Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Fastball32

macrumors member
Original poster
Nov 17, 2011
97
43
Hi,

I've been a long time reader of these forums and finally decided to register so I can report this significant finding.

First off, I've had several Cinema Displays in the past, including a 23" and a 24". Last year, I bought two 27" LED Cinema Displays to hook up to my 2010 Mac Pro and love them.
I've grown impatient with waiting for the new Mac Pro's and decided to slowly convert to the new Thunderbolt ecosystem, with hopes that Apple will make Thunderbolt compatible with new Mac Pros (if they are refreshed). I've recently sold one of my 27" Cinema Displays and with that money I purchased a brand new Thunderbolt Display.
So currently I have one 27" LED Display hooked up to my Mac Pro and one Thunderbolt Display hooked up to my 2011 MacBook Air.

Since I've only had experience with this one Thunderbolt Display, this is by no means a scientific test, but I have noticed a couple differences in the 2 days I had with the Thunderbolt Display.

- MacBook Air fans spin VERY loudly when watching videos on YouTube. I have never noticed the fans spin when it was hooked up to my LED Display (via USB and mini displayport). I have switched the MacBook between the 2 displays a few times, and after about 5 minutes, the fans will always be audible when it is connected via Thunderbolt.

- The max brightness appears to be much brighter on my LED Display vs the Thunderbolt Display. I have no way of measuring this officially, but my eyes begin to strain when I max out the brightness on my LED display, which is a good thing because the ability to be bright is always welcome (whereas on my Thunderbolt Display, my eyes do not strain).

Hopefully, Apple can release firmware updates to address the fan issue, but if Thunderbolt is associated with more energy transfer and thus heat, then fans do need to spin fast to protect the computer. The spinning fans make me wonder if the CPU, Ram, SSD will prematurely wear out when connected to the Thunderbolt Display (due to heat), also, is there unnecessary information being transferred through Thunderbolt to generate the extra heat?
The lower max brightness is concerning, is Apple using cheaper parts now? It was my understanding that the LED panel should be the same, so I'm not sure why I'm noticing this or if it is just my unit.

Please don't let me deter you from buying a Thunderbolt display, because it is very nice. Overall, you are not likely to notice the brightness issue unless you have both next to each other, but the fans are definitely noticeable and at this point, I'd rather hook up my MBA to my Cinema Display so the fans won't kick up.

Hoping for some feedback or similar experiences.
 
I've got the cinema version with a mba and a client has the same setup but with the thunderbolt display. Neither have any fan speed issues.

As everyone else has already said, make sure you have the display firmware and thunderbolt updates installed.
 
To compare max brightness, they both need to be new. All backlights have a half life. Say they have a half life of two years when run at 100% brightness. That would mean after four years it will only achieve 25% of the original brightness, therefore max brightness is a moving target. When they're new, I suggest turning it down to a comfortable place for your eyes. As the display ages, you can inch it up to maintain a relatively consistent brightness. Typically you want brighter displays in a brighter work area, but white backgrounds should still be comfortable on your eyes.

The stuff about brightness applies to any and all computer displays. This is just how backlights fade, which is why I don't tend to suggest maximum brightness when it's new. They're made to be bright initially so that they won't appear dark after a year.
 
To compare max brightness, they both need to be new. All backlights have a half life. Say they have a half life of two years when run at 100% brightness. That would mean after four years it will only achieve 25% of the original brightness, therefore max brightness is a moving target. When they're new, I suggest turning it down to a comfortable place for your eyes. As the display ages, you can inch it up to maintain a relatively consistent brightness. Typically you want brighter displays in a brighter work area, but white backgrounds should still be comfortable on your eyes.

The stuff about brightness applies to any and all computer displays. This is just how backlights fade, which is why I don't tend to suggest maximum brightness when it's new. They're made to be bright initially so that they won't appear dark after a year.

How would that make sense when the OP stated that the ACD (older display) is brighter than the TBD (newer display) when both turned up at max brightness?
 
Thanks for the replies.

Thekev- point well taken, which was why I was disappointed about my new thunderbolt display appears duller than my one year old cinema display.

The brightness disparities are not a big deal, since I usually never put it more than 50% brightness.

The louder fans is what I'm worried about. I definitely have the latest firmware on my laptop and Apple released updated Thunderbolt display firmwares in the past week, which I have updated.

The MBA fans are definitely audible, borderline loud (like the reviews for the Thunderbolt Little Big Disk from Lacie).
Here's an excerpt from a MacWorld article that may shed some light.

http://www.macworld.com/article/163677/2011/11/how_to_connect_to_thunderbolt.html
One thing we haven't seen yet is a bus-powered Thunderbolt peripheral. Of course, we wouldn't expect a six-drive RAID like the Promise Pegasus R6 to operate under bus-power. However, LaCie offer the Little Big Disk with a quad interface (it can connect to USB 2.0, FireWire 800, FireWire 400 via FireWire 800 adapter, and eSATSA), a drive similar to the Little Big Disk with Thunderbolt. The quad interface laCie drive can run on the power provided by FireWire, while the Thunderbolt version can't. Thunderbolt does provide 10 watts of power, but the cable itself uses a significant portion of that power, and if you were to daisy chain other peripherals off of the LaCie, it may not provide enough power to spin up the drives.

So basically, it says the Thunderbolt Cable itself uses a significant portion of the 10 Watts of power. Maybe this is what is causing extra heat???

From the responses so far (concerning fan noise), I may be in the minority. But if I didn't have both Cinema and Thunderbolt Displays, I probably wouldn't have noticed the difference.
 
How would that make sense when the OP stated that the ACD (older display) is brighter than the TBD (newer display) when both turned up at max brightness?

Sample variation, different backlight design, etc. If the OP has the right software and a colorimeter device he could obtain an approximation of the maximum brightness level of the newer display and compare that to the stated specs. They will all get darker over time, but if the OP feels this is significantly off for a new display, he should take it to an Apple store now. Currently the stated max brightness is 375 cd/m2 for the LED and thunderbolt displays which is quite bright. I keep mine set closer to 90, but the displays I'm using are designed to hold their contrast at a lower luminance level.
 
My new Thunderbolt Display is not defective in anyway, I'm just saying that my LED Cinema display (which is rarely used), appears to have a brighter max brightness. Since the max brightness is theoretically 375 cd/m2, you would expect slight variations to be slightly below this value.

My MacBook Air is continuing to blow its fans noticeably after watching about 10 min of HD Youtube videos when connected to the Thunderbolt Display - but remains quiet when connected to my Cinema Display.
 
My MacBook Air is continuing to blow its fans noticeably after watching about 10 min of HD Youtube videos when connected to the Thunderbolt Display - but remains quiet when connected to my Cinema Display.

I'm having the same issue with extreme fan RPM and the side effect of noise. I'm finding it totally unacceptable since in my case I have nothing running. With 99.2% idle CPU the fans are at what sounds to be their maximum (much, much louder than I've ever heard them before). I too have the latest firmware updates and such. I'm wondering if it is related to a specific model of the MBA? I have a 13.3" i7 256. Do you have the same model?

In any case, I do hope a firmware update addresses this as thermal issues degrade silicon components considerably. For example, I worked for a major OEM as a portables engineer, and we ran machines through a "torture chamber" to simulate accelerated usage. We found excessive heat to cause degradation by as much as 33-40% faster(based upon fallout percentage and MTBF). I don't claim to know Apple's statistics But I would expect them to be similar (note that the MTBF differs greatly by component but typically greater than 100,000 hours (could be as long as 1x10^6... So I wouldn't expect to see any serious issues but the fans will wear out quicker. And as they do, they may allow areas of the logic board to overheat, thus causing issues.

Right now though the CPU is running hot, which causes performance degradations. In fact I just GeekBench'd my MBA and it only scored 5118, whereas it normally scores 5885 when not connected to the Thunderbolt Display.
 
I'm having the same issue with extreme fan RPM and the side effect of noise. I'm finding it totally unacceptable since in my case I have nothing running. With 99.2% idle CPU the fans are at what sounds to be their maximum (much, much louder than I've ever heard them before). I too have the latest firmware updates and such. I'm wondering if it is related to a specific model of the MBA? I have a 13.3" i7 256. Do you have the same model?

My MacBook Air is an 11" model with the i7 1.8ghz processor and 256GB SSD, which I bought brand new directly from Apple.
My Air is usually silent and cool to touch even after long hours of use on it, but after a short time connected to my Thunderbolt Display (TB display has no other connections), it runs loud and warm to touch. The fans stay audible until I idle it for long periods or I put the computer to sleep.
The fans are so loud in fact, I like Ravenlynch have concerns that this is definitely not good for the computer.
From the previous posts, maybe this is limited to the i7 MBA's, but the fact that I have no problems when it is connected to my 27" Cinema Display makes me think this is a Thunderbolt problem.
 
My Air is usually silent and cool to touch even after long hours of use on it, but after a short time connected to my Thunderbolt Display (TB display has no other connections), it runs loud and warm to touch. The fans stay audible until I idle it for long periods or I put the computer to sleep.

Perhaps the Thunderbolt circuitry is idle when the display is not connected, consuming little or no power.

When connected to the display, the Thunderbolt circuitry inside the Macbook Air is active, consuming more power. More power = more heat.

For my Macbook Air 13" w/i7 and 256GB SSD, it is normally silent. The other day, I was converting some videos using Handbrake; no display or Thunderbolt peripherals attached. After a few minutes the fan started and continued for the rest of the conversion (about 30 minutes). The fan remained on for a few minutes after the conversion completed.

This indicates to me:
- video conversion taxes the processor more
- more heat is produced due to taxed processor
- fan is temp controlled, and remains on until components reach acceptable, cooler temperature.

I'll rerun tests with my LBD when I get a chance.
 
the fact that I have no problems when it is connected to my 27" Cinema Display makes me think this is a Thunderbolt problem.
It appears at least to me to not be a thunderbolt problem per se, but rather a video acceleration problem, or, lack of the same rather. For whatever reason, flash video seems to run entirely in software decoding mode, causing very high CPU useage and thus a lot of heat that needs to be cooled off with the fan.

On the other hand, watching DVDs, does not load the processor noticeably, and the fan remains pretty much silent...

Presumably, OSX may need a video driver update to make sure that hardware acceleration doesn't get disabled when a thunderbolt screen is connected.
 
Presumably, OSX may need a video driver update to make sure that hardware acceleration doesn't get disabled when a thunderbolt screen is connected.

Excellent point. After some more observations, when I play HTML video (like the ones on iTunes Univ) the fans don't kick up, just Flash sites like YouTube.

Another consideration is that when I remove the Thunderbolt cable on my MacBook Air, it is warm to touch whereas the USB & MagSafe adapter do not get hot. The mini-displayport on the LED Cinema display never got hot, so I'm pretty sure that Thunderbolt is generating heat because it is not optimized yet.
 
Hi,

I've been a long time reader of these forums and finally decided to register so I can report this significant finding.

First off, I've had several Cinema Displays in the past, including a 23" and a 24". Last year, I bought two 27" LED Cinema Displays to hook up to my 2010 Mac Pro and love them.
I've grown impatient with waiting for the new Mac Pro's and decided to slowly convert to the new Thunderbolt ecosystem, with hopes that Apple will make Thunderbolt compatible with new Mac Pros (if they are refreshed). I've recently sold one of my 27" Cinema Displays and with that money I purchased a brand new Thunderbolt Display.
So currently I have one 27" LED Display hooked up to my Mac Pro and one Thunderbolt Display hooked up to my 2011 MacBook Air.

Since I've only had experience with this one Thunderbolt Display, this is by no means a scientific test, but I have noticed a couple differences in the 2 days I had with the Thunderbolt Display.

- MacBook Air fans spin VERY loudly when watching videos on YouTube. I have never noticed the fans spin when it was hooked up to my LED Display (via USB and mini displayport). I have switched the MacBook between the 2 displays a few times, and after about 5 minutes, the fans will always be audible when it is connected via Thunderbolt.

- The max brightness appears to be much brighter on my LED Display vs the Thunderbolt Display. I have no way of measuring this officially, but my eyes begin to strain when I max out the brightness on my LED display, which is a good thing because the ability to be bright is always welcome (whereas on my Thunderbolt Display, my eyes do not strain).

Hopefully, Apple can release firmware updates to address the fan issue, but if Thunderbolt is associated with more energy transfer and thus heat, then fans do need to spin fast to protect the computer. The spinning fans make me wonder if the CPU, Ram, SSD will prematurely wear out when connected to the Thunderbolt Display (due to heat), also, is there unnecessary information being transferred through Thunderbolt to generate the extra heat?
The lower max brightness is concerning, is Apple using cheaper parts now? It was my understanding that the LED panel should be the same, so I'm not sure why I'm noticing this or if it is just my unit.

Please don't let me deter you from buying a Thunderbolt display, because it is very nice. Overall, you are not likely to notice the brightness issue unless you have both next to each other, but the fans are definitely noticeable and at this point, I'd rather hook up my MBA to my Cinema Display so the fans won't kick up.

Hoping for some feedback or similar experiences.


It is a very difficult decision.
 
I am running the Thunderbolt Display on the i7 Air, and I've not seen the problems you mentioned. I use it 10-12 hours a day and rarely have a fan come on. I'm running it pretty loaded... virtual machines, photoshop, lightroom, lotus notes, ms office, multiple browsers, etc.. I will occasionally hear a fan when doing video work, but that is not unexpected, and would happen whether the TBD is attached or not. So I suspect there may be something wrong with either your Air or your TBD if you are thinking your fan is running so badly that it will prematurely kill your Air. That's not at all consistent with my experience.

As for the brightness comment, there is no way you should be ever running your display at max brightness. My office is in front of a huge picture window, so well lit... and I have always calibrated my displays. They are nowhere near max on brightness. I just sold my 4 year old Dell 30" display which I loved and which had performed flawlessly (always calibrated with a Spyder2), and the buyer called to complain that it was making buzzing noises and wouldn't go as bright as his old one. He was testing it with the brightness at max. Its kind of like taking your car out on the highway and testing it with the accelerator to the floor. That's not a normal use case for a car, and its not a normal use case for a display. Perhaps the max brightness is somehow contributing to the Air fans you are experiencing??? That doesn't seem technically feasible, but wouldn't rule it out.

All the detailed independent reviews of the Thunderbolt vs. Cinema have reported that from a display perspective they are identical. I suppose its possible the thunderbolt interface is loading in some way, but I've not seen it. I'm using it for GigaE constantly, as well as FW800 and a ton of USB stuff. No fans.
 
I am running the Thunderbolt Display on the i7 Air, and I've not seen the problems you mentioned. I use it 10-12 hours a day and rarely have a fan come on.

As for the brightness comment, there is no way you should be ever running your display at max brightness.

At night, I always have the brightness at 1-2 bars, during the day it is still well under the 50%, and closer to 25%. I only put up the brightness for testing purposes.
The brightness issue is entirely subjective on my part and I realize there are slight differences between displays even in the same model, so I am not too concerned with the brightness issue.

As someone who has had extensive use with MacBooks and previous Cinema Displays, the Thunderbolt cable is ALWAYS warm when I disconnect the MacBook Air. I don't do too many processor intensive things, mainly surf the web. Flash seems to be the biggest culprit for the fans. I don't think there is anything wrong with my MacBook and I certainly wouldn't trouble Apple to return this thing because it functions beautifully. The Thunderbolt Display is also very nice, I guess I just wanted to see if anyone else noticed what I have. Also makes me wonder if I should get AppleCare on my MBA. I appreciate all the responses, even if the responses are contradictory to my experiences.
 
At night, I always have the brightness at 1-2 bars, during the day it is still well under the 50%, and closer to 25%. I only put up the brightness for testing purposes.
The brightness issue is entirely subjective on my part and I realize there are slight differences between displays even in the same model, so I am not too concerned with the brightness issue.

That range makes sense. Those displays are very very bright especially when new. I intentionally purchase ones that can be set lower because anything that bright makes my eyes hurt :(.

I really don't know why a newer one would be dimmer. There are some panel blocking methods that can be used to improve uniformity from center to edge, but I've never heard of Apple implementing something like that (it's expensive to do so they would mention it as a feature). That is one thing that would cause a display to look dimmer because it brings down the brightest spots on the panel. Bleh... I looked for data on this and I can't find anything similar.
 
Why would you test a display at max intensity when it will never be used in that state? Again, do you test drive a car by running it wide open down a highway, when you will never drive it that fast in its life of use? I can see maybe testing it 10% over normal intensity.

As for the cable being warm, I don't think that's necessarily indicative of any problem. The cable is tiny and has a lot of stuff going on. For point of reference, I haven't ever noticed mine being warm.

You've described an experience you are having that is different from your own prior experience, and what others are experiencing, yet you continue to say you don't think there is anything wrong with your MBA or display? I don't understand that logic.
 
One last comment on the "which one wins" thought. Apple currently sells the Cinema and Thunderbolt displays for the same price. All independent comparison reviews done by the reputable review sites have concluded that the video performance of the two are nearly identical. The TBD includes a thunderbolt hub which the ACD does not. I'm guessing that when Belkin finally ships their hub in 2012, that it will likely sell for $150-200 initially. So the Apple includes a $200 hub with the same internal display, and further integrates it so you only have one cable to connect for all that function.... for the same price. Seems like the TBD wins this handily.
 
Why would you test a display at max intensity when it will never be used in that state? Again, do you test drive a car by running it wide open down a highway, when you will never drive it that fast in its life of use? I can see maybe testing it 10% over normal intensity.

I don't understand that logic.

Although most people would never test their fast cars by driving at its top speed, most people would accelerate 0-60 or 1/4 mile to its potential, at least once for testing purposes. Car enthusiasts actually recommend throttling the engine at times, to keep peak performance because race car engines were made to do so.
I never use my display at max brightness, I just maxed it for about a minute to see the potential of the display and then lower it again when I actually use the monitor, I don't think this is unusual.

You've eluded that I am the only one that is experiencing the same problem, but there is another poster on this thread, and a couple of others scattered in different threads (mac mini) that have experienced similar issues of loud fans.

I have both displays, so I am not biased in saying that the Cinema display is much more optimized at this point. Apple has already released a few Thunderbolt firmware patches and I suspect more will come in the near future.

Obviously the Thunderbolt Display has better ports and more importantly, an HD Facetime camera. However, if a buyer wants to have the latest and greatest all the time, then the Thunderbolt Display will be dated next fall, when Apple could easily incorporate USB 3.0 (which Ivy Bridge is expected to have), also the HD Facetime cam could be upgraded to 1080p, at 720p although nicer than isight, is not that much better in my opinion over the isight cam.

Issues to remember with Thunderbolt, if you were to Bootcamp, Windows drivers for Thunderbolt displays are not optimized, so using eyefinity would likely not be smooth if it works in the first place. Also, Thunderbolt can transmit 10 watts of power, yet it still cannot power the Little Big Disk (not even the SSD version), and requires an external power source, yet there are many bus-powered USB and Firewire drives. The Thunderbolt connection is also longer than the mini-displayport connection, yet this is a good trade for not having to hook up another USB connection. Since Thunderbolt transmits both mini-display and pci, I wonder if 10 watts of power are continuously being transmitted, even for just display purposes (although pci info is being transmitted if you use the display speakers)...

I appreciate your comments, I can see your point of view that i would have a faulty MBA or Thunderbolt Display, especially if you are not experiencing or noticing any loud fans or warm thunderbolt connection on your setup. The warm thunderbolt connection is similar to touching an AC adapter after using it for a period, not hot but warm.
 
Finally posting a picture I took in the dark. On the left is the thunderbolt display hooked up to my MBA, the right is my cinema display hooked to a mac pro, both at 100% brightness for the pic. It's hard to tell on the picture, but it seems the one on the right is slightly brighter, but both are nice. Also maybe it's me, but does the one on the right seems to have a warmer hue? Both are calibrated using the Apple Display calibration in OS X.

What are your guys' thoughts?

FYI, Apple currently has Refurbished Thunderbolt Displays on its website for $850, this is the first time I've noticed it being available. At that price point, the choice of Thunderbolt over the Cinema Display makes it easier (unless your a Mac Pro person).
 

Attachments

  • acd.JPG
    acd.JPG
    809.1 KB · Views: 1,265
Another consideration is that when I remove the Thunderbolt cable on my MacBook Air, it is warm to touch whereas the USB & MagSafe adapter do not get hot.
That's because the TB cable connector contains a signal transciever chip that compensates for the attenuation of the copper cable itself. This is necessary because TB runs at 10 gigabits per second bidirectionally per datalink, and without that chip there would be far too many transmission errors for this high data transfer speed to be feasible. That the connector becomes slightly warm is not anything you should be concerned with however; it is normal and harmless.

Getting Applecare is a nice safety precaution. You may not need it, but if you do then you're covered. :)

I am running the Thunderbolt Display on the i7 Air, and I've not seen the problems you mentioned. I use it 10-12 hours a day and rarely have a fan come on. I'm running it pretty loaded... virtual machines, photoshop, lightroom, lotus notes, ms office, multiple browsers, etc..
The issue is specifically with flash video, so unless you test with that, you won't be seeing this behavior of course. That's pretty self-evident, wouldn't you say? ;)

Also, no, the brightness of the display won't affect the speed of the fan in the Macbook connected to it. It will of course affect the speed of the fan in the display itself though; the TBD burns a lot of power at max brightness - and I assume the same is true for its ACD predecessor as well.
 
Also maybe it's me, but does the one on the right seems to have a warmer hue? Both are calibrated using the Apple Display calibration in OS X.

What are your guys' thoughts?
You can't expect to get accurate results using your eyes and OS X calibration tool. You will need to use hardware-based solution such as XRite or Spyder. I've calibrated mine using XRite i1Display Pro and I would say the hue is on par with other displays that I use.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.