Everything You Need To Know About Thunderbolt

Active Thunderbolt Cables Are Hot Cables

You might not think that an external connectivity solution would have thermal issues to worry about, but Thunderbolt is quite literally a hot technology.

An infrared image of where a Thunderbolt cable plugs into our motherboard reveals temperature readings above 110o F, even when downstream devices are idle. Active, we see the cable exceed 120 degrees.

Of course, those temperatures are a result of the active Thunderbolt cable, with two Gennum GN2033 chips on each end. As information moves through the cables, the hard-working data transmission chips heat up and cause those more extreme readings.

Not surprisingly, more space-constrained applications, like our 13.3" MacBook Pro, demonstrate even more alarming thermal properties. In the shot above, the Thunderbolt cable is the one up in the 120o+ range. Next to it, on the left, you can see a FireWire 800 cable. On the other side, there's a USB 2.0 cable. Although those two interfaces look like they're giving off heat as well, they're actually being warmed by the Thunderbolt cable. Fortunately, only the ends of the cable heat up; everything in between stays cool.

Those lofty temperatures aren't a problem if you're using a mini-DisplayPort adapter. The display signal is already demuxed by the controller before it hits the adapter.

So, in comparison to USB and FireWire, Thunderbolt cables get pretty darned hot. But the heat dissipated only causes the plug to become uncomfortable to handle for any significant length of time, and they won't burn you (the same conclusion we reached about gaming on an iPad 3 at maximum brightness).

  • Pyree
    I was really hoping to see some eGPU benchmark. Oh well, I guess I have to wait.
  • mayankleoboy1
    thunderbolt will fail after external PCIE standard is implemented
  • mayankleoboy1
    for more insight of thunderbolt fail and Intel's lying :

  • shoelessinsight
    Active cables are more likely to have defects or break down over time. This, plus their high expense, is not going to go over well with most people.
  • A Bad Day
    Looks like I'm going to steer clear of Copperpeak for my future build.
    Cost is going to kill this.
  • mayankleoboy1
    because "thunderbolt" sounds much sexier than "HDBaseT " ?

    and with apple, its all about the sexiness, not functionality/practicality.
    Prediction: We will see Thunderbolt available on SmartPhones. When we do, this port will be able to handle a monitor, external hard drives, speakers and many other USB devices through its Thunderbolt docking station. Obviously a SmartPhone won't need to be attached to a webcam. This will become the future desktop...that is, if it can run Crysis. LOL Had to add that in there. :)
  • pepsimtl
    I remenber scsi interface ,so expensive ,just the company (server) use it .
    and sata interface replace it.
    For me Thunderbolt is the same song
    I predict a sata 4 (12gb) or usb 4 ,soon
  • archange
    Hot, expensive active cables cannot be anything else than niche.