I'll go to the Apple Store and see how much heat is coming off these things.
It's a moot point for me since I'd never buy an all-in-one anyway.
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Why upgrade to 4.0GHz and M295X?
- Thread starter mstgkillr
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It's a moot point for me since I'd never buy an all-in-one anyway.
OK, so someone answer me this PLEASE!
If I upgrade to the 4GHz i7 w/ HyperThreading, will I see a noticeable OVERALL performance increase? For example, opening Safari on my current 3.4GHz i5 takes a little bit with all the tabs I usually have open. At least there is now a healthy 500MHz difference between the two CPUs and not just 100-200.
And what about this TCON Apple "built by itself" to push all those pixels around?
If I upgrade to the 4GHz i7 w/ HyperThreading, will I see a noticeable OVERALL performance increase? For example, opening Safari on my current 3.4GHz i5 takes a little bit with all the tabs I usually have open. At least there is now a healthy 500MHz difference between the two CPUs and not just 100-200.
And what about this TCON Apple "built by itself" to push all those pixels around?
Nope, i7s only benefit in hyper threaded software like FCP X, Handbrake, etc.
Since I use these two heavily, I needed the i7 upgrade.
Touching the enclosure will not tell you anything scientific about the thermal performance of the iMac. It's like touching your engine to see if it's running at around 100 degrees Celsius, how it should, or at 120 degrees Celsius.
Yes, this is absolutely true. I had an i7 iMac for a while and pretty much the only time it ever used the hyperthreading was Handbrake transcoding. So it's not worth your money unless you know you will be using software which exploits it. Makes no difference to gaming.
To clarify this, there is no such thing as "hyper-threaded software". Rather there is only multi-threaded software. Any pool of threads can be scheduled on a hyperthreaded core by OS X.
A thread is an independent asynchronous flow of control within a process (ie app). Most apps are heavily multi-threaded, as can be seen from casual examination with Activity Monitor.
Just opening Safari produces about 24 threads. Each Safari tab spawns another process, each with its own threads. On my iMac opening 7-8 tabs produces a total of about 300 threads.
This does not automatically mean a hyper-threaded CPU will speed up Safari, since most of those threads are not in a runnable state, but waiting on I/O, or a synchronization event. However any app with multiple threads in a runnable state are potential candidates for hyper-threading.
The OS X thread dispatcher is hyper-thread aware and will often schedule a thread per physical core (rather than a thread per logical core) if it judges that more efficient. This can be seen in Activity Monitor when every other logical core is scheduled.
While there are no "hyper-threaded apps" per se, developers can use various techniques to make their apps better behave on a hyper-threaded CPU. Intel has guidelines on this: https://software.intel.com/en-us/ar...d-applications-a-platform-consistent-approach
Other contemporary non-Intel CPUs use hyper-threading aggressively, generally called SMT (Simultaneous Multi-Threading). E.g, both the Oracle Sparc M7 and IBM Power8 CPU can run 8 threads per CPU core.
The poster said: "opening Safari on my current 3.4GHz i5 takes a little bit with all the tabs I usually have open."
The 4Ghz retina iMac is clocked about 18% faster, plus the Instructions Per Clock will be a little better, plus if his i5 machine isn't SSD, he can get that. All of those things will produce a considerably faster user experience -- regardless of hyperthreading.
It's all a matter of chance. My 2006 24" iMac lasted until 2014, my 2011 Macbook Pro laster until.... 2014. So it really depends on the hardware. Frankly, the GPU is always the first thing that died on me in both cases so I can't really be all too happy with something that goes to 102 degrees Celsius (as shown in a youtube review).
anything "Scientific"? That's an odd way of putting it.
Please note, at no time did I say I was going to touch anything. Touching anything at 100C or 120C will still leave a nasty burn.
I believe empirical observation is encouraged by the scientific method, and I feel I'll have no problem determining whether or not the computer is capable of operating comfortably within thermal limits generally associated with electronic devices.
You said, "I'll go to the Apple Store and see how much heat is coming off these things". If we take that comment at face value, then my analogy is completely correct.
Unless I misunderstood how you're going to "see how much heat is coming off".
How will you determine this at the Apple Store?
Your analogy is not apt. There is no way I can "touch the engine" of an iMac in any circumstance without purchasing it, which I have no intention of doing.
The only external signs necessary to determine any issues would be the fan response to heavy, but normal GPU and CPU load over a reasonable period of time. Hopefully they'll have apps more taxing than a calendar.
I do possess an accurate infra-red thermometer, so I could compare vented air from this and other iMacs. That would, in fact, literally tell me "how much heat is coming off these things".
My analogy is completely apt. What information will you gleam from listening to the fan, other than deciding that it is working? Noisy fan, not so noisy fan. Sounds like pretty conclusive stuff to me.
Let's go back for a moment. What's the best way to check if your engine is overheating? You look at the temperature gauge. Checking how hot the air is coming out of the exhaust (although important for EGR), listening to the fan, or touching the engine is not going to give you anything conclusive. Without looking at the temperature gauges on the iMac, you won't be able to decide much.
Checking the temperature of the vented air, whilst important, isn't going to tell us if the iMac is throttling and what temperatures the components are running at. You left out the most important and conclusive test of all, often cited on these forums, touch the back of the iMac. If it's hot, then the iMac must be overheating and rubbish.
What would be interesting is to put a load on the latest iMac and then check how turbo boost is doing and whether the CPU is throttling itself. This is something one could do at the store.
Code:
pmset -g thermlog
Note: No thermal warning level has been recorded
2014-10-25 22:58:28 +0100 CPU Power notify
CPU_Scheduler_Limit = 100
CPU_Available_CPUs = 8
CPU_Speed_Limit = 100The same test to check what the GPU is doing would also be wonderful, but I see no way of doing that at the apple store.
But do carry on.
The clock was running down to return my newly purchased late 2013 refurbished i7 iMac. I was questioning my need for a retina display but based on the positive early reports and the modest additional cost for the retina, I decided to return my 2013 unit while I could and splurge on the riMac.
I upgraded to the 4.0 GHz i7 for raw processing power and hyper threading ability (I do 2d photo editing with software that uses hyper treading) and the 295GPU because my Apple rep recommended it if I plan on keeping the machine for a long time (I do). I also got the 1TB SSD because I can fit all my files on it for now...and it's the most elegant, if expensive, solution. I'm completely confident this Mac will easily keep me a happy man for 5 years...which is 2-years much longer than I've ever kept a PC, so the cost seem worth it to me.
I upgraded to the 4.0 GHz i7 for raw processing power and hyper threading ability (I do 2d photo editing with software that uses hyper treading) and the 295GPU because my Apple rep recommended it if I plan on keeping the machine for a long time (I do). I also got the 1TB SSD because I can fit all my files on it for now...and it's the most elegant, if expensive, solution. I'm completely confident this Mac will easily keep me a happy man for 5 years...which is 2-years much longer than I've ever kept a PC, so the cost seem worth it to me.
Well, I can state with some degree of certainty, that any Mac I've ever owned, when under a heavy GPU or CPU load has generated significant fan noise, which cannot be confused with normal fan functioning.
You'll be saddened to see that many new cars are no longer coming with temperature gauges.
Checking the temperature of the vented air, whilst important, isn't going to tell us if the iMac is throttling and what temperatures the components are running at. You left out the most important and conclusive test of all, often cited on these forums, touch the back of the iMac. If it's hot, then the iMac must be overheating and rubbish.
If it's hot, does that mean it's overheating, or just effectively dissipating heat?
Well, since that test is unavailable, I'm just going to listen to the fan under a heavy GPU load if you don't mind. I'm not really that concerned about the CPU, and since I'm not buying one anyway, it will merely be a source of amusement.
Maybe. I could see them waiting until 2016 since the Retina might have bought them more time and they might be releasing a 21" retina next year.
johnnyturbouk
macrumors 68000
Same here, but i am seriously wooed by the 5kimac and very impressed - i wll mostly wait until the skylake rendition, but this is a marvel of a machine apple have released, truly innovative.
If mine slips and I call and complain I wonder if they'll wave the expedited shipping fee. I doubt it, but right now I'm expected to get my iMac on the 6th.
It is, but it doesn't suit my needs, so I'll depend on others to investigate.
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Well, when you run your throttling test, let me know how the fan sounds.