• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Does GCD auto-limit concurrent tasks to number of cores?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Does GCD auto-limit concurrent tasks to number of cores?


  • Subject: Re: Does GCD auto-limit concurrent tasks to number of cores?
  • From: Carl Hoefs <email@hidden>
  • Date: Thu, 09 Apr 2015 13:41:02 -0700
  • Importance: Normal

> On Thu, 9 Apr 2015 14:40:16 -0500, Sean McBride said:
>
> Not just IO, but memory usage too.  If you have 24 cores, and GCD spins up
> 24 simultaneous 'tasks', and each needs 2 GB of RAM, then you better hope
> you have 48 GB of RAM too, or you'll swap and easily end up dog slow.

I just now ran a small 600 task subset on an 8-core iMac, and I got these
performance numbers:

Memory usage:  800MB (100MB per task)
CPU usage:   93.75% (over all cores)
Energy impact:  Very high
Disk I/O:  800 KB/s

So, I'm thinking this should scale well to the 24 core MacPro w/32GB RAM.

Thx all for the great help!
-Carl


_______________________________________________

Cocoa-dev mailing list (email@hidden)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden


References: 
 >Does GCD auto-limit concurrent tasks to number of cores? (From: Carl Hoefs <email@hidden>)
 >Re: Does GCD auto-limit concurrent tasks to number of cores? (From: Clark Smith Cox III <email@hidden>)
 >Re: Does GCD auto-limit concurrent tasks to number of cores? (From: Ken Thomases <email@hidden>)
 >Re: Does GCD auto-limit concurrent tasks to number of cores? (From: Sean McBride <email@hidden>)

  • Prev by Date: Re: Does GCD auto-limit concurrent tasks to number of cores?
  • Next by Date: Proper switching and casing.
  • Previous by thread: Re: Does GCD auto-limit concurrent tasks to number of cores?
  • Next by thread: Proper switching and casing.
  • Index(es):
    • Date
    • Thread