With a VM you assign the number of vCPU you want that machine to have, and then pin THOSE CPU to a specific Core on the ESX host. To calculate virtual machine. Make yourself familiar with the NUMA concept and the VMware implementation of vNUMA. Emulating physical processor topology for virtual machines is critical for both execution and. So setting a reservation will help improve performance for the VM you set it on, but will not “solve” CPU ready issues caused by “oversized” VMs, or by too high an overcommitment ratio of CPU. Generally the more vCPUs per VM, the less options you give to the hypervisor to. 1. If you looked at ESXTOP, you would most likely notice that each HT was at 50% UTIL, and each PCPU (physical core) would be at 100% UTIL. Select VMs. physical processor counts. It is more akin to the share of time that the VM will recive of each clock cycle of the phyical CPU. Instead of physical processor-based licensing, it was decided that core-based is licensing is a more reliable and versatile metric to calculate the computing power irrespective of the fact that. With 8 core also 4 vCPU (is really needed) can work fine. 7 or ESXI 7 support. The default setting. Click CPUs. VMware refers to CPU as pCPU and vCPU. If your pCPU is 3. Your process use a specific CPU or many CPU. CPUs contain cores. Sorted by: 3. Without knowing other information like memory network capacity, processor usage etc. A typical vCPU-to-core ratio for server workloads is about 4:1—four vCPUs allocated for each available physical core. With more than one thread they will. 3). What a logical core is depends on your server. Microsoft provides guidelines to calculate the required compute resources for a single instance of Exchange Server (as an application) so that. A high %RDY time (use 20 percent as the starting point) may indicate the VM is under resource contention. The math is rather straight forward. 0 Virtual Topology: Performance Study | Page 2. Towards 96 vCPUs you will be well into that territory and the. Then we add in the memory we need to run vCenter in a virtual machine (8GB plus 342MB), and also figure 1GB for ESX or ESXi per server. + (Average RDY Core 3) Because ESXi assign CPU resources to each machine when CPU cores available for all machines' cores, machine has 4 cores, so it has to wait for 4 core of physical cpu. A virtual machine cannot use more CPU cores than the number of logical processor cores on a physical machine. But we usually have 3 or 4 vCPU per core without any performance problem as all VMs do not need full processor resources at the same time. Cisco design docs say that ESXi reserves approximately 1 core for itself and to take that into account. When running with lower CPU core frequency, %USED can be smaller than %RUN. vSphere 7u1 is limited to 4096 vCPUs or 32x core count. CPU use can be monitored through VMware or through the VM’s operating system. VMs with more than one vCPU1. I choosed to run 4 threads on 2 vCPU in windows VM. BTW if your search inside the community, you can find many related topics about CPU Sockets and cores relation, like the following links: pCPU vs vCPU - Relation/Ratio. 1. In vSphere, administrators assign CPUs to virtual machines in order to support the workload needs of each individual virtual machine. It is recommendable to leave 10% or more room for CPU bursts. By default, each of the added vCPU to the VMs is assigned to one of the existing pCPUs. Turn off CPU and Memory Hot Add, it's more trouble than it's worth. 3) Anything above 1000msec, performance issue. 2. A physical CPU core is controlled by the hypervisor and this is divided up into virtual CPU cores. Meeting these defined settings are required to ensure the Gateway VM is not oversubscribing the underlying hardware and causing actions that can destabilize the Gateway service (e. Procedure to set the number of cores per CPU in a VM: Step 1: Determine the total number of vCPUs to allocate to the virtual machine. In reality the vCPU count is determined by the manufacturer - it is the number of processing threads that chipset offers per core. Actually, there is not direct relationship between physical and vCPUs. Guaranteed CPU allocation for this virtual machine. 5:1 or 2:1. In this Dell white paper, the following vCPU:pCPU guidelines are established: • 1:1 to 3:1 is no problem. Use the Number of virtual processor drop-down to lower the vCPU count by 1. Hello baber,. 128 vCPUs/4 vCPUs per VM = 32 VMs. Inputs: Host specification - since many software licensing schemes are linked to server CPU specification, this tool requires information about the number of servers/hosts, the number of CPUs per server, and the number of cores per CPU. For example, an Intel Xeon CPU may have 4, 8, etc. If you save or bookmark the short link, you can return to your calculation at a later time. For ESXi 7. it is CPU0 which is nearly 100% utilised, we do have HP agents running in the console. How does VMware calculate total vCPU? 4 vCPUs per VM. there's cause for concern. But in vSphere, we still can't upgrade the vCPU to 4, so the only way going around it build more VMs (which costs. This way, we have the four vCPUs pinned to physical cores and also using them in exclusivity, in the same NUMA. Therefore, to get the CPU ready % from the ms value reported by vSphere, use the. 1) In terms of vCPUs per core I try to gauge the amount of cycles being used by the physical CPU - tools liker VMware's Capacity Planner and PlateSpins Power Recon will measure this -. It is recommended 1 vCPU for task users and 2 vCPU for knowledge users. The maximum CPU limit for a DRS cluster is the sum of numVMCPUs * GHzPerHostCore for. I know that our 2 vCPU TS on vSphere is way faster than 2 vCPU on 3. Note that these ready time values are per vCPU. Table 2. A Hyper-V vCPU is not a 1-to-1 mapping of a physical core. I am trying to understand vCPU concept in VMware. 0U2 Do the following: 1) Get a reference point from the CPU performance graph. Per virtual machine licensing. Either way I would see this as 4 vCPU in Azure. If you are trying to do safe over commit, then the best ratio varies depending on how much CPU service your VMs actually use. Allocate the minimum number of vCPUs required to meet the workload requirements. This tool calculates the number of hosts in a vSphere ESXi cluster based on the planned VM workload and host configuration. Right-click on the virtual machine and click Edit Settings. e is dual core). VMware refers to CPU as pCPU and vCPU. By default, vSphere manages the vCPU configuration and vNUMA topology automatically. Furthermore, the operator wishes to use 8 host physical CPU cores and their thread siblings for dedicated guest CPU resources. All it can do is migrate those vcpus to another physical core if the load balancer thinks it beneficial to do so, ie- if one core becomes overwhelmed with work and another core is sitting idle, ESX will migrate the vcpu to that idle core. Q1 Please clarify if following understanding of mine is correct or not: a physical CPU is namely corresponding to 1 core (embedded in a CPU socket) a VM. Ignore threads, it just the physical cores what matters. Hi. Maximum number of Cost items = 25. The vNUMA blog series by Frank. vNUMA on vSphereCPU scheduling is the process used to allocate physical CPU time slots to vCPU’s in Virtual Machines. In Google Cloud, a vCPU is typically equivalent to one physical CPU core. The exception to this would be when the guest OS and application is trying to schedule more CPU time than a single CPU core in the physical host can present (i. The total amount of clock cycles available for a VM is calculated as: (The number of logical sockets) x (The clock speed of the CPU) For example, if you configure a VM to use 2 vCPUs with 2 cores when you have a physical processor whose clock speed is 3. the others VM will be licensed if i. Share. This can increase efficiency if there is enough CPU Idle time to provide for scheduling two threads, but in practice performance increases are up to a maximum of 30% and are strongly application dependent. 4. A vCPU is a virtual CPU that is assigned to a VM. 7 Update 2 and later compatibility to have up to 256 virtual CPUs. To calculate the number of vCPUs required for a particular workload, first determine the number of physical CPU cores available on the host machine. Just a basic calculator how to size your physical hardware environment based on the amount of requested virtual cores per cluster (vCPU/CPU ratio) to avoid high CPU ready values. Some guys recommend 4 VM's to one. If your virtual machine still experiences performance issues, and if its kernel or HAL can handle switching to a single vCPU, lower the vCPU count to 1. I am trying to understand vCPU concept in VMware. e. RAM - memory capacity allocated to a VM. Essjae explained it correctly in basically saying each vCPU is borrowing CPU time from the physical processors. also we need to install a third VM of Microsoft windows server 2019 for sage with 20vCPU (2 socket). Active CPU is approximately equal to the ratio of the used CPU to the available CPU. The Physical version had 2 quad core CPUs (running at 1. Note: In this chapter, "Memory" can refer to physical RAM or Persistent Memory. processorMHz metric (in the host section) reports a nominal speed, and the virtual machine CPU metrics are normalized to the processorMHz metric. Click Edit Settings. A CPU socket is a physical connector on a computer motherboard that connects to a single physical CPU. Answer. Table 2. Hi. This gives me a vCPU ratio of 2:1. Based on design, VMware ESXi can handle the CPU oversubscription (request of vCPU more than. On the Virtual Hardware tab, expand CPU, and allocate the CPU capacity for the virtual machine. The Desired Availability Level (N+x) Next enter the total number of vCPUs and vRAM assigned (or expected to be) assigned to VMs in the cluster. First of all, you need to start with the underlying hardware, CPU and memory. Therefore, there is no blanket statement or a simple vCPU calculator. 3 physical CPU. 1 vCPU per VM. First, we need to select a virtual server and CPU. The server box have 2 physical processor each cpu have 10 cores. So setting a reservation will help improve performance for the VM you set it on, but will not “solve” CPU ready issues caused by “oversized” VMs, or by too high an overcommitment ratio of CPU resources. A vCPU, on the other hand, is a software-based variant of a computer. A general estimation is that 1 vCPU = 1 Physical CPU Core. Total. CPU: VMware Horizon DaaS recommends setting a 10x over commit ratio for CPU. In the cloud environment, each host has number of sockets (physical CPU) with defined number of cores (E. 5GHz CPUs in the host, but the guest OS in the VM is consistently requesting to be scheduled for 3. Limit Places a limit on the consumption of CPU time for a virtual machine. VM totalmhz = 2 vCPUs * 3000 MHz =. To calculate the number of vCPUs required for a particular workload, first determine the number of physical CPU cores available on the host. pCPU) The number of logical cores if hyper-threading is enabled on the host: (# of Physical Processors i. This is called "over provisioning", and is a valid technique to use. To calculate the maximum value, this is the formula: (Number of processors) * (Number of cores) * (Number of threads per core) Check this example of my machine – figure 2. Click Edit Settings on the Virtual Machine Summary Page to access the virtual machine Settings Page. 1 Calculate Bandwidth for vSphere Replication. For example, if a CPU has 8 cores and 16 threads, the maximum vCPU count is: (8. Otherwise vCD will complain when importing the file that the counters already exist. coresPerSocket larger than 64 will result in a. Let's for example say we have a server with 4 CPU's that have 4 Cores each. Similarly, Azure and Google also tend to match a vCPU to a hyper-thread rather than always 1:1 with an actual core. A virtual processor does not necessarily have to correspond to a physical processor or to a physical CPU core. A virtual machine cannot use more CPU cores than the number of logical processor cores on a physical machine. In order to set up the monitor. This gap makes it especially. Go to the Performance tab and select CPU from the left column. 4Ghz) and the virtual version now has 2 vCPUs (The ESXI host has 2. e. Each logical proc should be treated like any other core. numa. Right-click a virtual machine in the inventory and select Edit Settings. It’s calculated by taking the number of processing threads that a chipset offers per core and multiplying the number of occupied sockets: (Threads x Cores) x Physical CPU = Number vCPU. and basing it on purely vCPU then 8 would be minimum but would give little room for moving machines around for patching ESXi, covering off high CPU workloads or providing resilience for potential hardware failures, I would recommend a minimum n+1 so 9 hosts. For example, A 8 cores/ 16 threads CPU has (16 Threads x 8 Cores) x 1 CPU = 128 vCPUs. For example, "0,2-4,7" would indicate processors 0, 2, 3, 4 and 7. refer below screen shot with 1 virtual CPU socket and changing the core to. Value, per vCPU. preferHT=True – For all VMs to use hyper-threading with NUMA, add the following configuration on the ESXi Host Advance settings: numa. socket sharing between multiple SAP HANA virtual machines is not allowed. 0, there is a maximum of 32 vCPUs per physical core, and vSphere administrators can allocate up to 4,096 vCPUs to virtual machines on a single host, although the actual achievable number of vCPUs per core depends on the workload and specifics of the hardware. Second option is to use Prims PRO - Planning feature, add the new scenario and add existing workload or new. Vmware vCPU to Physical CPU Mapping - The Low Down. Core,Logical CPU,vCPU Explained. This will be discussed further in this series. g. For the vCPUs 2 and 3, is not needed. vCPU per core is essentially the over-subscription ratio, e. Solved: I want to get the ratio of vCPU:pCPU, For pCPU, do i need to taking in to account Hyperthread(Logical Processors)? Or just the Physical CPUToday, vCPU count is largely determined by the manufacturer. ) it maps to a single core. . Select a VM, and go to the performance charts and go to advanced. CPU affinity thing in here. In other words, you could build and run more than 48 VMs that have a single virtual processor core each on your system, or more. CPU: vCPU Allocation % for 1 vCPU per Core: Metric: Disabled OOTB. This hints at the 8 cores behaving more like 24 cores, but now this just. used exceed wall clock time due to Turbo Boost, or can see. pCPU available on a host: (# of Processor Sockets) X (# of Cores) = # of Physical Processors (i. Hi There, I would to like to know whether my math for CPU contention ratio is correct or not. Available CPUs: 12 (logical CPUs) Select logical processor affinity for this virtual machine. In general we always start at the lower end of the scale (say 1 vCPU with 2 GB), monitor the running VM for a while and then possibly expand the number of vCPUs or the amount of RAm assigned. Click CPUs. One of the major focuses of virtualization solutions is to enable optimized use of resources like memory and computing power, but overcommitting your hypervisor towards greedy resource management can. 625 % per vCPU. On the Virtual Hardware tab, expand CPU, and allocate the CPU capacity for the virtual machine. The general rule of thumb is: start with 1 CPU and see if performance is acceptable. Number of usable CPUs (Cores) Metric: Changed from a computed metric to an adapter published metric. In VMs, the operating system (OS) layer does not link directly to the physical hardware layer. You can configure a virtual machine with ESXi 6. Under the CPU field within the Virtual Hardware tab, select the total number of vCPUs determined in Step 1. 02-18-2015 04:51 AM. 1 Answer. For example, if a virtual machine with one virtual CPU is running on a host that has four physical CPUs and the CPU usage is 100%, the virtual machine is using one physical CPU completely. 5, ESX Server 3i version 3. What you might not have thought about is that the guest operating systems. If you need the full power of a single core for every virtual CPU, then you should avoid over-commitment. For example, if a host has 128 logical CPUs, you can configure the virtual machine for 128 virtual CPUs. However, it is possible to assign more vCPUs than you have cores. In the above case, you can provide all cores to more than one VMs. I've read several articles & forum postings on physical CPU sockets, cores, vCPUs,. 1 vCPU = 1 core per socket. Calculating vCPU Number for a Particular Workload. Let me tell you why. For more information,Below I will use some examples from VMware ESXi 5. Select Unlimited to specify no upper limit. Each vSphere license has a certain capacity that you can use to license multiple physical CPUs on ESXi hosts. To find a virtual machine, select a data center, folder, cluster, resource pool, or host. A pCPU with 6 logical processors can support up to 72 vCPUs as long as they are in Windows 7 VMs in a VDI scenario. Without overprovisioning, 1 core equals 1 vCPU so the E5-2630L and E5-2640 will give you 8 vCPUs per processor while the E5-2650 will give you 10 vCPUs per processor. AWS: Each vCPU is a thread of a CPU core, except for. If not, increment it up. These are advanced settings designed to help workloads that are cache-intensive, but not CPU intensive. This threshold cannot be overtaken because Hyper-V is. ESXi will switch the available host threads between all those 112 vCPUs staring the CPU time as fairly as possible. # of Cores 10 < < < This is number of vCPU you can assign without hyperthreading. Powering on a VM with a manually configured value for cpuid. On CPUs which support the turbo mode, CPU frequency can also be higher than the. In vSphere, administrators assign CPUs to virtual machines in order to support the workload needs of each individual virtual machine. The answer is, Yes and No. For vRAM. Core,Logical CPU,vCPU Explained. Always ensure that the size of the physical CPU and. That is, plan a pilot that uses 8 to 10 virtual machines per core. Examples of this include a uniprocessor virtual machine with affinity to a single CPU or a two-way SMP virtual machine with affinity to only two CPUs. 8 Cores x 2 (Hyper Threading) = 16 x 8 = 128 vCPUsAvailable from 9. Use the vSphere Cluster Sizing Calculator to confirm overcommitment ratios for your cluster or to validate your design. You must purchase a minimum capacity of 16 cores per CPU. By default, vSphere manages the vCPU configuration and vNUMA topology automatically. A typical vCPU-to-core ratio for server workloads is about 4:1 — four vCPUs allocated for each available physical core. Note: If the ESXi host is of version 7. Determining Host CPU and Memory Requirements. VMware's recommends 4-8 vCPUs per core - so with your configuration dual quad cores cpus VMware's recommendation would be 64 at most - If you have 50 dual vCPU VMs on a dual quad core host you will probably run into CPU contention because your are talking 100 vCPUs - but you also have an added problem that can and will affect. Total amount of CPU resources available in the cluster. a physical hardware execution context (HEC) if hyper-threading is. Multiple vCPU’s, the hypervisor CPU scheduler must wait for physical CPU’s to become available Over allocation could result in poor performance. There are three main licensing models for vSphere: Per CPU licensing that covers one CPU with up to 32 cores. Only in the absolute lightest of workloads is 1 vCPU sufficient. Typically, VMs only have access to one vCPU; however, in a cloud environment, they can have more vCPUs. The rule of thumb for Fusion is that any individual VM should have no more than N-1 physical cores assigned. The number of cores and threads of an Intel processor can be found in the Intel's Technical Specifications website by searching by processor number. Using the VMware ESXi web client (HTML5), you can monitor host and guest processor (CPU) utilization and other host CPU information. Without knowing other information like memory network capacity, processor usage etc. ESXi supports virtual machines with up to 128 virtual CPUs. I've been doing some research on vCPU to CPU ratios for a server cluster in a VMware environment. For every CPU cycle it always waits until there is a physical core available for each virtual CPU on a VM. Additionally, VMware enables you to move these virtual machines across hosts with VMware vSphere vMotion®, VMware Distributed Resource Scheduler™ (DRS) and High Availability (HA). Two vCPUs will be two cores or sockets, depending on how you configure it inside the guest, and will. Continuous Availability (CA) allows the cluster nodes to be stretched across two fault domains, with the ability to experience up to one fault domain failure and to recover without causing cluster downtime. 0GHz CPU's, the vCPU would only ever be able to use 3. Total number of assigned vCPUs to a VM is calculated as:With allocation ratio of 2:1 (2 vCPUs to every pCPU) you can allocate 128 vCPUs, but take in mind to avoid allocate more vCPU to a single virtual machine than it needs, always start small and add new vCPU only when needed. As an informal initial sizing approach, to start, assume that each virtual machine requires 1/8 to 1/10 of a CPU core as the minimum guaranteed compute power. The number of logical CPUs means the number of physical processor cores or two times that number if hyperthreading is enabled. 7. Key stats for the Intel Xeon E-2288G include 8 cores/16 threads with a 3. No matter how many vCPUs you assign you are always using all of the host's CPU cores. Now we are setting the CPU reservation to 4*2500 = 10000 (remember, together with latency sensitivity high and so on). That is, plan a pilot that uses 8 to 10 virtual machines per core. You don't allocate any cores to ESX servers. In that case, adding a vCPU to the VM may provide. The remaining 15 host physical CPU cores and their thread siblings will be used for shared guest vCPU usage, with an 8:1 allocation ratio for those physical processors used for shared guest CPU resources. Here you can see that %RDY is somewhat high for a fairly unused environment. Adding more vCPUs depends on the number of CPU cores and the number of timeslots, which are periods of times the. vSphere attempts to keep the VM within a NUMA node until the vCPU count of that VM exceeds the number of physical cores inside a single CPU socket of that particular host. CPU configuration options: 2 vCPU (1 vCPU with 2 cores or 2 vCPU with 1 core each) or 4 vCPU (1 vCPU with 4 cores, 4 vCPU with 1 core each, or 2 vCPU with 2 cores each) 8 vCPU (1 vCPU with 8 cores, 8 vCPU with 1 core each, or 2 vCPU with 4 cores each) Number of VMs: 200: 10: Launched sessions: 200: 300: Login VSI workload:. CPU Virtualization Basics. Thus, this would cause a great deal of CPU Ready because the VM would be ready to consume CPU time on 8 cores but only 4 are actually available. Calculating vCPU Number for a Particular Workload. vSphere Cluster Calculator. On the VM Options tab, click Advanced. As for a virtual CPU (vCPU) this refers to a virtual machine’s virtual processor and can be thought of in the same vein as the CPU in a traditional physical server. This is documented in Hardware Features Available with Virtual Machine Compatibility Settings under: "Maximum number of cores (virtual CPUs) per socket". • An 8 vCPU virtual machine achieved 86 percent of physical machine performance. Identify your VM by its World ID. cpu. First, we need to select a virtual server and CPU. In general, 1 vCPU is not equal to 1 CPU. VMware is one of the top virtualization software that allows you to create virtual machines and make the best use of your resources. If the physical server instead had 20 total physical cores, it could host 10 of these VMs (assuming memory, network and storage hardware are also sufficient using the. I am often asked by customers, vendors or internal teams to explain CPU capacity planning for large production databases running on VMware vSphere. Each vCPU is mapped to a logical processor, which is a physical core on your host system if you. If application vendor cannot provide any available information, my recommendation is to assign 2 vCPU per virtual machine and. Yesterday I contacted my vendor to buy a server, and I asked them how I should calculate the CPU and RAM requirements for my server, given that I want to create multiple virtual servers on it. g. I've been doing some research on vCPU to CPU ratios for a server cluster in a VMware environment. Answers. g. We have a 2500 MHz CPU, with 2 CPUs, each one with 12 cores. To resolve this issue: Calculate the maximum reservation value. For VPCs: 1 VPC equals 1 virtual CPU (vCPU); subject to the “lower of” rule above. Monitor this; if the application speed is OK, a higher threshold may be tolerated. 4Ghz per core and you assign one vCPU to a VM it. If workloads are CPU-intensive, the vCPU-to-core ratio will need to be smaller; if workloads are not CPU. Core,Logical CPU,vCPU Explained. If it matters, I am looking at vmWare for the virtualization implementation. So we will need 200GB of RAM to equal what we have in the physical boxes now. In older versions of VMware Workstation, the maximum CPU count was typically limited to 2 or 4 virtual CPUs per virtual machine. But some workloads – like SQL, for example – usually. Counter: usage ;. 1. Results: On the Physical Server, the entire application runs through its daily routine in about 90 minutes. A good rule of thumb is, when sizing your VM, if the CPU utilization in the guest is on average below 20% at all times, reduce the number of vCPUs. 00. This way, we have the four vCPUs pinned to physical cores and also using them in exclusivity, in the same NUMA. Next we need to calculate overhead for those VM’s…it comes to about 9. If you have HT off, you should turn it on. We install a first VM Windows Server 2019 act like DC with 2vcpu (1 socket) and a second VM for Veeam with 8vCPU (1 socket). Warning: If your virtual machine's. 2x vCPU VM should not be. 3x DL385G6 VMware cluster. If not known leave as Default. I am trying to understand vCPU concept in VMware. VMware uses the terms virtual CPU (vCPU) and physical CPU (pCPU) to distinguish between the processors within the VM and the underlying physical processor cores. PROCESSOR = CPU. When HT is NOT enabled, 1 vCPU = 1 physical. vmkernel runs always on physical core 0. . The old 8:1 ratio still applies in a server virtualisation scenario. CPU ready is a reliable metric to determine when or if you have truly overprovisioned your pCPU's. CPU usage is the average CPU utilization over all available virtual CPUs in the virtual machine. Host CPU Considerations. Total amount of CPU resources available in the cluster. Not all. SOCKET = Physical hole where in one Processor can fit in. ESXi Host CPU and CPU Overcommitment. I wouldn't hesitate to run 16 or even 32 VM's with single cores on a 8 core physical machine. and basing it on purely vCPU then 8 would be minimum but would give little room for moving machines around for patching ESXi, covering off high CPU workloads or providing resilience for potential hardware failures, I would recommend a minimum n+1 so 9 hosts. What hyperthreading does is present each core as two logical cores to your system. To calculate virtual machine CPUs within the vSphere Client, multiply the number of sockets selected by. However, this is not entirely correct, as the vCPU is made up of time slots across all available physical cores, so in general 1vCPU is actually more powerful than a single core, especially if the physical CPUs have 8 cores. 7. I'm looking for a quick wrap up on the best practices and the methodology behind how a vCPU (a virtual cpu given to a VM within the VM's property) maps to a physical CPU. It is possible to overcommit compute resources, you could potentially have VMs running on a host that between them have more virtual processor cores than you physically have available. • SQL Server running in a 2 vCPU virtual machine performed at 92 percent of a physical system booted with 2 CPUs. In vSphere, a physical CPU (pCPU)The VMkernel Resource Manager schedules the virtual CPUs on physical CPUs, thereby managing the virtual machine’s access to physical CPU resources. How does VMWare calculate CPU? To calculate the number of logical CPUs in vSphere Client, multiply the number of sockets by the number of cores. For CPU's it isn't a 1 to 1 ratio for physical to virtual. New CPUs (at least in the consumer market) will eventually likely all have the split into performance and efficient cores that Intel has started with the 12000 series. I am trying to find some documentation or best practice guides for virtualization with respect to provisioning vCPUs per physical core (of a CPU). Login to the vSphere Web Client and select the virtual machine in question. When a virtual machine is scheduled, its virtual processors are scheduled to run on physical processors. Also, it is important to mention that there is a limitation in the assignation of vCPU which is related to the license of the vSphere you are using. thanks to everyone !You can do this by configuring VM reservations and/or limiting host memory overcommitment. For RVUs: Use the License Information. CA requires an equal number of nodes in each fault domain. g. g. 0 GHz, then one vCPU assigned to a VM will be up to 2. For example, if a host has 128 logical CPUs, you can configure the virtual machine for 128 virtual CPUs. PROCESSOR = CPU. Does this seems correct? pCPU Calculation (# Processor Sockets) X (# Cores/Processor) = # Physical Processors (pCPU) 2 x 20 = 40 pCPU vCPU Calculation (# pCPU) X (2 threads/physical processor. Let me tell you why. A. Only ever use 1 Core per Socket, let vNUMA do it's thing. machines can be assigned to each CPU, or core, in the host. This is important when you overcommit vCPU/physical cores.