Unix vs. NT

"Unix vs. Windows NT" (May cover story) was very well done and informative. However, you overlooked Linux, which definitely has potential in many organiza tions and is a more cost-effective OS for the x86 platform than Windows NT.

John Iliff
Pinellas Park Public Library
Pinellas Park, FL
http://pppl.tblc.lib.fl.us

It was not possible to consider all the flavors of Unix. I tried to keep my discussion generic, focusing on Sun in a few cases because of its status as a primary flag-bearer. Linux could be a good solution for some installations, but other businesses might be reluctant to adopt a Unix that is perhaps not as well supported by a single vendor as other variants, such as Solaris, AIX, or HP-UX. Some MIS directors want that "big business" relationship with their vendors. It costs more, but it makes them feel more comfortable.--Tom R. Halfhill, senior editor

In the article on Unix vs. NT, you say, "Architectural limitations hobble low-priced x86-based servers when they try to tackle the really big jobs." Most of the rest of the article suggests that the reason x86 boxes running NT cannot keep up with Unix boxes is they do not have enough processor power, but that this can be fixed by improving NT's symmetric multiprocessing (SMP) scalability. I disagree. Benchmarks we performed in 1995 showed that NT experiences an I/O bottleneck long before it runs out of processor throughput.

Jonathan Handler
71702.1620@compuserve.com

I was talking about much more than CPU power--indeed, the Pentium Pro holds its own with the fastest RISC chips i n terms of integer performance. The main limitations are system architectures and the inability of NT to scale linearly beyond six or eight processors in an SMP system. Unix is more scalable in this regard, and Unix servers tend to be built on superior system architectures that deliver higher overall performance. Of course, they usually cost a lot more, too.

In this issue of BYTE, we analyze two new server architectures that attempt to address this problem (see "The Network Inside the Server," page 151). One of them, Sequent's NUMA-Q, is based on the Pentium Pro and supports both a Unix variant (DYNIX/ptx) and NT.--Tom R. Halfhill