I am looking for articles or white papers that discuss the pros and
cons of Windows vs. UNIX clusters.

Dear deannadmb:

Thank you for your question. I have found quite a few straight Windows
NT versus UNIX based OS comparisons in my research, but most of these
only mention their clustering capabilities in passing. I've limited my
answer to those papers and articles that specifically deal with the
clustering capabilities of these two operating systems.

I have found one paper in the NEC research index [
http://citeseer.nj.nec.com/cs ] that studies specifically Windows NT,
Linux and QNX and their capabilities as cluster systems. Here is the
abstract:

"Abstract: Clusters use commodity hardware and software components to
provide an environment for parallel processing. A major issue in the
development of a cluster system is the choice of the operating system
that will run on each node. We compare three alternatives: Windows NT,
Linux, and QNX --- a real-time microkernel. The comparison is based on
expressive power, performance, and ease-of-use metrics. The result is
that none of these systems has a clear advantage over the others in
all the metrics..."

The paper is available in PDF format here:
http://citeseer.nj.nec.com/rd/92769265%2C430822%2C1%2C0.25%2CDownload/http%3AqSqqSqciteseer.nj.nec.comqSqcacheqSqpapersqSqcsqSq21938qSqhttp%3AzSzzSzwww.cs.huji.ac.ilzSz%7EfeitzSzpaperszSzbase.pdf/comparing-windows-nt-linux.pdf

There is a list of citations referenced the above paper here:
http://citeseer.nj.nec.com/430822.html

The next paper I have found studies the performance of fluid dynamics
computations (CFD) in four systems: two running UNIX, one running
RedHat Linux, and one running Windows NT 4.0. This paper is more of a
study on the servers than the OS, but you would find the graphs
helpful. The paper is available below:
http://www.hp-partners.com/fluent_public/clusters/whitepaper_overview.htm

There is a great article titled "NT versus Linux - Linux in the Lead" 
on hoise.com. The article deals specifically with their clustering
capabilities. Here is an excerpt:

"Installing Linux is easier than installing NT, when you need to do it
on for instance hundred computers in a cluster. You can use server
images, the tar and copy commands, the sed configuration file or make
use of convenient tools for installing systems from a vendor like SuSe
that has its SALT system. On NT it is more difficult. You have tools
like HD cloning, server images and merge facilities. But be aware,
wrong use of for instance WIN32 SID's can completely screw up your
systems."
http://www.hoise.com/primeur/00/articles/live/AE-PL-06-00-4.html

Finally, although the following article "NT vs Unix: Is One
Substantially Better?" does not deal specifically with clusters, it
does mention the clustering capabilities of both types of operating
systems in length. It's a rather long article, and is available here:

NT vs Unix: Is One Substantially Better?
http://www.winntmag.com/Articles/Index.cfm?ArticleID=4500&pg=1


Google Search Strategy:

Windows NT UNIX "NT clusters" OR "unix clusters" versus
Windows NT UNIX "NT clusters" OR "unix clusters" comparing
Windows NT UNIX "NT clusters" OR "unix clusters" comparison

I hope this helps!

Best Regards,
bladeer-ga

Sorry -- 5 stars aren't enough -- need to go to 9.5! I wasted more
time than I'm willing to admit trying to find info about this.
Needless to say, I will not hesitate (not even a nano-second) to use
your services in the future!