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0
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1answer
102 views

What are the performance implications of Hyper-threading for single Nehalem+ CPU? [duplicate]

I am choosing between two models of servers, the major difference between them being the the availability of Hyper-Threading. Servers in question are SYS-E32-1 and SYS-E32-3 from So you Start (an OVH ...
1
vote
1answer
101 views

how does cache work on hyperthreaded Intel Xeon Processors

I am running some experiments on a research database on EC2 using a c1.xlarge instance. As far as I can tell, the c1.xlarge uses 8 hyper-threaded virtual CPUs. Amazon also says that this instance uses ...
1
vote
1answer
70 views

Acceptable linux load - count HT cores?

So the conventional notion of "acceptable load" on a *nix based box is "1.00 minus some overhead (10% give or take) per core". So if we have a 4 core machine, a load of 3.50 would be acceptable. ...
-1
votes
2answers
66 views

Multi-CPU server with CPUs of differing core counts

Is it possible to have a multi-CPU server where the CPUs do not necessarily have the same number of core counts? For example, a group of 4 at dual core and a group of four at quad core? This ...
0
votes
1answer
423 views

Linux Load Averages and HyperThreads

My rough understanding of a Linux load Average is that for every integer a CPU core is working all the time. EX 1 means on a 4 core system that 1 core is working at capacity. How does HyperThreading ...
2
votes
1answer
2k views

How to make Windows 2008 R2 see 4 CPU cores, with two single core processors , Hyperthreading enabled

I had server with old Xeon DP and Windows 2008 R2 , With hyperthreading enabled OS saw 2 CPU cores. Recently I've added second same Xeon DP , but OS steel sees 2 CPU cores. I did uninstall all cpu's ...
0
votes
1answer
183 views

Maximum CPU and hyperthreading [closed]

Hyperthreading doubles the logical cores, but doesn't double CPU resources. Linux measure CPU usage in %, allocating 100% points for each thread, thus reporting a maximum of 800% for a quad-core CPU ...
1
vote
2answers
362 views

Hyper-V, Hyperthreading, and the implications of per-core licensing [duplicate]

Possible Duplicate: Hyper-V and Hyper-threading: On or off? Can you help me with my software licensing issue? I've seen lots of people saying we should turn hyperthreading on on hyper-v ...
6
votes
1answer
688 views

Enabled hyperthreading - causes qthread creation error on Ubuntu Precise 64 bit

We recently set up an HP ProLiant DL360p server for some heavy grunt-work. For one reason or another we disabled hyperthreading in the system BIOS when setting it up. Being a dual-CPU 8-core system, ...
2
votes
1answer
433 views

Hyper-Threading & htop/system-monitor

I'm running a large set of simulations on a quad-core Xenon E5520 with Hyper-Threading enabled. My software automatically detects 8 (virtual) cores and launches 8 simulations to run in parallel. ...
2
votes
4answers
361 views

Should I expect a great increase in Oracle performance in terms of handling multiple requests switching from single to dual core?

We have an Oracle database of roughly 100 GB that runs on top of a Windows Server 2k3R2 VM in ESX in a 1 socket, 1 core configuration. Whenever it has to handle a major query it seems to get "pegged" ...
1
vote
1answer
954 views

Nginx worker_processes and multi core cpu's - Do Hyper-threading cores count?

Quite often, when reading about the recommended worker_processes for nginx it is stated that this should be set to the numbers of cores the server hosting nginx has. We were wondering if we should ...
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votes
1answer
130 views

Hyperthreading can only create two threads? [closed]

HyperThreading can only create two cores/threads ? More can not be created by design or is there any other limitation ?
1
vote
2answers
1k views

VMware ESXi Virtual Machine configuration for hyperthreading

I have a Xeon E3-1230 processor, which has 4 physical cores, but has hyperthreading so an operating system running on it sees 8 logical cores. I installed VMware ESXi and am creating virtual machines ...
2
votes
1answer
608 views

CPU Resource pool with and without hyperthreading in vmware esx/esxi

VMWare ESX/ESXI running with AMD 12core @2.2GHz. Intel 6core @2.4GHz In resource pool, with amd cpu I should see 26.4GHz available. Now it's interesting what will be shown with Intel CPU? Am I gonna ...
8
votes
3answers
8k views

Hyper Threading and Virtual Machines?

I already looked at this thread: Hyper-V and Hyper-threading: On or off?, but the only answer is Windows specific.... I am building a VM server (using Proxmox VE if that makes a difference) and was ...
2
votes
2answers
431 views

Optimal number of threads for compute-intensive task on server with Hyperthreading

When running a compute-intensive task on a server with an Intel i7 quad-core processor with Hyperthreading, is it ideal to run eight threads (for the eight virtual cores), or only four (for the four ...
1
vote
2answers
608 views

Hyperthreading on multicore processors - is it of any use? [closed]

I know hyperthreading from the time long ago where the processors used to have only a single core. The technology was really usefull then. Right now, Intel is still offering hyperthreading with 6-core ...
2
votes
2answers
2k views

Why would only half of the cores on my hyperthreaded linux server be loaded?

I have a server which is a 12 core hyperthreaded system, which means I have 24 virtual cores. I'm running 24 processes on my server, each listening on its own port and doing the same things, albeit ...
1
vote
2answers
529 views

What have I achieved through turning on hyperthreading on an old P4?

I have an old P4 3ghz with 3gb of ram. Ive rebuilt it with Windows Server 2008 to act as my test and continuous integration machine. When I went into the BIOS to make it boot from the DVD to install ...
4
votes
3answers
2k views

taskset core numbers question

I have quad core CPU with hyper threading enabled. So I have 8 logical cores. I want to limit my application to use only 4 cores and I want this 4 cores to be different physical cores. Which taskset ...
4
votes
4answers
5k views

Disable hyperthreading from within Linux (no access to BIOS)

I have a system running a financial trading application at a remote facility. I do not have access to the ILO/DRAC, but need to disable hyperthreading. The system runs Intel Nehalem 3.33GHz X5680 ...
5
votes
2answers
2k views

Is it possible to tell which cpus are hyperthreads of the same core?

I have a server that is a quad-core i-7 with hyperthreading enabled. The kernel recognises this as 8 cpus, as it should. I want to create a couple virtual hosts running on this machine. virt-manager ...
2
votes
1answer
1k views

Hyperthreading vs. SQL Server & PostgreSQL

I have read that hyperthreading is a "performance killer" when it comes to DBs. However, what I read didn't state which CPUs. Further, it mostly indicated that I/O was "cut to < 10% performance". ...
23
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8answers
23k views

Will disabling hyperthreading improve performance on our SQL Server install

Related to: Current wisdom on SQL Server and Hyperthreading Recently we upgraded our Windows 2008 R2 database server from an X5470 to a X5560. The theory is both CPUs have very similar performance, ...
0
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1answer
1k views

Ubuntu 10.04 & Intel Hyperthreading

Does Ubuntu 10.04 allow the use of hyperthreading with the new Intel i7 processor?
2
votes
2answers
969 views

Running a VM on a hyperthreaded CPU

Is it better to run a VM on a dual core hyperthreaded machine as a four core or as a two core VM. The hyperthreaded 'virtual' cores are not as fast as the real cores. Does this effect the VM?
2
votes
2answers
630 views

Hyper-V processors

I'm running a HP ProLiant DL380G6 with 2x Intel® Xeon® E5520 Quad Core Processor 2.26 GHz and 12GB of ram. I got Hyper-V installed and 3 VMs for now. If I open up task manager I can see 16 cores (I'm ...
2
votes
4answers
267 views

SQL 2005 Standard Questions

I have a question about the tempdb files and hyperthreading. Here are the sw/hw specs. Server 2008 SP2 Standard X64 SQL 2005 Standard Sp3 x64 Dual Quad Core Xeon's E5540's (HT enabled) 12 GB Ram My ...
2
votes
3answers
811 views

Will multiple processors show in /proc/cpuinfo on a kernel that doesn't have SMP enabled?

I have recently migrated an application from one server to another and am having some issues I am wondering if they are associated to HyperThreading. In regards to my question, I currently don't have ...
20
votes
5answers
17k views

Hyper-V and Hyper-threading: On or off?

With the new Xeon CPUs supporting Hyper-threading, what is the current wisdom with regard to using it (or not) on a Hyper-V host machine? I was originally under the impression that turning it on in a ...
4
votes
3answers
16k views

VMWare ESXi and Hyperthreading

I have (as some are probably tired of seeing on SF) a Dell 2950, dual 4 core 3Ghz processors running ESXi. I noticed on the VSphere management console that the server says it doesn't have ...
7
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3answers
7k views

Current wisdom on SQL Server and Hyperthreading?

Lots of articles out there (see Slava Oks's original SQL 2000 article and Kevin Kline's SQL 2005 update) recommend disabling hyperthreading on SQL servers, or at least testing your specific workload ...