Unlock 8 Virtual Cores on rMBP

[yusukeaoki]

LOL 🙄
Who told you that unlocking the CPU was "recommended"
If that is your friend, I would not talk to him.

 

[Freyqq]

It has 4 physical cores and 4 virtual cores = 8 cores. That's it. There's no other cores to unlock.

 

[Squilly]

Maybe I was mistaken. Told to stress the cores? I dunno, saw it on Apple Support web site.

 

[mrapplegate]

Maybe I was mistaken. Told to stress the cores? I dunno, saw it on Apple Support web site.

Nope. Your friend was wrong or he is joking. No need to "stress the cores".

 

[tninety]

What are you guys smoking tonight?

 

[Ploki]

Image

IT JUST KEEPS GOING ON.

Maybe I was mistaken. Told to stress the cores? I dunno, saw it on Apple Support web site.

You don't need to do that. I very much doubt it was on Apple Support pages.

 

[Erasmus]

Why is this thread still full of arguing and smart-arsery?

I'm sure your friend suggested you fully load all CPU cores, most likely to test your maximum temperatures.

The two methods of doing this that I would recommend is either downloading Handbrake, and converting a HD video with it (I know this can fully load 8 virtual cores), or opening 8 terminal windows, and typing "yes > /dev/null" in each.

Download iStat Pro, load your CPU to 800%, and watch the CPU temperatures and fan speeds. If your CPU temperature stays under 100˚C, you are fine.

EDIT: This will NOT damage your computer. If it does, it was faulty to begin with.

 

[Squilly]

Why is this thread still full of arguing and smart-arsery?

I'm sure your friend suggested you fully load all CPU cores, most likely to test your maximum temperatures.

The two methods of doing this that I would recommend is either downloading Handbrake, and converting a HD video with it (I know this can fully load 8 virtual cores), or opening 8 terminal windows, and typing "yes > /dev/null" in each.

Download iStat Pro, load your CPU to 800%, and watch the CPU temperatures and fan speeds. If your CPU temperature stays under 100˚C, you are fine.

EDIT: This will NOT damage your computer. If it does, it was faulty to begin with.

I downloaded iStat Pro but dunno how to change settings/load. Umm... how? Nevermind. Just opened Photoshop, Illustrator, C4D, and 11 chess games. Everything seems okay.

 

[yusukeaoki]

I downloaded iStat Pro but dunno how to change settings/load. Umm... how? Nevermind. Just opened Photoshop, Illustrator, C4D, and 11 chess games. Everything seems okay.

Thats nothing...
And if the CPU needs more power, they automatically go into turboboost mode.

 

[Squilly]

Thats nothing...
And if the CPU needs more power, they automatically go into turboboost mode.

It's possible to stress the CPU over 100%?

 

[yusukeaoki]

It's possible to stress the CPU over 100%?

What do you mean you want to stress it over 100%?

If thats what you mean, try opening all of CS6 apps and render tons of video FCPX.
Run some games while you're at it.

 

[Squilly]

What do you mean you want to stress it over 100%?

If thats what you mean, try opening all of CS6 apps and render tons of video FCPX.
Run some games while you're at it.

"Download iStat Pro, load your CPU to 800%, and watch the CPU temperatures and fan speeds. If your CPU temperature stays under 100˚C, you are fine."

 

[Erasmus]

"Download iStat Pro, load your CPU to 800%, and watch the CPU temperatures and fan speeds. If your CPU temperature stays under 100˚C, you are fine."

Firstly, Turbo Boost is completely invisible in OSX. It happens, but there is no way of seeing it. The clock speed can increase by as much as 50%, but full load is still 100%/800%.

I said 800% because some methods of calculating how much CPU is being used do it per virtual core, and others do not. For example, iStat Pro's "CPU" panel shows the percentage of all 8 virtual cores combined that are used, and therefore tops out at 100%. If you enable the "Processes" panel (somewhere in its options) it lists each process activity per virtual core, therefore tops out at 800%. It's the same thing, whether it's 8 chess processes at 100% each, or 1 Handbrake encode process at 800%.

So in summary, (based on that previous pic) you have now stress tested your machine, and your temps look fine.

 

[yusukeaoki]

"Download iStat Pro, load your CPU to 800%, and watch the CPU temperatures and fan speeds. If your CPU temperature stays under 100˚C, you are fine."

Said above me as well but if you are encoding a vid and check activity monitor, it will probably be over 100% as well.
Unless you have windows on there, it is impossible to see if TurboBoost has engaged or not.

 

[duervo]

Said above me as well but if you are encoding a vid and check activity monitor, it will probably be over 100% as well.
Unless you have windows on there, it is impossible to see if TurboBoost has engaged or not.

The best you'll be able to get is by using the Intel Power Gadget. It displays Power Usage and CPU Frequency stats. If you know the TurboBoost value of your CPU, you can find out if it's been engaged by monitoring the frequency with the tool.

http://software.intel.com/en-us/articles/intel-power-gadget/

 

[Valkyre]

This thread is confusing as hell...

rmbp has 8 cores?? I thought a quad core means 4 cores and 8 threads...

what is all this thing about 8 cores?

 

[Puevlo]

CPUs are just like muscles. If you don't use them they undergo atrophy. Stress them often.

 

[sammich]

Couldn't you do that dev > null terminal command 8 times to max out the CPU?

yes > /dev/null &

run that a few times

 

[Erasmus]

This thread is confusing as hell...

rmbp has 8 cores?? I thought a quad core means 4 cores and 8 threads...

what is all this thing about 8 cores?

A thread is a piece of software code that is executed by the CPU. It has nothing to do with hardware. A single CPU core normally can run one thread at a time.

Hyperthreading allows a single CPU core to often act as if it is running two threads simultaneously, via a little extra funky hardware. It therefore appears to software to be two cores; even though really, it's only one.

This means that as far as hardware is concerned, the 15" MBPs have a 4 core CPU. As far as software running on it is concerned, it has an 8 core CPU. And depending on how that software is threaded, the performance of the CPU can be anywhere between that of a single core, and 8 cores.

As a related note, TurboBoost is designed to allow the CPU to overclock one core by as much as 50% by idling the other 3 (real cores matter here) for running poorly threaded software faster than it would otherwise. Its second objective is to allow the entire 4 core CPU to overclock by a much lower margin, in order to dynamically push the performance of the CPU to the limits of the computer's thermal management system (the fans and heat sinks).

 

[Erasmus]

The best you'll be able to get is by using the Intel Power Gadget. It displays Power Usage and CPU Frequency stats. If you know the TurboBoost value of your CPU, you can find out if it's been engaged by monitoring the frequency with the tool.

http://software.intel.com/en-us/articles/intel-power-gadget/

Thanks for linking this, I didn't know it existed!

Apparently my quad 2.2GHz CPU idles at 800MHz, runs 2 processes at 3GHz, runs 4 processes at 2.7GHz, and runs at full load (8 yes-dev-null processes) at 2.5GHz.

A few hundred MHz lower than the maximum TB levels, but still a nice, totally automatic overclock 🙂
I would be very interested to see how the new rMBPs fare.

 

[Ploki]

Thanks for linking this, I didn't know it existed!

Apparently my quad 2.2GHz CPU idles at 800MHz, runs 2 processes at 3GHz, runs 4 processes at 2.7GHz, and runs at full load (8 yes-dev-null processes) at 2.5GHz.

A few hundred MHz lower than the maximum TB levels, but still a nice, totally automatic overclock 🙂
I would be very interested to see how the new rMBPs fare.

Quad 2.7:
idles @1.20ghz.
1 @3.6 (should be 3.7 i believe)
2 @3.5
4 @3.5
8 @3.3

 

[Ledgem]

What your friend most likely was talking about was CPU burn-in. This only applied to building your own computer. You would install the processor, apply thermal paste to the heat sink, then seat the heat sink to the processor, and run the processor at full load for a few hours to a day; the theory behind burning in was that the heat would help the thermal paste to settle, spread, and bond perfectly, which would result in the absolute optimum transfer of heat from the CPU to the heat sink.

There's some debate about whether burn-in was ever warranted, especially with modern thermal paste. Suffice it to say, burn-in doesn't apply to us (unless you're servicing your own Macbook Pro and are changing out the heat sink).

TL;DR: you don't need to stress your CPU.

It's possible to stress the CPU over 100%?

Depending on what program you're using to monitor core usage, yes. Some programs view each core separately, and add the percentages; maxing out one core is 100%, maxing out two cores is 200%, and so on.

This thread is confusing as hell...

rmbp has 8 cores?? I thought a quad core means 4 cores and 8 threads...

what is all this thing about 8 cores?

The retina MBP (and some MBPs before it) has four physical cores, but with Intel's hyperthreading technology, each core is recognized as having two logical cores (making for eight in total). As a very gross simplification, hyperthreading doubles up the instructions per CPU core. If you use software that states how many cores are available on the system (as certain 3D render suites do), you would see eight cores listed. This is also why the Activity Monitor shows eight graphs if you double-click on the CPU usage graph.

A quad-core processor with hyperthreading would lose out to a true octo-core processor; however, according to benchmarks a quad-core processor with hyperthreading will have around 25% better performance compared with a quad-core system without hyperthreading.