supported dock and one of the non-USB 3.0 models, to be sure.

This is a big deal, Lenovo should be clear when marketing these docks! Below is the text that I found from a vendor website.

The odd thing is that the note exempts the T420s model that actually has USB 3.0 natively and doesn't exclude some USB 2.0 only models, very confusing!!! Perhaps some forum members with these items on hand can respond.

Compatibility:
ThinkPad L412*
ThinkPad L420
ThinkPad L430
ThinkPad L512*
ThinkPad L520
ThinkPad L530
ThinkPad T400s
ThinkPad T410
ThinkPad T410i
ThinkPad T410s
ThinkPad T410si
ThinkPad T430
ThinkPad T430i
ThinkPad T430s
ThinkPad T430si
ThinkPad T510
ThinkPad T510i
ThinkPad T520
ThinkPad T520i
ThinkPad T530
ThinkPad T530i
ThinkPad W510
ThinkPad W520
ThinkPad X220
ThinkPad X230
ThinkPad X230i

Notes:
ThinkPad T420, T420s and T520 models, USB 3.0 port on the Mini Dock Series 3 with USB 3.0 will function as a USB 2.0 port.
Thinkpad T430, T430s and T530 models on the Mini Dock Series 3 with USB 3.0 will function as a USB 3.0 port.
The functionality of the T420, T420s and T520 is a limitation of the Intel Chipset not a defect in either the Thinkpad or Mini Dock Series 3 with USB 3.0

underclocker wrote:The odd thing is that the note exempts the T420s model that actually has USB 3.0 natively and doesn't exclude some USB 2.0 only models, very confusing!!!

It's confusing indeed. The T420s (and X220 i7) do have native USB3, but it's a separate chip, not part of the chipset. I could easily believe that the passthrough of USB3 is wired to the chipset, so it would not work. But... here you have someone claiming that the USB3 on the dock for their X220 works just as well as the port on the chassis. Go figure.
http://forums.lenovo.com/t5/X-Series-Th ... -p/1054125

dr_st wrote:

underclocker wrote:The odd thing is that the note exempts the T420s model that actually has USB 3.0 natively and doesn't exclude some USB 2.0 only models, very confusing!!!

It's confusing indeed. The T420s (and X220 i7) do have native USB3, but it's a separate chip, not part of the chipset. I could easily believe that the passthrough of USB3 is wired to the chipset, so it would not work. But... here you have someone claiming that the USB3 on the dock for their X220 works just as well as the port on the chassis. Go figure.
http://forums.lenovo.com/t5/X-Series-Th ... -p/1054125

Without seeing a speed test on a device that can read/write much faster than the 25 MB/sec that USB 2.0 does, I am not buying that user's post.

Everything that I have read and tried suggest that the Renesas USB 3.0 controller does not work with USB 3.0 on these newer docks. These docks with USB 3.0 were released in the Tx30 era, where as already mentioned, USB 3.0 is part of the Ivy Bridge and later chipsets.

What underclocker posted makes it very clear as well, shouldn't be any more confusion.

I recently purchased a Mini Dock Series 3 with USB 3.0 to accompany my X220 i7.

I hadn't seen this thread until after I purchased the dock, but am pleased to confirm that the USB 3.0 port on the dock appears to operate as such.

I haven't been able to do a direct comparison between the USB 3.0 port on the dock and one of the USB 2.0 ports on it as the Western Digital My Passport 1.0 TB drive I'm using is only recognised by the USB 3.0 port for some reason (UPDATE: my Lexar USB 3.0 card reader is recognised when connected to a USB 2.0 port on the dock; I assume, therefore, that the dock doesn't provide sufficient power via the USB 2.0 ports to power the WD drive, although that does work without issue when connected via my UltraBase). I therefore tested it via one of the USB 2.0 ports on the X220 and the USB 3.0 port on the dock.

Performance figures are as follows:

X220 i7 USB 2.0:

Sequential Read : 38.129 MB/s
Sequential Write : 28.820 MB/s
Random Read 512KB : 23.257 MB/s
Random Write 512KB : 28.654 MB/s
Random Read 4KB (QD=1) : 0.526 MB/s [ 128.4 IOPS]
Random Write 4KB (QD=1) : 1.236 MB/s [ 301.8 IOPS]
Random Read 4KB (QD=32) : 0.553 MB/s [ 135.0 IOPS]
Random Write 4KB (QD=32) : 0.878 MB/s [ 214.2 IOPS]

X220 i7 USB 3.0 port:

Sequential Read : 101.932 MB/s
Sequential Write : 101.068 MB/s
Random Read 512KB : 39.472 MB/s
Random Write 512KB : 57.867 MB/s
Random Read 4KB (QD=1) : 0.542 MB/s [ 132.2 IOPS]
Random Write 4KB (QD=1) : 1.231 MB/s [ 300.7 IOPS]
Random Read 4KB (QD=32) : 0.433 MB/s [ 105.6 IOPS]
Random Write 4KB (QD=32) : 0.884 MB/s [ 215.9 IOPS]

Mini Dock Series 3 USB 3.0 port:

Sequential Read : 101.982 MB/s
Sequential Write : 101.282 MB/s
Random Read 512KB : 40.155 MB/s
Random Write 512KB : 59.280 MB/s
Random Read 4KB (QD=1) : 0.533 MB/s [ 130.0 IOPS]
Random Write 4KB (QD=1) : 1.234 MB/s [ 301.3 IOPS]
Random Read 4KB (QD=32) : 0.424 MB/s [ 103.6 IOPS]
Random Write 4KB (QD=32) : 0.917 MB/s [ 224.0 IOPS]

As can be seen from the above, the drive is performing at USB 3.0 speed when connected via the dock. Finally, there are no error messages warning that it can perform faster when connected to the USB 3.0 port on the dock and it appears in the tree in device manager under the Renesas Electronics USB 3.0 root hub, rather than under the Renesas Electronics USB 2.0 hub.

Hope this helps to clarify the situation.

Thank you so much for this research. These are amazing findings.

I assume it means that Lenovo's engineers working on the X220 were smart enough to plan for the USB3 mini-dock, and routed the extra port from the Renesas chip to the docking connector.

I might find it useful later down the road, when the X220 becomes my primary laptop, to supplement it with the USB3 mini-dock.

Now, it may be interesting to see if the T420s is like the X220 in this regard.

Thank you for your kind words