> From: Mag Gam [mailto:magaw...@gmail.com] > Sent: Thursday, December 11, 2008 10:33 PM > Subject: server upgrade question > > At my university we have 10 servers. Each server has 8 cores with 32 > GIG of memory running Debian 4.0. We have to give these servers to a > different department, and our Dean would like to consiladate 10 > servers into 5 servers. The new server will have 16 cores with 64 GIG > of memory. Basically a 2:1 type of deal. > > Since we are doing a 2:1, should we expect 2:1 performance? For > instance, most of our applications are heavy compute and memory > intensive applications. Would they run at the same speed, better, or > worse with this new setup? My guess is that same? > > Oh, yeah will be running 4.0 :-) > > TIA
It really depends. If your applications talk to each other a lot, chances are you will see an increase in speed when they don't have to go out to the LAN. You say your applications are Memory intensive and this will probably have the biggest impact. If the application is greedy and just uses all of the memory it can get its hands on, then you will probably see a decrease in performance as the instances of the applications will fight. If the application uses a set amount of memory (eg 2GB) and just constantly read/writes to that portion, then you probably won't notice a difference. When dealing with applications across multiple systems/cores it is very important to determine exactly what your overhead and constraints are first before trying to "upgrade" the system. A good example is a cluster I worked on a few years ago. It started out as five P3 500Mhz boxes. When we upgraded to fifteen Athlon 1.2Ghz systems, our application slowed to a crawl. The cross-talk on the LAN connection was killing the app. We temporarily configured just 2 of the Athlon systems and got better performance then either of the previous configurations while we recoded the app to better deal with scalability. If you can identify where the applications bottlenecks and strengths are, you will be in a much better position to know how hardware upgrades will affect your results. Have fun! ~S~ -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
