Let me be the judge then.
For a site serving 13 million pageviews per month (80% of them are uncachable searches) we use 2 servers with about the same configuration (same memory, cpus). The database server has an average load of 1 and the application server (that is serving a bunch of other sites as well) is under 2 most of the day.
We have 1/2 of their capacity running an equally heavy site (all sites running on those servers make up 16-18 million pageviews per month). So if they run on 1/10 of similar sites, we run on 1/2 of their 1/10. Even better we pay 100% percent less of what they are paying. I wonder how smart Atwood is.
I don't intend to be a smart ass here. I would never say "Hey we run with 1/10 of your capacity, you are stupid" because performance heavily depends on the application. StackOverflow probably has a 90% cache hit ratio (86% of visitors are from google that land on some question asked some days or months ago). So 3 servers for a cache and forget site (logins and bits for pages that change often can be cached too) serving 16M pageviews per month is below average. They maybe doing a whole lot of other things in the backend that we don't know of , but the same goes for the other sites that "their programmers are stupid and use 10x hardware."
I would expect them to say what problems they solved and how instead of bragging about how awesome programmers they (he?) are.
do indent to be a smart ass.
I also believe that StackOverflow is great. I tried contributing but almost always someone hits submit before I do so I gave up until I have more free time.
Sorry for not being politically correct, I thought this was HN.
For a fair analysis, you need to consider that people keep adding answers and comments to questions, specially if it is covering an interesting question or technology. (And what happens to the cache then?)
Compare this to a more mainstream consumer website, say FriendFeed, which is currently on roughly the same scale as Stack Overflow. FriendFeed's business model is more "swing for the bleachers" and success would mean scaling to the size of Twitter. They need an architecture that can handle fast growth if it comes.
Stack Overflow is a much less risky proposition. They had excellent knowledge of the market, knew they could pull all the traffic from expertsexchange almost overnight, and they knew that scaling to tens of millions of monthly visitors was something they needed to worry about.
11K probably "cost" them less then the time and effort to come up to speed on open source solutions. They were MS experts already and it would have taken quite a bit to reach the same level of expertise in *nix land.
If you're young and just starting out and are wondering if you should become an expert in free or commercial software, keep their situation in mind.
... which is very similar to what my sites are doing (we do more than 20m page views w/ about the same # of uniques. Our content is very image heavy, though maybe a little more amenable to caching.
StackOverflow is running on 2 quad-core 8GB boxes and one 8-core 48GB db box. We're keeping up with VPS "slices" at SliceHost that add up to less than two full 4-core 16GB standard SliceHost boxes; and I expect to reduce capacity when I finish moving our image assets off to S3+CDN.
We have one full time developer/sysadmin/etc.: me. Are other similarly trafficked sites really using a lot more iron? I thought we were typical for this scale.
I'd be much more interested in knowing about the internal architecture of the software running the site rather than just "they threw this server together with that one and then v1.2.3 of this other one too".
Congratulations, you just implemented your key/value store in MSSQL.
I thought I was on thedailywtf for a second there. So they took Oracle, and implemented an RDBMS in it?
Seriously, the hardware they have has a lot of room for growth.
They make it sound like that's a good thing. It is not.
Show that to any halfway competent SQL guy and you'll get a disgusted response. Implementing a database on top of an existing RDBMs is an antipattern.
How in are they going to get 'shared' hosting working with such a silo-ed vertical setup? Are they going to be assigning customer sites to machines ala Dreamhost et. al.?
Will they end up paying for separate Windows Server and SQL Server licenses to run each 'dedicated' site in its own VM? Are they going to be manually migrating customers who exceed the size of what they can handle in one VM?