Auckland, NZ, 29 August 2007 - This paper attempts to address two questions:

(a) What is a blade server and why do we need it at all?
(b) What is state-of-art today?

A Blade Server is simply a multitude of server systems grouped together to share the same enclosure for attaining higher economies of scale.  Instead of having 10 slim systems mounted in a cabinet each with its own power supply and cabling, we can have them installed into a blade server enclosure and have only one set of everything instead of 10.  There will not be the same level of messy cabling- see picture below on the left.  A well designed blade server can reduce cabling by 70% and this implies a reduction of management cost by 70% as well.  Rack space is a premium in data centers ($45 of rent per month for 1U).  If we reduce the space for 10 slim systems from 10U to 7U, we would effectively reduce this rent every month.  There is of course an optimal limit to space reduction and we have possibly reached this by having 10 systems in the space of 7U.

Maintenance and management of server hardware is a big cost.  The blade server reduces this cost by providing centralized power supply, monitoring, networking and clustering arrangements.   These centralization tools do not take up extra rack space as they are integrated into the same blade server enclosure making the blade server very self-contained and identifiable.  The picture in the middle shows the rear of a SuperBlade Server by Compucon with 20 GbE ports, 10 Infiniband ports and an IPMI 2.0 based serial and KVM ports.

The blades in a blade server are stand-alone although they share physical assets such as the enclosure, power supply and centralization tools. Each blade, as shown in the picture on the right, has its own motherboard, chipset, CPU, memory, VGA, hard drives, Ethernet ports and Infiniband ports if applicable. We can have a mixture of blades based on Intel and AMD technologies; a caution to take note of though is that this concept applies to the SuperBlade by Compucon only and is not necessarily applicable to other older designs by other vendors.  There is no requirement to initially choose a particular platform (Intel or AMD) although blade servers themselves are a proprietary development and this implies that users of one brand are restrained to the same brand for blade modules.  For example, the current market leader takes 9U for a 10 blade server whereas the SuperBlade by Compucon takes 7U.  The blades are obviously not interchangeable between the two brands based on form factor and interface specifications.  We may find that SuperBlades are higher in specification and lower in cost but users cannot buy SuperBlade modules for other brands of blade servers.  It is therefore important that users carefully consider this issue of involuntary brand loyalty earlier in the planning stage.

Blade Server technology is very much for space optimization and economies of scale.  In the pursuit of space optimization, some blade servers accept 2.5" laptop-size hard drives only and this will increase hardware costs.  SuperBlade also provides the option for 2 drives in 3.5" form factor to keep costs down and to allow for the maximum capacity per blade (up to 1TB per drive).  To summarize, the state of the art blade server optimizes cabinet space, reduces management and maintenance cost, provides platform choices and maximum computing and storage capacities.