|
Last year, I made the move from 6- 8 GB drives to 6-17 GB, and performance suffered considerably. Al Al Barsa, Jr. Barsa Consulting Group, LLC 400>390 914-251-1234 914-251-9406 fax http://www.barsaconsulting.com http://www.taatool.com |---------+-----------------------------> | | Matthias Oertli | | | <matthias.oertli@m| | | di.com.au> | | | Sent by: | | | midrange-l-admin@m| | | idrange.com | | | | | | | | | 06/02/2002 09:05 | | | PM | | | Please respond to | | | midrange-l | | | | |---------+-----------------------------> >------------------------------------------------------------------------------------------------------------------------------| | | | To: midrange-l@midrange.com | | cc: | | Subject: Re: New 270. | >------------------------------------------------------------------------------------------------------------------------------| Hi, Thanks everybody for the discussion. It appears that the 8GB drives cost as much as the 17GB ones here as well. So 8GB's are out. >From a capacity point of view 4 17GB's are plenty. But after reading the various responses I'm now seriously considering getting two more for performance reasons. In the current box I have 6 4GB drives (6607), the loadsource being mirrored and the remaining 4 forming a raid set. The real constraint (as always) is budgetary. If I get the additional drives I'd definitely would want to get the 25G tape drive as well.... Best regards, Matthias > > Your point is well taken. I was being practical as opposed to > theoretical. If I was wrong in assuming that the model 400 currently > had six or less drives, then the statement about duplicating the number > of arms was not the best advice. I would generally add arms until I > reach some boundary, either the capacity of a disk enclosure or RAID > controller. In the case of a 270, this would be multiples of six. Once > the boundary is reached, then I would look more seriously at other > options, including adding main storage. > > If I could get equal benefit from adding a 17GB drive or 512MB of main > storage, I would add the drive. A 17 GB drive will cost slightly less > than the memory. Two drives would cost more than the memory. There are > other benefits to adding memory and with the recent price decreases; it > makes more and more sense to load up a system with excess memory. > > I agree that memory above the minimum will dramatically decrease the > number of physical reads required on any system and can reduce the > number of arms that would be required on a system with less memory. I'm > not sure that a system with a normal amount of batch throughput would > consider 1 GB of main storage excessive to the point that database pages > would consistently stay in memory. It seems as though each release of > all operating systems (not just OS/400) requires and uses more memory. > I've worked in technical sales support for the AS/400 and have worked > with a number of sales reps who have tried to lowball the hardware in > order to sell the software. Sometimes the customers decided to go along > with the rep despite my efforts. Because of this I have some > unfortunate experience with undersized machines. I have never seen a > system with 20-30 users doing order entry and other interactive tasks > survive with four drives, even with some excess memory. I have seen it > work with six. > > Mathias, how many drives do you currently have on your machine? > > The math on main storage works as follows. The system 270-2431 has > eight slots which will accept 256, 512, or 1,024 MB memory cards. A > single card may be installed; after the first they must be in matching > pairs. The 512 MB card is currently $1,792. The 1,024 MB card is > $3,584. The 8.5 and 17 GB drives currently list for $1,400. > -- -------------------------------------------------- Matthias Oertli matthias.oertli@mdi.com.au _______________________________________________ This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@midrange.com To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/cgi-bin/listinfo/midrange-l or email: MIDRANGE-L-request@midrange.com Before posting, please take a moment to review the archives at http://archive.midrange.com/midrange-l.
As an Amazon Associate we earn from qualifying purchases.
This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].
Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.
midrange.com
