Unlock 8 Virtual Cores on rMBP

Squilly · Feb 4, 2013, 08:25 PM

I was told there was a way to unlock all cores on a rMBP by starting 8 chess games with computer vs computer. The problem: I can only start one. How do you start multiple games?

alphaod · Feb 4, 2013, 08:27 PM

What do you mean "unlock" cores?

It's just a computer. It comes working with 8 logical processors.

simsaladimbamba · Feb 4, 2013, 08:30 PM

Why do you want to do what?

Your Mac has one CPU with four real cores, each core having two virtual cores, giving you eight virtual cores as a whole, and if an application is written to take advantage of those, it will use them if it needs to. No need to "unlock" something.

And how many threads is that today? 10?

duervo · Feb 4, 2013, 08:33 PM

OS X does not support CPU affinity for individual processes. AFAIK, the kernel handles the distribution of processes amongst a CPU's cores. There is no way that I know of to force a process to run on a specific CPU core.

thejadedmonkey · Feb 4, 2013, 08:39 PM

Quote:

Originally Posted by duervo

OS X does not support CPU affinity for individual processes. AFAIK, the kernel handles the distribution of processes amongst a CPU's cores. There is no way that I know of to force a process to run on a specific CPU core.

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

Patrick Boyle · Feb 4, 2013, 08:43 PM

What are you guys smoking tonight?

Squilly · Feb 4, 2013, 08:44 PM

Just to stress the computer, see what it can do, that's all. I was told by someone that it's recommended.

chrise2 · Feb 4, 2013, 08:44 PM

Ask it to play global thermal nuclear warfare. It will unlock all 1024 cores.

simsaladimbamba · Feb 4, 2013, 08:48 PM

Quote:

Originally Posted by Squilly

Just to stress the computer, see what it can do, that's all. I was told by someone that it's recommended.

Then run benchmarks like Cinebench (nice visual thing), Xbench or GeekBench or some others. Or install HandBrake and convert some already ripped DVDs.

Asuriyan · Feb 4, 2013, 08:51 PM

I think someone was pulling your leg.

Squilly · Feb 4, 2013, 08:55 PM

Quote:

Originally Posted by chrise2

Ask it to play global thermal nuclear warfare. It will unlock all 1024 cores.

I'm on it. Don't get it at all though.

duervo · Feb 4, 2013, 08:59 PM

Quote:

Originally Posted by thejadedmonkey

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

You could, but that doesn't guarantee that each one will be pinned to a separate core.

OS X provides no method for CPU affinity. Running a process 8 times is no guarantee that each instance will get its own CPU core for its life ... It probably will, but no guarantees. For example. a scheduled process could start that could temporarily move one of those 8 instances to a core already in use by one of its siblings.

CPU affinity lets you tie a process to a single core for its entire life.

Windows NT (and newer can do it per process), as can Linux (for the past 7 or 8 years or so).

OS X doesn't ... at least anywhere I could find in any if the docs on darwin. Leaving such work up to the kernel CPU scheduler itself. Trust in the kernel, in other words.

Nermal · Feb 4, 2013, 09:02 PM

Quote:

Originally Posted by Squilly

The problem: I can only start one. How do you start multiple games?

You need to duplicate (Cmd-D) Chess.app.

Squilly · Feb 4, 2013, 09:11 PM

Quote:

Originally Posted by Nermal

You need to duplicate (Cmd-D) Chess.app.

Doesn't work. Press cmd+D in the app?

simsaladimbamba · Feb 4, 2013, 09:15 PM

Quote:

Originally Posted by Squilly

Doesn't work. Press cmd+D in the app?

Go to the Applications folder, select Chess.app and then press CMD+D, as CMD+D is a Finder keyboard shortcut for "duplicating" files and folders.

Also know, that you can use an avatar now.

Squilly · Feb 4, 2013, 09:28 PM

Quote:

Originally Posted by simsaladimbamba

Go to the Applications folder, select Chess.app and then press CMD+D, as CMD+D is a Finder keyboard shortcut for "duplicating" files and folders.

Also know, that you can use an avatar now.

Dually noted and yay! Thanks.
Edit: worked. Fan is blowing like crazy with ridiculous lag and getting increasingly hot. Damn...

----------

Fans are blasting!

simsaladimbamba · Feb 4, 2013, 09:33 PM

Quote:

Originally Posted by Squilly

Dually noted and yay! Thanks.
Edit: worked. Fan is blowing like crazy with ridiculous lag and getting increasingly hot. Damn...

----------

Fans are blasting!
Image

That is what you get with CPU intensive applications using the CPU, and the following FAQ should you inform you about that: Those Macs in their heat - a sine of over-heating? - a short story by Mister GGJstudios

hansenc · Feb 4, 2013, 10:15 PM

Actually Command + N will open new windows of the chess game without all the work to copy the app over and over again.

Nermal · Feb 4, 2013, 10:17 PM

Quote:

Originally Posted by hansenc

Actually Command + N will open new windows of the chess game without all the work to copy the app over and over again.

I didn't know about that when I made my earlier post (I was at work), but Cmd-N seems to be really flaky; I just did it three times and it only generated one additional game.

derbothaus · Feb 4, 2013, 10:54 PM

Quote:

Originally Posted by duervo

OS X does not support CPU affinity for individual processes. AFAIK, the kernel handles the distribution of processes amongst a CPU's cores.

man renice

Fatt · Feb 4, 2013, 11:06 PM

duervo · Feb 4, 2013, 11:50 PM

Quote:

Originally Posted by derbothaus

man renice

renice changes process priority. It has nothing to do with CPU affinity.

Outkast27 · Feb 4, 2013, 11:58 PM

Quote:

Originally Posted by chrise2

Ask it to play global thermal nuclear warfare. It will unlock all 1024 cores.

HAHAHA! this MF had me thinking of the Whopr when I read the op!

throAU · Feb 4, 2013, 11:59 PM

Quote:

Originally Posted by Squilly

Just to stress the computer, see what it can do, that's all. I was told by someone that it's recommended.

Handbrake to rip a DVD (or ISO of one) is a good stress test. It will max all 8 virtual cores on my MBP.

derbothaus · Feb 5, 2013, 12:30 AM

Quote:

Originally Posted by duervo

renice changes process priority. It has nothing to do with CPU affinity.

I misread your words. Priority can help (debatable) but to tack to specific cores...you be correct.
https://developer.apple.com/library/...N-AffinityAPI/

Feb 4, 2013, 08:25 PM	#1
Squilly In Time-Out Join Date: Nov 2012 Location: PA	Unlock 8 Virtual Cores on rMBP I was told there was a way to unlock all cores on a rMBP by starting 8 chess games with computer vs computer. The problem: I can only start one. How do you start multiple games?
	0

Feb 4, 2013, 08:27 PM	#2
alphaod macrumors P6 Join Date: Feb 2008 Location: NYC	What do you mean "unlock" cores? It's just a computer. It comes working with 8 logical processors. __________________ Mac Pro \| 27" iMac \| 15" MacBook Pro with Retina display \| iPhone 5 \| iPad 3 \| iPad mini
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Feb 4, 2013, 08:30 PM	#3
simsaladimbamba macrumors Core Join Date: Nov 2010 Location: in front of it	Why do you want to do what? Your Mac has one CPU with four real cores, each core having two virtual cores, giving you eight virtual cores as a whole, and if an application is written to take advantage of those, it will use them if it needs to. No need to "unlock" something. And how many threads is that today? 10? __________________ This is not
	2

Feb 4, 2013, 08:43 PM	#6
Patrick Boyle macrumors newbie Join Date: Jun 2010 Location: Jacksonville, FL	What are you guys smoking tonight? __________________ 15" rMBP 2.7Ghz 16GB RAM 512GB SSD iPhone 5 iPad 3
	2

Feb 4, 2013, 11:06 PM	#21
Fatt macrumors member Join Date: Jul 2012 Location: Miami/Gainesville, FL	__________________ Main Rig: Core i7 950 @ 4.2ghz (1.28v), ASUS Rampage III Formula, EVGA GTX 670 SLI @ 1292mhz, Mushkin 12GB @ 2000mhz, Intel 320 160GB SSD, Corsair AX850, XSPC Rasa, XSPC RX240 & RS240, MCP655. rMBP
	4

Feb 4, 2013, 08:33 PM	#4
duervo macrumors 6502 Join Date: Feb 2011	OS X does not support CPU affinity for individual processes. AFAIK, the kernel handles the distribution of processes amongst a CPU's cores. There is no way that I know of to force a process to run on a specific CPU core.
	0

Feb 4, 2013, 08:44 PM	#7
Squilly Thread Starter In Time-Out Join Date: Nov 2012 Location: PA	Just to stress the computer, see what it can do, that's all. I was told by someone that it's recommended.
	0

Feb 4, 2013, 08:44 PM	#8
chrise2 macrumors regular Join Date: Sep 2012	Ask it to play global thermal nuclear warfare. It will unlock all 1024 cores.
	5

Feb 4, 2013, 08:51 PM	#10
Asuriyan macrumors 6502 Join Date: Feb 2013 Location: Indiana	I think someone was pulling your leg.
	0

Feb 4, 2013, 10:15 PM	#18
hansenc macrumors regular Join Date: Jun 2004	Actually Command + N will open new windows of the chess game without all the work to copy the app over and over again.
	0

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