Promise Pegasus R6 & Mac Thunderbolt Review
by Anand Lal Shimpi on July 8, 2011 2:01 AM ESTTarget Display Mode with an iMac
In our 2011 iMac review I mentioned that you could use the new iMac as an external display if, and only if, you had a Thunderbolt cable connecting it to a 2011 MacBook Pro. When I reviewed the iMac, you couldn't buy a Thunderbolt cable. Now you can.
The process is pretty simple. Just connect any 2011 MacBook Pro to any 2011 iMac via a Thunderbolt cable. Hit Cmd + F2 on the iMac's keyboard and boom, your brand new iMac is now a secondary display for your MacBook Pro. Note that you need a modern Apple keyboard for this to work. Older Apple keyboards and some non-Apple keyboards won't send the right key code and will refuse to activate target display mode on the iMac.
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The iMac has to be fully powered on when this happens. You do lose all keyboard/mouse support on the iMac, however the machine doesn't go to sleep when in this mode - it'll remain on, although likely in a low power state. Any applications you have open on the iMac will remain open. Any music playing on the iMac will continue to play and you don't get use of the iMac's speakers from your MacBook Pro.
15-inch MacBook Pro (2011) + 27-inch iMac (2011) running in Target Display Mode
For 2011, this is admittedly an odd usage model. I'm not sure how many people want to connect their brand new MacBook Pro to a brand new iMac and use the latter as just a display. Down the road I can see this being a good feature as it lets you upgrade to faster MacBook Pros and still use your iMac as a larger display if you'd like.
I would prefer it if the iMac allowed itself to boot into a minimal environment where only the display and necessary ICs were powered, leaving the CPU, GPU, hard drive and the rest of the system mostly powered down. I suspect Thunderbolt complicates this as the controller needs a number of components powered up before it'll function. Perhaps future versions of the iMac can find a way around this limitation however.
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enthios - Thursday, July 28, 2011 - link
"Ironically isolated from the world around them?" How about wifi and iCloud? With limited storage capacity, there's no need for anything more. iOS devices are simply thin clients - and they work wonderfully as such.NirXY - Friday, July 8, 2011 - link
Which is 0$Exelius - Friday, July 8, 2011 - link
Yes, but in this instance, it's not just a dumb wire; there is an IC at each end of the cable. So theoretically, if Intel comes up with an upgraded Light Peak spec, there may well be cables that are capable of faster speeds. I also imagine longer cables become more difficult, and may in fact require fiber optic transceivers built into the cable. This cable also likely costs significantly more to manufacture than a crimped cable, since there's a tiny IC and micro soldering that needs to be done on each cable.But yes, in one sense you are right that in a digital bus, higher quality cables do not provide better performance (though I have run into very low-quality HDMI cables that work fine at 720p but refuse to carry a 1080p signal.)
repoman27 - Sunday, July 10, 2011 - link
At the moment, i’m not sure the Thunderbolt host controller has any real legs on the cable. That host controller is already pumping data to each port at the same speeds as the DMI link between the CPU and PCH. Everything in the chain that is connected to it needs to get faster for Thunderbolt to get faster, i.e. PCIe 3.0, DMI 3.0, DP 1.2.Also, I’m pretty sure it’s not those little ICs that are making Apple’s Thunderbolt cables cost $49. Like many retailers, Apple knows that cables and accessories (and RAM upgrades) are a great place to stretch profit margins. A quick search of the Apple store for cables and adapters will turn up dozens of genuine Apple offerings ranging in price from $19 on up to $99. So, taken in context, the Thunderbolt cable is actually a mid-priced cable from Apple, not an expensive one. It also means that cheap unbranded alternatives could quite realistically be sold for around $15, ICs and all.
Regarding your HDMI cable experience, Category 1 or “Standard” HDMI cables are only rated for 1080i60, whereas Category 2 or “High Speed” cables will do 1080p60, 4K, 3D, Deep Color, etc. Older cables weren’t marked as such, and thus YMMV.
snakeInTheGrass - Friday, July 15, 2011 - link
Yeah, the SCSI cables were $75+ easily, you needed terminators, and do you remember the fine SCSI1/2/3 connector differences so you needed adapters or cables with different ends depending on the devices. I still have probably what WAS $500 of cables in my closed.Inflation adjusted, these $50 cables are about the equivalent of $15 cables back in those days, so frankly they don't sound too bad, especially considering the fact that it's industry leading performance right now.
As for comparing to Monster cables, these Thunderbolt cables have controllers built into them and presumably do have to meet tighter tolerances than USB, particularly as they carry 2 x 10Gbps data streams. But you're right that Monster cables are a rip off.
flowynn - Friday, July 8, 2011 - link
I remember those days well. My need for speed SCSI habit was insanely expensive.MonkeyPaw - Friday, July 8, 2011 - link
It reminds me of FB-DIMMs, an expensive solution that uses additional energy, and the components cost more than devices it replaces. Controllers in the cables AND on the motherboard and peripherals? Maybe the optical solution will make more sense.CrimsonFury - Monday, July 11, 2011 - link
I thought the initial copper cables didn't need any controllers in them? The impression I got from earlier articles was that Intel said their Thunderbolt implementation could scale to optical in future for greater speeds by releasing optical cables with a copper to optical controller in each end of the cable once controller costs had come down from mass production.MobiusStrip - Tuesday, July 12, 2011 - link
No, they need optical in the ports and wires.By reneging on the light in "Light Peak", Intel effectively killed it. Who knows why they're playing dumb in pretending that they're going to get the industry to adopt Thunderbolt and then turn around and adopt an optical solution right afterward. Just idiotic.
André - Friday, July 8, 2011 - link
I find it especially funny considering that all current Thunderbolt solutions (A/V equipment or storage enclosures) are all in excess of $999 to begin with.