I must say I really love the blade concept, not so much by the annoying "data center cost saving" hype. I strongly doubt that 10 Xeon blades use much less power than 10 1U Xeon servers.
Power wise, the enclosure wants 4 16 Amp 3-pole plugs.. go figure :)
No, what I really like about blade servers is the ease of management and administration. The Dell Blade enclosures we got has 2 built in switch modules, DRAC/MC card and the optional IP-over-KVM module. All these cool modules are cheap so I can't imagine anyone ordering a blade enclosure without them.
Then we have the cable side of things. Each enclosure holds 10 servers, from the enclosure we have:
Thats 7 in total, compare to 10 1U servers:
Thats 80!! in total. Or about 180 meters of cables. Dang! If we would have had fibre-channel connectivity we would have saved another 18 cables.
Ok, now to what really counts. Price!
For us it started making sense after about 4-5 servers, thas just silly. The question was more "why not" to buy blades. Each blade came in at about £1350 (dual 3.2Ghz, 4Gb, 2x146Gb) and the enclosure itself was about a silly £1000 (including the modules). Thats £15000 for 10 machines, a similar speced PE 1850 costs about £1600. Not that much of saving you say, a lousy £1000 for 10 machines.
But look at the extra costs around having 10 servers, take the 10 slots on a KVM switch, take the 18 extra ports in ethernet switches, take the freakin' cables. I'm assuming a cost of £1200 for a 16 port KVM switch, allocating 10 of those costs £750, 18 switch ports in two switches at £500 each is £416, 28 cat5 cables at perhaps 60 pounds for a pack.
I'm not counting the extra allocation of PDU's due to the fact the blade enclosure uses the previously mentioned 16A 3-pole sockets which of you probably have to have a few extra installed.
Now we have a cost saving of about £2260 per enclosure.
The biggest saving however will be in time, I'll blog about the ease of use another day. Funny enough the blades will be installed with a huge mix of opterating systems. Windows, both 2000 server and 2003 server, alongside Centos 3, Centos 4 and Solaris 10. Most of them running Weblogic, Websphere and Jboss.
And a small PS. Nooo, I could not have bought Opterons nor the new Conroe procs. These machines are going to be used mainly for application support mimicking customer environments. And as most people probably know, investment banks don't mix with the latest technology.