I did a quick search and didnt find any info on this. I have a Dell Poweredge 2950 and the BIOS does say that Hyper Threading is active and the ESX 3.0.1 server console states that it is enabled but is inactive. I thought it was as simple as enableing the VM enhancements in the BIOs but that doesnt appear to be it. Any suggestions?
Thanks,
Anthony
2950s ship either with dual core Xeon 51xx or quad core Xeon 53xx series processors; none of these have Hyperthreading available. Hence no BIOS switch as well.
More details on processor features availabe on Intel's website at:
http://www.intel.com/products/processor_number/chart/xeon.htm
Did you reboot the host after you applied the Hyper threading setting in processor properties?
We are a Dell shop, and I can tell you that 2950's do not have a hyperthreading option in the BIOS. They do have a VT option, however, which is disabled by defualt and you should turn on for ESX usage. With the Dell 2950, you need to disable hyperthreading in the ESX software itself.
2950s ship either with dual core Xeon 51xx or quad core Xeon 53xx series processors; none of these have Hyperthreading available. Hence no BIOS switch as well.
More details on processor features availabe on Intel's website at:
http://www.intel.com/products/processor_number/chart/xeon.htm
Yep the server has been bounced a couple of times.
Thanks for all the replies. I have figured out based on the responces that Hyper-Threading is not supported in the 2950...kind of odd but oh well.
A.
Not trying to add too much confusion to this thread but early Dell 1950's and 2950's did come with processors with hyperthreading. Those were the Intel 5000 series Xeons. The switch for us to the 5100's occurred around 8/1/2006.
Yes, it's not that the Dell server doesn't support HT, is that's Core2-based Xeons don't support (nor need) hyperthreading.
Thread has been dead for a while, but had a question about this.
Would there be any performance gain by turning off the Hyperthreading in Processors Configuration? Does iy make any diffrence on or off on a 2950?
Want to try and figure out how quickly I should get our Hosts rebooted now that have disabled the option.
Cheers
our is one that has the option. things are going slow so i'm going to turn it off and see if things improve.
I reckon things will slow down even more. VMware sees every thread as a way of additional processing, so best to leave HyperT enabled.
Enabling HT or not really depends on what kind of shop you have. From what I've seen windows machines only get a 10-15% boost from it and *nix machines are even worse with 1-2% increase (no refs on those numbers, this is just what I've experienced). If you are primarily a *nix shop, I'd suggest you disable it altogether. For windows, make sure you don't have processes that depend on each other to finish in the VM or you will be wasting cycles. The good news though is ESX is smart enough to schedule the "real" procs first for clients (i.e. a two proc VM will be scheduled on two seperate cores) and won't use HT unless it absolutely has to.
As always, test, test, test, test, test, and see what works best for you!
Oh, btw, try to stay away from making any four proc VMs for the time being as much as possible. Unless you have a very well tuned host or cluster, it's a bad idea.