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1. #Mac vs windows laptop for parallel programs movie
2. #Mac vs windows laptop for parallel programs full
3. #Mac vs windows laptop for parallel programs pro
4. #Mac vs windows laptop for parallel programs code

Scalability keeps improving with newer chips and faster memory however. That’s right: memory contention and other overhead can make a 4-core system run faster than an 8-core system.

#Mac vs windows laptop for parallel programs full

This is why one can observe full CPU utilization on an 8-core system How, but see only only -0.1X - 1.5X speedup over a 4-core system-the cores are “actively waiting” for memory access.

#Mac vs windows laptop for parallel programs movie

Like the Ladies bathroom at a movie theatre, a long queue can form waiting for access-the cores actually become idle for much or even most of the time that they are allegedly computing they are forced to wait most of the time for their memory access operations to complete. With the network or internet, it’s mega bits per second (8 bits per byte) in all cases it is bandwidth or the size of the “pipe” that places a hard limit on anything that wants to push (write/upload) or pull (read/download) through it.Īll CPU cores must share access to the same physical memory and therefore have to take turns to read from or write it. With memory, it’s gigabytes per second: that’s bandwidth. Think of a garden hose as compared with a fire hose-the fire hose allows a much greater volume of water to pass through it per unit time: perhaps 200 versus 5 gallons per minute. Memory bandwidth (speed) is a major “bottleneck” with multi-core systems. Great for travel or for desktop! Memory bandwidth Large numbers of CPU cores are the future, along with using cores from more than one machine. Yet in too many cases, it’s simply bad engineering, sloppy design for today’s computing world, where CPU clock speeds are not increasing, but the number of CPU cores is doubling every 18 months. Only one person can drive a car at a time! There are plenty of computing tasks that have such limitations parallel execution (threading) has been the subject of computer science research for many decades. Some applications will run at the same speed on single-core, dual-core or eight-core systems because the job they are doing can’t be divided into pieces easily.

#Mac vs windows laptop for parallel programs code

This means that an 8-core system can potentially run about 4 times faster than a dual-core system! Actual performance gainsĪctual multi-core performance gains are subject to memory bandwidth limitations (competition for access to memory by multiple cores), synchronization (“handshake”) overhead, and the programming skill of the application developer-threaded code is not easy to write well or correctly. This is called task threading or simply threading or threaded execution.Īssuming you’ve configured your Mac for optimal performance How, more and more applications in 2008/2009 are running or will soon run at speeds in direct proportion to how many CPU cores your Mac has. How many coresīy working in parallel, multiple CPU cores can greatly accelerate multiple tasks, or portions pieces of the same task. This will slowly change, as market pressures come to bear, but four cores is enough for most users, with six cores being plenty except for specialized tasks. There are still many inefficient applications which do not use the available CPU cores, confining their activities to “single thread” mode, using only a single core. Whither Adobe Photoshop CS4, with its gross underutilization of even two cores for many tasks?

The emerging multi-core reality is the impetus for new technology from Apple, and increased attention from application developers to exploiting all that computing power. Future Intel chips will have even more cores. On each physical CPU, there can be more than one CPU core (“core”), with each core fully capable of running the entire system and applications all by itself.Īs of 2012, Intel chips used in Macs have 2/4/6/8/12 cores.

#Mac vs windows laptop for parallel programs pro

The MacBook Pro, MacBook, iMac all have a single CPU chip certain models of the Mac Pro (2012) have dual CPUs, each with four or eight cores. Updated - Send Feedback Related: bandwidth, CPU cores, Mac Pro, MacBook, memory, memory bandwidth, Photoshop, RAIDĬPU is a loosely-used term, but traditionally referred to a single physical computer chip, the computing brain inside your Mac.