Brains Count, Speed Matters

CPU socket counts are likely to stay relatively low as logical core counts rise and the amount of RAM burgeons in the data center servers of tomorrow. A wave of virtualization that started around 2006 is still building strength as the number of virtual servers continues to increase. At the same time, virtualization is pushing up the capacity of physical data center servers.

According to Malcolm Ferguson, enterprise solution architect at HP, typical rack-mount and blade-server configurations are changing. "These servers had [in 2006] an average of 4GB of RAM where today they can have 200GB RAM, on average." And some current server designs can accommodate 256GB or even 1TB of RAM. And according to Ferguson, RAM requirements, especially for virtual machines, have jumped. "It was common for applications to specify from 2 to 4GB of RAM before the wide-scale adoption of virtualization. Now, it's not uncommon to see 24, 48, 96GB of RAM specified for single servers."

The increasing RAM use has caused much of the concern in VMware's changed licensing procedures. The so-called "RAM tax" in VMware's initial vSphere 5.0 license revision created a license fee based on the amount of vRAM allocated among virtual machines (which might be less than the total amount of physical RAM installed.) VMware reacted to user concerns and modified the initial license terms, while retaining the basic premise of using vRAM allocation as the basis for license fees. It remains to be seen how this non-technical aspect of server virtualization will affect physical server configurations of the future.