Questions tagged [cpu]

The part of a computer responsible for performing computations, often referred to as a processor.

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Why can't you have both high instructions per cycle and high clock speed?

The Megahertz Myth became a promotional tactic due to differences between the PC's INTEL 8086 processor and Apple's Rockwell 6502 processor. The 8086 ran at 4.77MHz while the 6502 ran at 1MHz. ...
dobus's user avatar
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33 votes
6 answers
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How many physical CPUs does my machine have?

I am a bit confused about the number of CPUs my server has. It is running on Intel(R) Xeon(R) Gold 6242R CPU @ 3.10GHz which according to official Intel docs contains 20 physical cores. The problem ...
eddyP23's user avatar
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32 votes
3 answers
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Is there a command in Linux to know the processor number in which a process is loaded?

Is there any command in Linux to figure out, given a process, which processor the process is running? I am interested in figuring out the CPU busy and CPU idle time of that processor.
kumar's user avatar
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20 votes
5 answers
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CPU is stuck at its minimal frequency

The i7 CPU in my ThinkPad X220 with Windows 10 is stuck at a very low frequency - 0.78GHz to be precise. I restarted the PC I switched power plans to high performance I double checked that maximum ...
Tomáš Fejfar's user avatar
20 votes
4 answers
39k views

How to set processor affinity on OS X?

How do you set processor affinity in Snow Leopard on a MacBook Pro?I know in Windows you could just switch it in Task Manager.
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17 votes
1 answer
52k views

How to allocate more processor power to my (Ubuntu-based) Virtualbox system in Windows 7?

I have installed an 32-bit Ubuntu based Linux OS, Elementary, on a VirtualBox installed in Windows 7 (32 bit) , on a 64-bit laptop which has a 2-core Intel i3-2330 CPU @2.20Ghz, and 4GB RAM (2.45 ...
user avatar
16 votes
3 answers
25k views

How to limit an entire user to less than 10% of cpu, not just process?

I am running centos, cpanel/whm, and I have cpulimit installed. The problem I am having is one of my users is using an extreme amount of cpu usage. Over 100% consistently and it's slowing down my ...
user7783780's user avatar
15 votes
4 answers
32k views

Can a single-threaded program be made to use multiple cores?

The title says it all: is there a way to get an older program designed to use a single CPU core to use multiple CPU cores?
Chris's user avatar
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13 votes
2 answers
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How do I get AVX support in QEMU?

I want to play with the new AVX instructions. I saw that QEMU might have support, so I built it from Git (yesterday). I set the CPU to SandyBridge and I booted Tiny Core Linux. TCL has kernel 3.0 and ...
Janus Troelsen's user avatar
13 votes
5 answers
3k views

Are there separate processors for servers?

To my knowledge a server PC and a desktop PC can have the same processor, but someone told me that servers are equipped with more powerful processors (that is these processor are designed for servers ...
TheTechGuy's user avatar
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12 votes
4 answers
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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 ...
Anthony's user avatar
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12 votes
8 answers
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Intel CPU using low clock for no reason

I've got a strange problem with my computer: Since a few days I notice that it sometimes is much slower than it should be. When I open the Task Manager, this is what I see (sorry for the German): It ...
Johann Bauer's user avatar
12 votes
3 answers
13k views

What is meant by a 32 bit processor?

What is meant by a 32 bit processor, or generally an n-bit processor?
softwarematter's user avatar
11 votes
2 answers
4k views

How does hibernation work?

I'm wondering how hibernation works. Obviously it writes the contents of RAM to disk, but is there anything else? does it save/restore CPU state? cache state? anything else?
RCIX's user avatar
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10 votes
4 answers
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How fast is each core in a dual-core processor?

My Macbook has a 2.4 GHz dual core processor. Because it has two separate cores, that means it can execute two functions at once, right? So does that mean each core is approx. 1.2GHz each (for a ...
Josh Hunt's user avatar
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10 votes
3 answers
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CPU temperature too high but fan not running at max speed

My processor fan never runs on full speed event though my processor temperature is going so high. I am using HWMonitor (also speedfan) to record temperatures and my temperature readings in normal are ...
Nullpointer's user avatar
9 votes
2 answers
4k views

Maximum CPU Temperature for Core 2 Duo E6400

What is considered to be the highest safe CPU temperature when overclocking? I have a Core 2 Duo E6400 overclocked to 2.85GHz with 1.2vCore. This runs at 29C idle and 45C under load. These ...
GaryJL's user avatar
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7 votes
1 answer
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What does CPU usage for a process actually mean

Assume the computer has a single core - what exactly does it mean for process A to be running at 100% CPU capacity vs (lets say) 10% CPU capacity. If the CPU was 2.0 GHz, does that mean in a time ...
Dave Stibrany's user avatar
7 votes
4 answers
14k views

CPU makes an electric leak like sound

For a while my computer have been making a electric leak like sound whenever the CPU usage gets high. However, lately it started to make it more often. For example with anti-virus searches and malware ...
dagcilibili's user avatar
7 votes
1 answer
13k views

How can I see the evolution of the CPU temperatures in the SpeedFan log file? [closed]

I run SpeedFan in Windows 7 Professional (32-bit) and found some log files in C:\Program Files\SpeedFan named SFLog20110717-0001.csv through SFLog20110717-0009.csv. I opened them, hoping to see a log ...
rco's user avatar
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7 votes
2 answers
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Why does System Properties display two different frequencies?

My System Properties window has the below text (also see screenshot). What does the "1.20 GHz " refer to? Hewlett-PackardHP Compaq dc7700p ConvertibleIntel(R) Core(TM)2 Duo CPU E4400 @ 2.00GHz ...
AngryHacker's user avatar
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7 votes
3 answers
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How can I track and log CPU and memory usage on a Mac?

I know I can use Activity Monitor (as well as a slew of 3rd party applications) to monitor the usage of RAM and CPU on my Mac. However, I want to capture a log over an amount of time so that I can ...
RSH's user avatar
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7 votes
3 answers
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Can someone clear up the terms Core Duo CPU, Quad Core, Dual CPU, etc.?

I'll be buying a new computer in the next couple months and want to understand the dual/duo/two CPU issue: Core Duo CPU (is this one "duo" CPU or two? Quad Core (four cpus?) Dual CPU (two cpus?) 2 ...
Edward Tanguay's user avatar
6 votes
3 answers
2k views

How to unglue microprocessor from heat sink?

I disassembled a Dell Precision 530 and replaced 5! bad capacitors. I tried to reassemble it, but I realized that I cannot succeed unless I can remove the microprocessor from the heat sink. The ZIF ...
Mike's user avatar
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6 votes
1 answer
5k views

Does it shorten the life of CPUs/GPUs to be running all the time as opposed to idling? [closed]

Some of my friends have their hardware maxed out all the time. Whether rendering huge 3d animations, generating Bitcoins, or running intense screensavers. It makes intuitive sense that CPUs/GPUs ...
dvcolgan's user avatar
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6 votes
3 answers
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Set default processor affinity for all applications

I'm trying to improve CPU performance in a game, to do this I want to try giving it 2-4 CPU cores that run ONLY that application, and no windows related services. Is there I was where I can set the ...
Novicode's user avatar
  • 197
6 votes
1 answer
19k views

Why do we need multiple levels of cache memory?

In general a cache memory is useful because the speed of the processor is higher than the speed of the ram (they are both increasing in speed but the difference still remains). So reducing the number ...
Kami's user avatar
  • 165
6 votes
4 answers
49k views

CPU Temperature required for auto-shutdown

At what temperature do most motherboards/cpus power down to prevent damage? And what determines this? Is it the bios, the motherboard, the cpu itself? I have a cpu that stays on in the bios until ...
Tomasi's user avatar
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6 votes
1 answer
8k views

How is the percentage of CPU usage calculated?

In my Ubuntu 12.04, with psensor, I saw a percentage number updated for cpu usage. I wonder how this percentage caculated? Specifically, what is the numerator and denominator in the ratio? Thanks!
Tim's user avatar
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5 votes
2 answers
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what is CPU family?

What is the CPU family in this case? And CPU cores meens the number of cores that a prossessor has, no?
Roxana Lupu's user avatar
5 votes
2 answers
16k views

DMI 2.0 vs 8.0 GT/s QPI?

How can I compare directly one Intel Xeon E5 1xxx CPU with one E5 2xxx, when it's about the communication speed with memory and peripherals? 1xxx use DMI 2.0, while 2xxx QPI. Let's say the processor ...
Blazer's user avatar
  • 53
5 votes
2 answers
6k views

Assign an individual core to a process

What I'm trying to implement is to run a python script on it's own core on Raspberry Pi 2 with Debian. One can use taskset to bind a process to particular core. But I need this core to be free of OS's ...
Leonid's user avatar
  • 153
5 votes
3 answers
20k views

Is my i7 CPU running too hot?

Here's my setup Intel i7 940 - stock speed 12GB DDR3 RAM ATI Radeon HD 4800 Series 2x 10k RPM Velociraptor Hard drives At no load, room temperature my cpu cores consistently read: 43 43 46 43 (...
Giovanni Galbo's user avatar
5 votes
4 answers
956 views

Simple way to compare processors

Today, comparing processors is obviously not just looking at the frequency and the number of cores. When choosing a new PC, how do you compare processors? Is there some resource, like a site or ...
houbysoft's user avatar
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5 votes
1 answer
4k views

Windows 10 slowly increases RAM usage on 2 different PCs

I have 2 computers with Windows 10: PC: Windows 10 Education 1803 (April Update) Intel Core i5 8400 Crucial Ballistix Sport LT 16GB (2x8GB) DDR4 2400 MSI GeForce GTX 1060 3GT OC, 3GB GDDR5 MSI Z370 ...
SuperMartas's user avatar
5 votes
2 answers
9k views

Why does my Intel CPU underclock itself automatically?

I have an Intel i3 350m and a Core 2 Quad 8300. The 350m is 2.2ghz, while the Core 2 Quad is 2.5ghz. With both, while looking at CPU-Z, they underclock themselves at seemingly random intervals (even ...
Simon Sheehan's user avatar
5 votes
3 answers
30k views

Task Manager shows one processor (and not multiple cores)

I've tried to find a solution, but I haven't had much luck. The photo says it all: I'm supposed to have 4 cores, but they're not showing up. What gives? msconfig advanced boot options also only show ...
Nathan C's user avatar
  • 2,722
4 votes
4 answers
27k views

How to see if turbo boost is working on I7 860 CPU?

I just build myself a new system with a Intel I7 860 CPU. When loading it using a single threaded application like Super PI, CPU-Z shows 2.933Ghz as speed. Now I understood that the I7 goes into turbo ...
Jan Derk's user avatar
  • 183
4 votes
1 answer
9k views

Relationship between CPU and Memory Clock Speeds

If I have a CPU with a maximum clock speed of say 2GHz, and I have a choice of memory which runs at say 2400MHz or 3200MHz, will getting the 3200MHz memory produce better performance, and how? I ...
davidgo's user avatar
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4 votes
4 answers
32k views

How to control the processor frequency of i5 in Windows 7?

On Ubuntu I can control the frequency of my CPU. I set it at the lowest value and then the fans are really quiet. Is it possible to do it in Windows 7 ? EDIT: The computer is a Laptop: Sony SVT 1311
Charles's user avatar
  • 245
4 votes
2 answers
265 views

Which property of CPUs is good for what?

Back in the days clock frequency used to be THE criteria to compare CPUs (or perhaps you had to take into account whether it was a DX or SX). The world was simple back then, but in these fast evolving ...
erikric's user avatar
  • 353
3 votes
5 answers
19k views

Strange cpuinfo, how many cores does these physical cpu has?

At the end of this post is my /proc/cpuinfo. I know the Physical cpu number is 2 grep 'physical id' /proc/cpuinfo|sort|uniq|wc -l 2 But how many cores does each cpu have? The 'cpu cores' shows it ...
user avatar
3 votes
4 answers
12k views

VirtualBox CPU usage 100% on host [closed]

I have installed VirtualBox 3.1.2 (latest) on my Windows 7 (x64). In the VirtualBox I've installed Windows 7 (x64). I have 4 GB RAM installed. The guest has been assigned a 1536 MB RAM. Sometimes the ...
Sarveshwar's user avatar
3 votes
3 answers
632 views

What's the relationship between CPU, RAM and performance?

I have an HP EliteBook Folio 9470m with an Intel Core i5 processor at 1.9GHz and 4GB RAM. Is it useful to buy an additional 4GB RAM memory with this CPU? Or would the extra RAM be wasted from a ...
Siemen Dilissen's user avatar
3 votes
3 answers
3k views

Lenovo laptop with Intel CPU remains at lowest clock

I have an Lenovo T440p with an Intel Core i5 4300M CPU. 8GB RAM, SSD running with Windows 7 (preinstalled). The only thing I did not like about this laptop was the screen, which I replaced (the whole ...
Jasper's user avatar
  • 181
3 votes
2 answers
2k views

System (ACPI.sys) 0x1af44 high CPU

I have a relatively old PC that runs on an ASUS 5PK SE/EPU motherboard with a Radeon HD 4870 graphics card, one SSD and one hard drive. My problem is that the processor is always at 50% usage. Here's ...
Oleksandr Makarenko's user avatar
3 votes
4 answers
36k views

CPU overheating, the fan won't speed up, but it's not the fan

I have 2 identical PCs, with the only difference being the GPU. One of the CPUs is overheating without the fan going up in speed, but if I gently press the fan manually, it speeds up as it seems to ...
Silver Phoenix's user avatar
3 votes
6 answers
62k views

CPU Fan is Loud, but the Temperature is OK (I Think)

I recently find that my CPU fan is getting louder and louder. It is now so loud that I bother to type up a question on it. The first thing I check is the temperature using Core Temp, it seems that ...
Graviton's user avatar
  • 5,680
3 votes
3 answers
5k views

Why would my computer all of sudden reset clock, show new boot screen, and run fans loud?

I bought a new computer one year ago, it's worked fine (Windows 7). A few months ago, it started to not boot unless I removed my USB headphones connected to a USB hub, everything else worked fine. ...
Edward Tanguay's user avatar
3 votes
2 answers
19k views

Does integrated graphics slow down CPU?

I always thought the CPU performs two tasks so when you disable the onboard graphics the CPU will be faster (because it has less work to do). But since I know that graphics calculation differs very ...
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