> 
> As for the ISA, Intel seems to be very "ad hoc" compared to the z
> architecture. Especially in the virtualization arena. Basically, the z has a
> _single_ virtualization instruction: SIE. Intel has I don't know how many
> different versions of different instructions to let hypervisors run at all. I 
> don't
> know how efficient vitualization actually is on Intel. But it wouldn't 
> surprise
> me if it were a pig.
> 

Having run a medium sized organization with 30 physical servers and 300 or so 
virtual windows images I would say Intel virtualization via a bare metal 
hypervisor, such as VMWare is pretty efficient. Also whilst you only have SIE 
there are (or were when I was actively involved) several levels of SIE Assist, 
just there are various levels of VT on Intel. The Microsoft stuff is less 
efficient as it uses a thin windows structure which uses more resources. 

The problem with it is the back end storage, you need to put a lot of effort in 
getting storage that can deliver the IOPS and low latency you need for a quick 
database. I am so glad I no longer have to keep telling my manager that the 
reason the storage is slow is because he has bought cheap disks, and instead of 
managing for IO performance they formatted RAID6 for capacity and of course 
when the SQL log backups kick in at lunch time the world goes pear shaped. 



> --
> If you sent twitter messages while exploring, are you on a textpedition?
> 
> He's about as useful as a wax frying pan.
> 
> 10 to the 12th power microphones = 1 Megaphone
> 
> Maranatha! <><
> John McKown

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