Thinkpads Forum

These are the best bandwidth numbers I could find. Can anyone confirm that they are true? My assumption is the ultrabase is nothing more than a USB 2.0 repeater. If this is the case, it make the X301 more attractive if you want to hook it up to a monitor while in the office.

What I don't know is how much bandwidth do you need to have a X200/X301 desktop to be displayed in a 1900x1200 24" monitor?

Rough calculation: 1920 x 1200 x 32 bits @ 60 Hz = 74 Mb/s. Somehow I think you will be OK with 480 Mb/s.

tomh009 wrote:Rough calculation: 1920 x 1200 x 32 bits @ 60 Hz = 74 Mb/s. Somehow I think you will be OK with 480 Mb/s.

I got 442 Mb/s from that calculation, but it's still within the range of the ultrabase bandwidth, so I don't think you have any problem.

AvalonXIII wrote:I got 442 Mb/s from that calculation, but it's still within the range of the ultrabase bandwidth, so I don't think you have any problem.

How did you get that? 1920 x 1200 x 32 x 1 gives me 74 Mb/s ...

tomh009 wrote:
How did you get that? 1920 x 1200 x 32 x 1 gives me 74 Mb/s ...

Don't you also multiply by 60Hz? The unit only works out if you multiply by the refresh rate. bit*Hz = bit/sec.

Here's a useful tool in calculating bit rate:
http://web.forret.com/tools/video_fps.a ... 4&depth=32

AvalonXIII wrote:I got 442 Mb/s from that calculation, but it's still within the range of the ultrabase bandwidth, so I don't think you have any problem.

That's because you left a 0 out there somewhere. The real answer to this calculation is 4.42Gbps. Of course, it does not account for compression, overhead etc.

The maximum bandwith useable by DisplayPort, at the maximal resolution of 2560x1600, with audio and control overhead is indeed ~10Gbps.

Then again, I would be very surprised to learn that the Ultrabase is nothing but a USB repeater. This is not the case with any previous docking stations by Lenovo. The pins go straight to the motherboard, and the dock is not recognized as a USB device of any kind.

You're right dr_st the ultrabase connects via a PCI Express slot to the motherboard. My bad. This gives the theoretical bandwidth of 2.5Gb/s for any point to point connection.

Thanks to all that replied.

AvalonXIII wrote:Don't you also multiply by 60Hz? The unit only works out if you multiply by the refresh rate. bit*Hz = bit/sec.

Duh, you are right ...

beaker wrote:You're right dr_st the ultrabase connects via a PCI Express slot to the motherboard. My bad. This gives the theoretical bandwidth of 2.5Gb/s for any point to point connection.

That's assuming it's a single-lane (PCI-E 1x) connection. If it's PCI-E 4x, it can be 10Gbps. But I don't know which it is.

tomh009 wrote:
Duh, you are right ...

I misread an order of magnitude, so I'm not that better than you