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Questions tagged [hyper-threading]

A technology by Intel to increase processor throughput, by adding independent logical processing units in each core (and thus exposing two times the number of cores to the operating system).

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Why is my dual-core CPU recognized as a quad-core one?

My processor is an Intel Core i3-380m. As you can see, it's 2 cores and 4 threads. Although, both Ubuntu 11.04 and Windows 7 seem to think it's a quad-core CPU: Why is this? Is it because there are ...
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24k views

What is the difference between hyper-threading and multiple cores?

In a conversation with the network administator, I mentioned that my machine was a dual-core. He told me it was not. I brought up the task manager, went to the perfomance tab, and showed him that ...
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How much speedup does a hyper thread give? (in theory)

I'm wondering what the theoretical speedup is from hyper threaded CPUs. Assuming 100% parallelization, and 0 communication - two CPUs would give a speedup of 2. What about hyper threaded CPU?
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What is hyper-threading and how does it work?

I've heard the term hyper-threading thrown around a bit recently, what exactly is hyper-threading and why is it important?
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How does Windows processor affinity work with hyperthreaded CPUs?

How does Windows processor affinity work with hyperthreaded CPUs? Let's use an example (pictured) of a system with four cores, each with a hyper-threaded virtual core. Which cores correspond to each "...
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8k views

Task Manager is saying the system is running with over a thousand threads

I opened up Task Manager and looked under the "System" area and saw: Threads: 1337 Since I have a dual-core processor with hyper-threading available (meaning four threads), how is it possible to ...
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3answers
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Disable Hyperthreading in the Windows 7 registry

Some bios's Do Not have the option to disable Hyperthreading of the CPU, it there a way to disable it in the Windows 7 Registry? Or a tool or software? I know about msconfig boot tab (advanced ...
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4answers
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Quad Core host with hyper-threading, how many processors to configure in VirtualBox?

I have a quad-core i7 processor with hyperthreading (8 logical cores), when I configured a virtual machine to use 8 processors, VirtualBox gave me a warning saying that I only have four cores (which ...
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3answers
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cpu load measure with hyperthreading on linux

How can I get the true usage of a multicore hyperthreading enabled cpu? For example lets consider a 2 core CPU, expressing 4 virtual cores. A single threaded workload would now show up as 100% in ...
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1answer
9k views

See if Mac OS X has enabled hyperthreading?

There is a way of disabling hyperthreading on Mac OS X: How to disable HyperThreading on Mac OS X Lion? Is there a Terminal command of seeing whether Mac OS X has hyperthreading enabled?
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3answers
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Single Threaded Qaud Core v.s Hyper-Threading Dual Core [duplicate]

Let's say we have two CPUs, One is Quad Core 3.2 Ghz with 4 Cores, and We have a Dual Core 3.2 Ghz with 2 Cores with 2 threads in each Core (Hyper-Threading). My assumption as a programmer will be, ...
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Should I disable hyperthreading in an Intel CPU?

I have a laptop with Intel i5 M430 2.27GHz. The CPU has TWO REAL cores but it also has some kind of virtualization so Windows sees it as 4-core. In a REAL dual core CPU, a single threaded program ...
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3answers
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What is the difference between multithreading and hyperthreading? [closed]

I've heard the terms hyper-threading and multi-threading, but what exactly is the difference between them? What kind of Intel processor uses them?
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1answer
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Number of cores available to VMware Player limited to physical cores or hyperthreaded cores?

I have an i7 with 2 physical cores, because of hyper threading Windows 7 reports 4 cores (at least in the Task Manager). My question is, when allocating cores to a VM in VMWare Player is it taking ...
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4answers
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Performance-impact of Hyper-Threading

I just read an article on Heise Online (look at the table, the rest is German) which claimed, that Hyper-Threading slows down single-threaded programs although they don't use the second thread of a ...
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1answer
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How does the Windows 10 scheduler deal with Hyper Threading since Core Parking is disabled by default for Intel CPUs?

I'm running Windows 10 (1607) on an Intel Xeon E3-1231v3 CPU (Haswell, 4 physical cores, 8 logical cores). When I first had Windows 7 installed on this machine, I could observe that four out of eight ...
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3answers
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CPU monitoring: hyper threading, current clock speed

I think it'd be interesting if it were possible to check out at how much Ghz each one of my cores is running. Is it possible, at all?
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Is there a significant performance difference between virtual and real cores? [duplicate]

Possible Duplicate: Hyper-Threading and Dual-Core, What's the Difference? Most Intel processors feature what they call "hyperthreading," basically another virtual core for each physical core. ...
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2answers
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How to query Intel® Hyper-Threading current state and how to enable/disable it?

How can I see if my Intel® Hyper-Threading is enabled or disabled on my Windows 7?? There is a way to change it?
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1answer
6k views

What are “hyperthreading” and “virtual cores”?

I'm new in this computer terms. So anyone can explain to me what "virtual cores" and "hyperthreading" are at greatest detail a layman can understand? People told me that virtual cores are imaginary ...
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1answer
2k views

Why does my non-hyperthreading enabled CPU claim it has hyperthreading?

I was checking my processor for the aesni (hardware aes, "aes" flag) when I discovered the "ht" flag. This, on i7 processors denotes the CPU's ability to do hyperthreading, however, since I own a i5-...
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4answers
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Why Hyper-Threading provides 2 virtual cores but not more?

Here is an explanation of Hyper-Threading found on Wikipedia: For each processor core that is physically present, the operating system addresses two virtual (logical) cores and shares the workload ...
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Hyper Threading vs overclocking

What is the difference between these two, and under what circumstances would I want to implement them? Are there circumstances when I would only want 1 and not the other? According to Wikipedia, ...
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2answers
13k views

/proc/cpuinfo gives CPU info per core or per thread?

My CPU has 2 cores, so I can see two parts in /proc/cpuinfo. But, I want to know if CPUs that support Hyper-Threading (or similar tech), will /proc/cpuinfo give CPU info per core or per thread (or ...
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1answer
881 views

Why are 16 threads more efficient than 8 on an i7 with hyperthreaded 4 cores? (Robocopy)

In Windows 8.1, I am using Robocopy to save 2 servers' data onto a dedicated PC's storage space. The data volume is 147,314 files in 4,110 folders (66,841,845,760 bytes). All 3 involved PCs feature ...
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How can a single threaded application like Excel 2003 take more than 50% of a hyper-threaded or dual-core CPU in task manager?

I'm waiting for Excel to finish a recalculation and I notice that the CPU usage as reported by Task Manager occasionally spikes to 51% or 52% on a Pentium 4 with hyper-threading. How is a single-...
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2answers
10k views

How to disable HyperThreading on Mac OS X Lion?

Unlike my old Windows Boxes and Linux Boxes, I do not have access of something similar to a BIOS on my MacBook Pro. I want to disable Intel i7's HyperThreading (so 4 cores look like 4 cores and don't ...
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1answer
2k views

Eclipse: would more CPU cores with HyperThreading help increase speed?

I'm programming a very large project in Eclipse. Right now I use a dual core machine with 2GB RAM, but Eclipse is sometimes busy for minutes (refreshing/indexing/building), so I'm upgrading to a new ...
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0answers
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Can I tell how much multi-threading I'm using each day?

Is there a way to determine (or even better, to log) how much benefit I'm getting from my computer's multi-threading capabilities? Background: My higher-ups are proposing to give me and my team new ...
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1answer
1k views

Single-threaded program takes too low CPU?

I am using Windows 7 Professional, Intel i7 CPU. I know the i7 has Hyper-Threading and I assume this is the reason. While running a single-threaded program, I saw that it only uses 12-13% CPU in Task ...
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1answer
861 views

Does the i5 processor in the 2011 iMac allow hyper threading?

On the intel website, it says that the i5 processor uses hyper threading. Elsewhere on the internet I've read various conflicting reports. Can anyone give me a definitive answer?
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1answer
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How should I interpret this /proc/cpuinfo data?

I'm using Intel Xeon E5-2620 processor. There is something I'm confused about. I'm using Linux and in /proc/cpuinfo it says: model name : Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz According to the ...
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0answers
969 views

Disable hyperthreading on MacPro Xeon

We need to disable hyperthreading on several MacPros. We have just two types of Macs - Dual QuadCore 2.4 "Westmere" and single CPU SixCore 3.66 "Westmere". All machines run 10.6.8 For some strange ...
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2answers
2k views

Running threads on a non hyper-threading Intel processor

Intel Pentium Processor E5700 (2M Cache, 3.00 GHz, 800 MHz FSB) does not have hyper-threading but it has has 2 cores so I am assuming it has 2 threads Now if I write a heavy number crunching program ...
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2answers
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do I get half the CPU speed for a single thread if HT is turned on? [duplicate]

If I have a single 2.6GHz core for example would it mean that with hyperthreading I have only 1.3GHz for a single thread that my app have or is it on demand only if I will use (lets say my app is the ...
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1answer
16k views

disable hyperthreading on a multi-core Dell PC

I have a Dell desktop running Windows 7 Professional. I think the processor is an Intel Core i7-2600 Recently a computer expert who specializes in Linux clusters was looking at my desktop PC and ...
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1answer
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CPU threads not being used

I recently got a new Thinkpad T570. I'm running Fedora 27. It has a i7-7600U processor that should have 2 cores and 4 thread according to Intel (https://ark.intel.com/products/97466/Intel-Core-i7-...
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2answers
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Physical vs logical vs virtual cores

My processor has 4 physical cores. Maximum of 8 virtual cores per core. Does the following applies: if hyper threading is enabled than 4x 2 = 8 logical cores. Which means 8 x 8 = 64 maximum virtual ...
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2answers
785 views

Running Ubuntu in VirtualBox under Windows 8.1 doesn't use CPU on 100%

I am running Ubuntu 14.10 64 bit under Windows 8.1 64 bit using VirtualBox 4.3.10. I have an Intel Core i5-2410M CPU, with 2 physical cores and enabled HyperThreading and virtualization. I have set ...
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0answers
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Turning off Hyperthreading in Windows 10 in Gigabyte P57 Laptop

I don't see an option for hyperthreading or HT in my bios even though I know hyperthreading is enabled. How can I disable it? Here's the screenshots from all the BIOS tabs: *What is the solution, if ...
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0answers
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How to log/get a report on threading performance in Windows?

So with programs like Process Explorer and Process Hacker you can see what the individual threads from a given process are up to. However as far as I can tell its just an active monitor with no way to ...
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1answer
2k views

VirtualBox recognise all threads as cores or only physical cores for dual core Core i7?

When I run VirtualBox (or other virtualisation software) it lets me select how many cores I like to allocate to a virtual machine. Since I have a dual core 2.66gHz Intel Core i7 with hyperthreading, ...
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2answers
1k views

hyper threaded core i3 vs non-hyper threaded core i5

I have been searching around and comparing specifications to build a budget gaming PC. On the Intel site, i have been comparing CPUs and I noticed that the I3 CPUs, while only having 2 physical cores ...
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2answers
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How many threads can I run when using an Intel Core Duo CPU to speed up bulk data download from Amazon S3 in a custom application?

How might I find out the maximum number of threads I can use? I'm new to programming, so I'm trying to figure out what I need to know. I have 950 GB of files to download from Amazon S3. I was thinking ...
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2answers
3k views

Why is it said that 'The longer the pipeline, higher the processor clock rate' [duplicate]

I have been recently going through the hyper threading technology of Pentium 4. The number of pipeline stages is high in P4 and is said that it will increase the speed of clock rate. How is that ...
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2answers
787 views

Again about Hyper Threading

I have Asus 1025c with dual-core atom with hyper-threading enabled. When I play games, processor load rate always less than 25% (1 core). Is that means, that game (running single thread) occupies only ...
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1answer
417 views

Full HD and hyperthreading

I have 3 GHz Pentium 4, and it's not best for playing full HD videos. I noticed, that when I'm playing full HD video, only 50% of my cpu is used, so only one of virtual cores is doing it's job on full ...
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2answers
145 views

Why does Windows 10 have CPU core parking disabled?

Why does Windows 10 come with core parking disabled? It seems to me, that core parking is good in most cases. Especially considering Turbo Boost does not work until some cores are parked. Also why ...
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1answer
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If Affinity on Windows is set on 1 thread only, does it eliminate problems with thread-unsafe software?

Say I have a third party software executable I can't really edit or alter in anyway or debug properly. I suspect it has issues with multithreading in a way that it segfaults the application due to ...
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2answers
1k views

Hyperthreading Calculating Load [duplicate]

I have a dual core core i5 with hyperthreading. Since hyperthreading allows for unused cpu time to be used by other processes, why would this make it seem like 4 logical processors (2 per actual core)....