Feeds

Idle wild: how Intel's mobile Core i7 speeds up to slow down

Turbo Boost, Thread Parking and the drive for low-power performance

  • alert
  • submit to reddit

Internet Security Threat Report 2014

Again, only real-world tests will show how valid the claims made by Intel and Microsoft are - and whether they make a difference when so much system power is drawn by, say, the display, a device that's consuming Watts whether the CPU's on a light load or a heavy one.

Snow Leopard's Grand Central Dispatch system, which allows software developers to stop worrying about threads at all and leave it all to the OS has the potential to allow Mac OS X greater control over thread scheduling, but it's not clear from Apple's GCD documentation whether its scheduler is as HT savvy as Windows 7's is.

Intel Turbo Boost

Only four threads to schedule? Thread Parking ensures they'll only be assigned to physical cores

The Nehalem-derived Xeon 5500 processors Apple builds into the Mac Pro and Xserve have HyperThreading, though the CPUs in none of its other machines yet do, so this feature shouldn't be alien to Apple.

Linux certainly does support HyperThreading and has for years. It has also supported thread parking for quite a while too, kernel scheduler hacker Ingo Molnar told Register Hardware.

Indeed, the next major kernel release, 2.6.32, due in December, will include "further tweaks" for SMT load-balancing, he said, allowing the scheduler to "adapt to the momentary performance profile of each socket, core (and thread) on the system - even if they are asymmetric".

In short, it'll not simply favour real cores over virtual ones but also faster-running physical cores over slower ones, monitoring the state of each and switching threads as each core's frequency changes. The feature will be built into 2.6.32 but disabled by default. ®

Providing a secure and efficient Helpdesk

More from The Register

next story
Don't wait for that big iPad, order a NEXUS 9 instead, industry little bird says
Google said to debut next big slab, Android L ahead of Apple event
Netscape Navigator - the browser that started it all - turns 20
It was 20 years ago today, Marc Andreeesen taught the band to play
A drone of one's own: Reg buyers' guide for UAV fanciers
Hardware: Check. Software: Huh? Licence: Licence...?
Jaguar Sportbrake: The chicken tikka masala of van-sized posh cars
Indian-owned Jag's latest offering curries favour with us
The Apple launch AS IT HAPPENED: Totally SERIOUS coverage, not for haters
Fandroids, Windows Phone fringe-oids – you wouldn't understand
Apple SILENCES Bose, YANKS headphones from stores
The, er, Beats go on after noise-cancelling spat
Here's your chance to buy an ancient, working APPLE ONE
Warning: Likely to cost a lot even for a Mac
Xiaomi boss snaps back at Jony Ive's iPhone rival 'theft' swipe
I'll have a handset delivered. Judge us after you try us...
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Win a year’s supply of chocolate
There is no techie angle to this competition so we're not going to pretend there is, but everyone loves chocolate so who cares.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.