To check the number of cores for a CPU in a virtual machine, you can use one of these utilities:

• Coreinfo
  Coreinfo is a Microsoft command-line utility, developed by Mark Russinovich. It displays the mapping between logical processors and the physical processor, NUMA node, and socket on which they reside. It also provides information on the cache assigned to each logical processor.
  
  To check the distribution of cores across socket, use the coreinfo -c -s command. To download and install coreinfo, click here.

• CPU-Z utility
  CPU-Z is a freeware application for Microsoft Windows operating systems and it provides information about CPU, Processor, Cache, Memory, System board, Graphics, and other hardware features. To download and install CPU-Z, see http://www.cpuid.com/.

In the figure below, the cpuid.coresPerSocket is set to 4 and, therefore, the number of cores per CPU is 4.

 

 

For information about setting the number of cores per socket in a virtual machine, see Setting the number of cores per CPU in a virtual machine (1010184).

Additional Information

• CPU – Is the portion of a computer system that performs the instructions of a computer program. It is the primary element that carries out the computer’s functions. 
• Core – Is a logical execution unit containing an L1 cache and functional units needed to execute programs. Cores can independently execute programs or threads. 
• Socket – Is a physical connector on a computer motherboard that accepts a single physical chip.

Setting the number of cores per CPU in a virtual machine

Some operating system SKUs are hard-limited to run on a fixed number of CPUs. For example, Windows Server 2003 Standard Edition is limited to run on up to 4 CPUs. If you install this operating system on an 8-socket physical box, it runs on only 4 of the CPUs. The operating system takes advantage of multi-core CPUs so if your CPUs are dual core, Windows Server 2003 SE runs on up to 8 cores, and if you have quad-core CPUs, it runs on up to 16 cores, and so on.

Virtual CPUs (vCPU) in VMware virtual machines appear to the operating system as single core CPUs. So, just like in the example above, if you create a virtual machine with 8 vCPUs (which you can do with vSphere) the operating system sees 8 single core CPUs. If the operating system is Windows 2003 SE (limited to 4 CPUs) it only runs on 4 vCPUs.

 

 

Note: Remember that 1 vCPU maps onto a physical core not a physical CPU, so the virtual machine is actually getting to run on 4 cores.

 

Considering that 1 vCPU is equal to 1 CPU is an assumption for the sake of simplification, since vCPUs are scheduled on logical CPUs which are hardware execution contexts. These tasks can take a while in the case of a single core CPU, CPUs that have only 1 thread per core, or could be just a thread in the case of a CPU that has hyperthreading.

Consider this scenario:

In the physical world you can run Windows 2003 SE on up to 8 cores (using a 2-socket quad-core box) but in a virtual machine they can only run on 4 cores because VMware tells the operating system that each CPU has only 1 core per socket.

VMware now has a setting which provides you control over the number of cores per CPU in a virtual machine.

This new setting, which you can add to the virtual machine configuration (.vmx) file, lets you set the number of cores per virtual socket in the virtual machine.

 

To implement this feature:

1. Power off the virtual machine.
2. Right-click on the virtual machine and click Edit Settings.
3. Click Hardware and select CPUs.
4. Choose the number of virtual processors.
5. Click the Options tab.
6. Click General, in the Advanced options section.
7. Click Configuration Parameters.
8. Include cpuid.coresPerSocket in the Name column.
9. Enter a value (try 2, 4, or 8) in the Value column.Note: Ensure that the number of vCPUs is divisible by the number of cpuid.coresPerSocket in the virtual machine. That is, when you divide the number of vCPUs by the number of cpuid.coresPerSocket, it must return an integer value. For example, if your virtual machine is created with 8 vCPUs, coresPerSocket can only be 1, 2, 4, or 8.
   
   The virtual machine now appears to the operating system as having multi-core CPUs with the number of cores per CPU given by the value that you provided in step 9.
   
10. Click OK.
11. Power on the virtual machine.

For example:

Create an 8 vCPU virtual machine and set cpuid.coresPerSocket = 2. Window Server 2003 SE running in this virtual machine now uses all 8 vCPUs. Under the covers, Windows sees 4 dual-core CPUs. The virtual machine is actually running on 8 physical cores.

 

Note:

• Only values of 1, 2, 4, 8 for the cpuid.coresPerSocket are supported for the multi-core vCPU feature in ESX 4.x.
• In ESX 4.0, if multi-core vCPU is used, hot-plug vCPU is not permitted, even if it is available in the UI.
• Only HV 7 virtual machines support the multi-core vCPU feature.

Important: When using cpuid.coresPerSocket, you should always ensure that you are in compliance with the requirements of your operating system EULA (Regarding the number of physical CPUs on which the operating system is actually running).

Difference between Plenum & Riser Cat5/Cat6 cable

Plenum vs. Riser

Cable Ratings

Plenum (CMP) Rated Cable
Complies with NFPA-262 and UL-910. Only cable allowed in spaces defined as air plenums such as raised flooring systems and air handling ducts. Plenum cables must self extinguish and not reignite. They also produce less smoke than traditional PVC cables. The smoke and fumes are toxic.

Riser (CMR) Rated Cable
Comples with UL-1666. Defined for usage in vertical tray applications such as cable runs between floors through cable risers or in elevator shafts. These spaces cannot be used for environmental air. These cables must self extinguish and must also prvent the flame from traveling up the cable in a vertical burn test.

Other Cable Ratings:

Low Smoke Zero Halogen (LSZH) Rated Cable
Used in shipboard applications and computer networking rooms where toxic or acidic smoke and fumes can injure people and/or equipment. Examples of Halogens include Fluorine, Chlorine, Bromine, and Iodine. These materials when burned produce acidic smoke that can harm people and computer equipment. Low Smoke means the cable does not produce the heavy black soot and smoke common with PVC cables. These cables will self extinguish but cannot pass UL-910 or UL-1666 for a plenum or riser rating. 

General Purpose (CM, CMG, CMx) Cable
Complies with UL-1581 testing. Will burn and partially self extinguish. Not for use between build floors or in air plenum spaces. Often these cables are used for workstation cables and patch cords.