ESXi 4 outperforming Esxi 5

Posted on 2012-09-21
Last Modified: 2014-09-07

I'm a little stumped. I've to two hosts one is vsphere 5 enterprise plus and the other is vsphere 4 advanced.

I use these hosts to run a citrix workload. The other day I noticed that the execution time of a cpu intensive task on the version 5 host was taking 2 times longer to run that on the verison 4 hosts.

After some testing I can see that the application is hitting a single core and that the amount of time to process the same transaction between servers is 2:20 on v4 and 4:20 on v5.

I've ruled out the build of the citrix server by migrating one from v4 to v5 and the longer result occures.

So the only differences I can see is that the citrix servers have hardware version 7 on the v4 host and version 8 on the v5 server.

I'm 99% sure it's a cpu thing, it makes no difference if there are other users on the system during testing the results are the same as with no users on the system.

V4 physical
vsphere 4v5 physical
The application is running some basic type scripts which is looping and processing some data in memory and I notice that the memory for the process increases by about 100mb during the processing... it's just that the v4 server does this cpu intensive task much faster than v5...

And yes I have checked everything the network/config of guests the lot.

I'm stumped?
Question by:APNFSSC
    LVL 42

    Assisted Solution

    Try reserving the memory for the citrix servers, we've found that it helps execution time since vmware shares memory and citrix needs to spool up quickly depending on load.

    What version are your datastores?  With vSphere 5 you should be using updated datastores, if you upgraded from VMFS 3.x versus creating a new datastore then it's running in mixed mode, I would try creating a new VMFS 5 datastore and executing the VM from there.
    LVL 10

    Author Comment


    The esxi v5 hosts were clean builds so the vmfs filesystem should be fine.

    None of the guests have reservations on any host. I have added reservations and it hasnt improved the speeds.

    LVL 116

    Expert Comment

    by:Andrew Hancock (VMware vExpert / EE MVE)
    I think this is one, for VMware Support!
    LVL 10

    Author Comment

    yeah I'm thinking so... there isnt a known issue with this that I can find. whats funny is if I run a cpu benchmark utility on both v4 and v5 from within a guest they benchmark close to the same.

    We have basic support ... I'm not sure how helpful they will be.
    LVL 10

    Accepted Solution

    End result on these was a bios setting that was limiting the cpu .... bios setting altered and performance resolved.
    LVL 10

    Author Closing Comment

    Thanks for the holp

    Featured Post

    Do You Know the 4 Main Threat Actor Types?

    Do you know the main threat actor types? Most attackers fall into one of four categories, each with their own favored tactics, techniques, and procedures.

    Join & Write a Comment

    One of the new features of a version 7.0 or later virtual machine, supported in VMware vSphere 4.1, 5.0 or the VMware vSphere Hypervisor ESXi 4.1, ESXi 5.0 often overlooked by VMware Administrators is the ability to add and connect USB devices conne…
    David Varnum recently wrote up his impressions of PRTG, based on a presentation by my colleague Christian at Tech Field Day at VMworld in Barcelona. Thanks David, for your detailed and honest evaluation!
    Teach the user how to configure vSphere clusters to support the VMware FT feature Open vSphere Web Client: Verify vSphere HA is enabled: Verify netowrking for vMotion and FT Logging is in place or create it: Turn On FT for a virtual machine: Verify …
    How to install and configure Citrix XenApp 6.5 - Part 1. In this video tutorial we have explained step by step installation of Citrix XenApp 6.5 Server on Windows Server 2008 R2 is explained in this video. We have explained the difference between…

    729 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    22 Experts available now in Live!

    Get 1:1 Help Now