On Jan 6, 2009, at 3:56 AM, Derek Pappas wrote:
Our company looked at the cost of moving data in and out of the cloud
for our application and concluded that it was prohibitive. Instead we
use a co-lo which costs $850/month (15AMPS (assume 1.5 amps/server,
20mbs). We hammer on the internet connect keeping it pegged at 20mbs.
We also store a lot of data. So we ruled out EC2 and built a small
cluster
with a lot of 1TB drives.
One option is to buy 1U servers that are a couple of years old.
You can pick up dual Xeon Dell 850's for ~$250 if you look around.
These have SATA controllers and you can buy Seagate 1TB drives
from Frys or Newegg for ~$100.
Your $850/month colo cost is fantastically cheap (if it's a full
cabinet)! Ours costs about that much for *space* only. In addition to
that, our colo charges roughly $300 per 20 amp circuit (15 amps
usable), which means you really need 4x20 amp circuits to actually use
up all 40 Us of space, so we're really talking $2k per month. However,
we hit heat issues well before filling up 40 U of space. Some colos
will limit you to 2x20 amp circuits per cabinet because they don't
have the cooling capacity.
(These figures are for a fancy colo facility in Manhattan.)
Well, suppose that you could fill up the entire cabinet. That means
you're getting 40 servers at about $2k/month, which runs you $50/
month. In contrast, AWS large instances are a bit less than $300/
month, so yes you're coming out ahead. Dedicated server rentals could
be about $200/month for machines that powerful (based on
serverbeach.com's prices), so you can reach an intermediate price
point without having to commit to a colo.
Also:
If you purchase a new computer at $2500, ran it for 4 years, then sold
it for $500, you'd end up paying about $52/month, roughly the cost of
the colo per U.
If you purchase a 4 year old computer at $500 and ran it for 4 years,
that'd come to $10/month. However, if computer speeds double every two
years, you're effective cost relative to the new purchase is more like
$40/month for CPU intensive applications. Ie, you need 4 x 4 year old
machines to match 1 new machine in computing power.
If you lease a machine and change it every 2 years, you pay something
in between those two amounts, however I don't recall our lease rates
or arrangements.
In my opinion, if leasing is an option, it seems to be a pretty nice
sweet spot: roughly the same cost, and you always have nice fast
hardware.
But I'd like to point out that in the long run, the cost of computing
resources is roughly constant, but space+electricity+cooling is
becoming more expensive, and at the moment, they're roughly equivalent
assuming a 3 or 4 year lifetime for hardware. It makes sense, then, to
minimize the amount of space+power you use, since those will probably
become the dominant cost.
And one last note: none of this is taking into account staff time
required to handle colo responsibilities, such as racking, and
debugging/replacing faulty hardware.
Wes
