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This is a blog for John Weber. One of my joys in life is helping others get ahead in life. Content here will be focused on that from this date forward. John was a Skype for Business MVP (2015-2018) - before that, a Lync Server MVP (2010-2014). I used to write a variety of articles (https://tsoorad.blogspot.com) on technical issues with a smattering of other interests. I have a variety of certifications dating back to Novell CNE and working up through the Microsoft MCP stack to MCITP multiple times. FWIW, I am on my third career - ex-USMC, retired US Army. I have a fancy MBA. The opinions expressed on this blog are mine and mine alone.


VMWare & AMD dual core cpu clocks

With the growing wave and industry push to virtualize, and my recent (unpleasant) experience with vmware workstation and AMD dual core CPU's, I thought would put together a few observations.

1.  This problem did NOT exist under VPC or VS2005r2.  Don't know why; same host hardware, same RAM, same CPU, same host OS build.  But, it sure did not happen.

2.  The problem existed with VMWare Workstation 6.0.2, and it also happened under v5 and v6.0.

3.  CPU is AMD Turion x64.  From reading the internet, it also occurs with Athlon x64 and Opteron.  The AMD website has drivers for the Phenom series, so I assume that the issue exists with their new chips.

4.  Symptoms are that the guest OS runs the clock at least 300% faster than the host clock. 

a. This is caused by the host OS not handling the CPU TSC (time stamp counter) correctly. 

b. This is a Windows thing. 

c.  The issue is all about the hardware and the OS.  Empirically, Windows handles Intel chips  differently than the AMD chips.

5.  There are a variety of suggestions: here is what worked for me.

First make sure that global config.ini for vmware has the following contents:

This file is USUALLY located:  "c:\documents and settings\all users\application data\vmware\vmware workstation" - it will be different for a Vista host.

The first line is the rating of your cpu in gHz.  Mine is a 2.0, but the host reports it as 1994mHz.

host.cpukHz = "1994000"
host.noTSC = "TRUE"
ptsc.noTSC = "TRUE"
host.TSC.noForceSync = "TRUE"
prefvmx.useRecommendedLockedMemSize = "TRUE"

a.  http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182,00.html

Each AMD cpu has an "updates, drivers, & utilities" section.  Each one appears to be a tad different.

This driver is seriously needed just so that Windows and *nix (certain kernel levels) know how to handle the cpu. 

In my case, this was the first step - a side note - it sped up my host system by about 10-15% - or so it seems.

b.  Windows MS KB 896256 and  the AMD Dual-Core Optimizer. In theory, the MSKB does the same thing, but it only made things better, it did not FIX IT.  The installation of the AMD tool onto the host is what fixed things.  I have both installed on the host.

c.  Random observations - my XP guest detected an AMD driver update when I did all the updates.  The ws03 and ws08 updates did not find this.  And, as you may have guessed, this little update did not help anything.  Installing the AMD cpu driver into the guest did absolutely nothing to help things.

1 comment:

Unknown said...

I have athlon X2 5600+ and had a month of running my virtual machines ok. Today, however, I was astonished to learn that my cpu clock is recognized by vmware as 48Ghz cpu!!! And I did absolutely nothing to cause this! My vm's were running terribly slow. But thanks to this page I created the proper config.ini, which solved my problem!

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