Vmxnet3 10gb performance. 7 installed on Dell PowerEdge R640 server with 10GB nic (2x 1GB + 2x 10GB). There is an ongoing debate between many admins on what are the best settings for the VMXNET3 driver on Windows 2008 R2 settings and I suppose there will be many more. Using iperf3 between clients on the same VMware host for testing, same… Unless you have the situation you talk about next… 2nd question: I believe so. 4) each with dual 10Gb Intel NICs. The 10Gb vmxnet3 gives me a VM to host networking performance of more than 230Mb/s. 2 and above, virtual NICs configured with VMXNET3 can operate between 10 Gbps and 65 Gbps, offering a significant boost in data plane performance. XPEnology is great. As with an earlier post we addressed Windows Server 2012 R2 but, with 20… I've tried e1000e, e1000, and vmxnet3 virtual network cards, all of them has this problem. VMXNET3 is much faster than e1000 or e1000e. 5, including support for jumbo frames and TSO for Enhanced VMXNET devices. I have kept it simple and kept FreeNAS and a CentOS 7 VM on the same host to take any issues with switches and cabling out of the picture. It has an iSCSI data store connected 1. Running latest pfSense in VMware with the VMXNET3 NIC. Drivers are shipped with the VMware tools and most OS are supported. VMXNET 3 offers jumbo frames, multiqueue support (Receive Side Scaling in Windows), IPv6 offloads, and MSI/MSI-X interrupt delivery. May 28, 2025 · With vSphere 8. VMXNET 3 (Best) Next-gen paravirtualized NIC (10Gb), designed for performance Not related to VMXNET/VMXNET 2 All the features of VMXNET 2, plus several new features multiqueue support a. I shut the VM down, removed the E1000 put in a new network with vmxnet3 and again got horrible performance. Using iperf3 between clients on the same VMware host for testing, same… The model of this particular 10GB adapter is the Intel X540-AT2, we are running the same card in all 4 of our hosts. Still very happy with all the hard work everyone is doing. Server is conected to d’link switch witch 10GB ports. I believe that some versions of the Windows VMXNET3 driver also allow for dynamic sizing of the RX buffer based on load. 0. Mar 4, 2024 · You can try VMXnet3 without VMQ, which should run much better and would also confirm my suspicions. VMXNET 3 is a paravirtualized NIC designed for performance. I tested each virtual network adapter type offered in the Proxmox interface: VirtIO, E1000, Realtek RTL8139, and VMWare vmxnet3. I can't remember what version of ESXi is affected though. The VM is a backup server with two 10gig VMXNET3 NICs connected to a vSwitch with two 10gig Qlogic NICs One VM NIC talks to at tape server, the other one to a QNAP via iSCSI. When i do iperf3 when client is sending, cant get more than 4Gbit/s but if VirtIO NIC checksum fail & poor speed Hey all, I have a 3 node cluster (6. Receive Side Scaling (Windows) IPv6 offloads MSI/MSI-X interrupt delivery Faster than e1000 (e), less CPU overhead Read more about VMware VNICS. 5 and later. Jun 19, 2025 · By default, VMware’s VMXNET3 virtual NIC reports a 10 Gbps link inside the guest OS—even when your physical network can handle more. I used Ubuntu x64 with vmware tools installed. 0-RELEASE FreeBSD 12. What version of VMware Tools are your VMs running specifically? Hi, I am trying to get virtio network driver working using in a VM in KVM, as the e1000e network driver (which is working) gives very bad performance. x. Slow VMXNET3 performance on 10gig connection 14 votes, 17 comments. If vmxnet3 will not hinder performance (after switch to update 2 and disable LRO at host level) and provide some auxilliary gain, perfect, at some point I'll find a real use for the latest & greatest. I tried disabling Kernel PTI mitigations, disabling network card offloading, raising the queues on the For best performance, use VMXNET 3 type of adapters which is the current default in vSphere 7. 5 A number of enhancements have been integrated into the networking code of ESX 3. Performance Enhancements in ESX 3. I am using IG-88's driver extension (extra. But im running into slow performance issues connecting to the same SAN over the same network from inside a VM Guest using Windows 7 and the VMXNET3 adaptor. On both Windows and CentOS 7. I have zero issues with Windows. Mar 4, 2025 · The default link speed of a vmxnet3 adapter is 10Gbps as shown on the screenshot below. I tried disabling Kernel PTI mitigations, disabling network card offloading, raising the queues on the VMWare VM Server Tuning – Windows OS & VMXNet3 Network Card Optimizations In Windows, Open a command prompt window with elevated permissions and execute the following commands displayed in RED. For an ESX (i) host with multiple uplinks from its vSwitch, a VMXNET3 may help a lot. a. However, some guest operating systems or applications may not fully utilize this speed or may misinterpret it, causing suboptimal performance. Whatever the outcome, many thanks for what you've achieved thus far ! 24H2 Windows 11 and Server 2025 VMXnet3 Issues Many people reported performance issues with 24H2 MS Operating Systems in VMWare. There also seems to be The default link speed of a vmxnet3 adapter is 10Gbps as shown on the screenshot below. Installed 10GB nic in ESXI host and switched all VM's to VMXNET3 nic and windows will show it as 10GB but using iperf to test connections it maxes out a 4GB. VirtIO was giving me about 2. I'm using bridged networking so that VMs can grab IP directly off my router, NAT ("shared with my Mac") does not have this issue. None of the other network adapter types were even able to achieve 1Gbps. lzma), but can't get it working. x VM's I have VirtIO 10Gb networking installed. I'm having a problem where pfSense on ESXi 7u2 can't push more than half a gigabit through using VMXNET3 adapters inside pfSense with 4 vCPUs, but I can't get gigabit speeds. 0-RELEASE r341666 GENERIC amd64 Working as a quest on esxi 6. Introduction In this post we will cover an updated version for addressing VMXNET3 performance issues on Windows Server 2016. Unfortunetly copying 10GB file i get max 300 MB IIRC, there was an issue with VMXNET3 adapters and Receive Side Coalescing and Receive Side Scaling which could potentially cause performance issues. Same thing goes for an old windows7 vm with RSS activated. VMXNET 2 (Enhanced) is available only for some guest operating systems on ESX/ ESXi 3. VMXNET 3 offers all the features available in VMXNET 2 and Hi buddies,The upper limit of vmxnet3 is 10GB in practice? if vmware can support higher performance?Thanks in advance. I have also a PC with 10GB nic (Aquantia AQC107) connected to the same switch. While testing, it seems that offloading and power management features in 24H2 caused the performance drops, and adjusting those settings in Windows I removed the VMXnet3 and put in an E1000 and performance was exactly as expected. May 28, 2025 · In VMware vSphere 8. I have also tried updating the vmware driver for this NIC with no noticeable gain in performance. The Junipers are configured for jumbo frames VM: Windows 2019, patched VMXNET adapter, DirectPath IO disabled WIndows networking: no jumbo frames (1514 frame size) large send offload enabled checksum offload enabled (basically default settings) The VMXNET 3 Virtual NIC is a completely virtualised 10GB paravirtualised NIC designed for performance. In order to get the best network performance between my virtual servers I will replace the NICs with the new VMXNET3 adapter, which supports speeds of up to 10Gbps. 2 and later, the default link speed for the vmxnet3 virtual network adapter is 10 Gbps. This is what I have done. This discrepancy can impact diagnostics, in-guest backup, and performance tools that rely on reported link speed. VMXNET 3 A paravirtualized NIC designed for performance. 14 votes, 17 comments. I also noticed when adding this NIC to monitoring in PRTG it shows as only a 4GB connection. The ethtool command is useful for determining the current ring sizes in most Linux distros: This is normal for any connection above 10gb with vmxnet3. On CentOS I find that any files that are moved to/from a network share fail checksum. In this postI will attempt to … VMXNET 2 (Enhanced) Based on the VMXNET adapter but provides high-performance features commonly used on modern networks, such as jumbo frames and hardware offloads. k. This article provides steps to change the vmxnet3 link speed of a VM. Jumbo frames are large Ethernet frames, typically 9000 bytes, which are larger than the standard Ethernet MTU (maximum transfer unit) of 1500 bytes. The VMXNET3 adapter is the next generation of Para virtualized NIC designed for performance. Aug 1, 2025 · Issue/Introduction The default link speed of a vmxnet3 adapter is 10Gbps. But, without VMQ or SR-IOV, you can't really utilize a 10G or even faster vNIC. Guest operating systems using jumbo frames need fewer VMXnet3 is a paravirtual adapter that does not emulate specific physical hardware, but is software only - and software speed limited only. The 82574L is cool, but is it faster than an VMXNET3? What’s VMXNET3? The VMXNET3 adapter is the next generation of Para virtualized NIC designed for performance. The VMXNET3 network adapter is a 10Gb virtual NIC. The default does vary from OS to OS and can also vary depending on the VMXNET3 driver version being utilized. 5 and have found that 10Gbe networking to be poor. In this post I want to show how we can change the vmxnet3 link speed of a virtual machine. Hello all, I’m using VMWare ESXi free 6. Receive Side Scaling (Windows) IPv6 offloads MSI/MSI-X interrupt delivery Faster than e1000 (e), less CPU overhead Read more about VMware VNICS Hi all, I have been doing some testing with iperf3 and FreeNAS running as a VM in ESXi 6. Config: ESX using 2x 10GBe NIC's via Vswitch over iSCSI to SAN with 2x10Gbe NICs Guest VM OS drive is on the data store that is on the SAN over ISCSI Performance on C drive is 800-1000MB/s VMXNET 3 (Best) Next-gen paravirtualized NIC (10Gb), designed for performance Not related to VMXNET/VMXNET 2 All the features of VMXNET 2, plus several new features multiqueue support a. virtIO is paravirtualized as well. Slow VMXNET3 performance on 10gig connection billybobSSD Feb 27, 2012 06:41 PM I have an ESXi server with an Intel X520-DA2 10 gig adapter in it. I don’t believe it is possible to change the adapter type for existing network adapters so I have removed the E1000 adapters and replaced them with new VMXNET3 adapters. It’s just a limitation of what it will display, but it is running at full speed. On ESXi I created VM - Windows 10 with vmxnet3 nic and on a PC created 12GB ramdisk for tests. A VMXNET3 is presented to the VM as a 10Gb adapter, as such, it'll pass more than 1Gb of traffic to a VM. Everything is I'm having a problem where pfSense on ESXi 7u2 can't push more than half a gigabit through using VMXNET3 adapters inside pfSense with 4 vCPUs, but I can't get gigabit speeds. 5Gbps. The VMXNET3 adapter is the next generation of Paravirtualized NIC designed for performance. VMXNET3 has less CPU overhead compared to e1000 or e1000e. Switching the network from VMXnet3 to E1000 would fix the issue, but drop the network from the 10GB to 1GB bandwidth. I added in 'virtio, virtio_ring and virtio_n Hey guys, I have Freebsd 12. 7 with hardware Dell R330, 16Gb DDR4, Xeon E3-1235L v5, Chelsio T520-SO No other vm/quests in this machine. Click to expand the interface options and ensure it’s set to VMXNET 3. Out of the box with no performance tuning, VirtIO actually performed the best for me by far. Troubleshooting poor VMXNET3 10gbps performance Hi, I’m having some issues with a Server 2019 VM and I’m really struggling. VMWare VM Server Tuning – Windows OS & VMXNet3 Network Card Optimizations In Windows, Open a command prompt window with elevated permissions and execute the following commands displayed in RED. Only half. armi1, tfpvz, habtw, qaxxsu, kjr4l, s0dr, cpnb, ps3f9, w0vo, jgymdp,