From uni to multi
We are moving from Online 5.0x to IDS 9.2x. Our applications are all single-threaded. What can be gained, and how much if a second CPU is added and we make no changes in our apps ? Thansk, Thanh Sent via Deja.com http://www.deja.com/ Before you buy.
Thanh wrote: > > We are moving from Online 5.0x to IDS 9.2x. > Our applications are all single-threaded. What can be gained, > and how much if a second CPU is added and we make no changes > in our apps ? Don't be too hard on the Clown, the nose obstructs his view. I think his point was that we need more info on the app and database to really be able to help. Anyway here is what I can give up on the limited info you provided. In general IDS 7.xx/8.xx/9.xx takes very good advantage of three or more processors to perform work for single queries in parallel, only two CPUs, the benefits are not as great though it has to help. A horse runs faster on two sets of legs than I can on one (OK with my injury I cannot run at all, but that doesn't count ;-). OL5.xx does not do ANY parallelization EXCEPT parallel sorting which requires the overhead of starting multiple sqlturbo's, all IDS 7/8/9 tasking is using threads in active processes. -- Art S. Kagel & Family kagel@erols.com
Thanh wrote: > We are moving from Online 5.0x to IDS 9.2x. > Our applications are all single-threaded. What can be gained, > and how much if a second CPU is added and we make no changes > in our apps ? > > Thansk, > Thanh > > Sent via Deja.com http://www.deja.com/ > Before you buy. A second CPU will allow improved PEAK performance in a multi-user situation. This will not be by a factor of 2 (100% improvement), but not far off from that - don't be surprised if its as much as a 70% improvement. That's because Informix will split the load of multiple sessions across the 2 cpu VPs. In a single active user situation under PDQ, benefits will derive as well. Whether you actually derive improved performance in a running system depends on whether CPU is your current bottleneck. If not, you may still derive latency benefits, reduced congestion spikes, etc Rudy
In article <38E25817.B10EBEC4@americasm01.nt.com>, Rudy Fernandes <rferdy@americasm01.nt.com> wrote: > Thanh wrote: > > > We are moving from Online 5.0x to IDS 9.2x. > > Our applications are all single-threaded. What can be gained, > > and how much if a second CPU is added and we make no changes > > in our apps ? > > > > Thansk, > > Thanh > > > > Sent via Deja.com http://www.deja.com/ > > Before you buy. > > A second CPU will allow improved PEAK performance in a multi-user "PEAK" is what I should have mentioned in my vague/general question. > situation. This will not be by a factor of 2 (100% improvement), but not > far off from that - don't be surprised if its as much as a 70% > improvement. That's because Informix will split the load of multiple > sessions across the 2 cpu VPs. > > In a single active user situation under PDQ, benefits will derive as > well. > > Whether you actually derive improved performance in a running system > depends on whether CPU is your current bottleneck. If not, you may > still derive latency benefits, reduced congestion spikes, etc I have read all the responses to date and I appreciate for your time responding to my question. I particularly find this answer to be more helpful, perhaps because I have just scanned chapter III of "Performance Guide for 9.2" about the VP concept where a certain Informix process is bound to a CPU. This, I think, is unique in IDS and not in Online. There are a lot of stuff out there to learn (Art's performance TA, and others). Hopefully, I will be able to post good questions in the future. Thanks everybody, Thanh PS. I've just started involving with database, in general, off and on, a couple of weeks ago, put aside Informix. Now, you know where I am coming from :-) Sent via Deja.com http://www.deja.com/ Before you buy.