Re: [PERFORM] Quad processor options
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bjoern Metzdorf Sent: Tuesday, May 11, 2004 3:11 PM To: scott.marlowe Cc: [EMAIL PROTECTED]; Pgsql-Admin (E-mail) Subject: Re: [PERFORM] Quad processor options scott.marlowe wrote: Next drives I'll buy will certainly be 15k scsi drives. Better to buy more 10k drives than fewer 15k drives. Other than slightly faster select times, the 15ks aren't really any faster. Good to know. I'll remember that. In peak times we can get up to 700-800 connections at the same time. There are quite some updates involved, without having exact numbers I'll think that we have about 70% selects and 30% updates/inserts. Wow, a lot of writes then. Yes, it certainly could also be only 15-20% updates/inserts, but this is also not negligible. Sure, adaptec makes one, so does lsi megaraid. Dell resells both of these, the PERC3DI and the PERC3DC are adaptec, then lsi in that order, I believe. We run the lsi megaraid with 64 megs battery backed cache. The LSI sounds good. Intel also makes one, but I've heard nothing about it. It could well be the ICP Vortex one, ICP was bought by Intel some time ago.. I haven't directly tested anything but the adaptec and the lsi megaraid. Here at work we've had massive issues trying to get the adaptec cards configured and installed on, while the megaraid was a snap. Installed RH, installed the dkms rpm, installed the dkms enabled megaraid driver and rebooted. Literally, that's all it took. I didn't hear anything about dkms for debian, so I will be hand-patching as usual :) Regards, Bjoern - Personally I would stay away from anything intel over 2 processors. I have done some research and if memory serves it something like this. Intel's architecture makes each processor compete for bandwidth on the bus to the ram. Amd differs in that each proc has its own bus to the ram. Don't take this as god's honest fact but just keep it in mind when considering a Xeon solution, it may be worth your time to do some deeper research into this. There is some on this here http://www4.tomshardware.com/cpu/20030422/ Rob ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
Re: [PERFORM] Configuring PostgreSQL to minimize impact of checkpoints
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of scott.marlowe Sent: Tuesday, May 11, 2004 2:23 PM To: Paul Tuckfield Cc: [EMAIL PROTECTED]; Matthew Nuzum; [EMAIL PROTECTED]; Rob Fielding Subject: Re: [PERFORM] Configuring PostgreSQL to minimize impact of checkpoints On Tue, 11 May 2004, Paul Tuckfield wrote: If you are having a write storm or bursty writes that's burying performance, a scsi raid controler with writeback cache will greatly improve the situation, but I do believe they run around $1-2k. If it's write specific problem, the cache matters more than the striping, except to say that write specfic perf problems should avoid raid5 Actually, a single channel MegaRAID 320-1 (single channel ultra 320) is only $421 at http://www.siliconmechanics.com/c248/u320-scsi.php It works pretty well for me, having 6 months of a production server on one with zero hickups and very good performance. They have a dual channel intel card for only $503, but I'm not at all familiar with that card. The top of the line megaraid is the 320-4, which is only $1240, which ain't bad for a four channel RAID controller. Battery backed cache is an addon, but I think it's only about $80 or so. ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly - If you don't mind slumming on ebay :-) keep an eye out for PERC III cards, they are dell branded LSI cards. Perc = Power Edge Raid Controller. There are models on there dual channel u320 and dell usually sells them with battery backed cache. That's how I have acquired all my high end raid cards. Rob ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [PERFORM] Pg+Linux swap use
Not being one to hijack threads, but I haven't heard of this performance hit when using HT, I have what should all rights be a pretty fast server, dual 2.4 Xeons with HT 205gb raid 5 array, 1 gig of memory. And it is only 50% as fast as my old server which was a dual AMD MP 1400's with a 45gb raid 5 array and 1gb of ram. I have read everything I could find on Pg performance tweaked all the variables that were suggested and nothing. Which is why I subscribed to this list, just been lurking so far but this caught my eye. Rob -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Sullivan Sent: Friday, October 31, 2003 8:36 AM To: [EMAIL PROTECTED] Subject: Re: [PERFORM] Pg+Linux swap use On Fri, Oct 31, 2003 at 12:03:59PM -0200, alexandre :: aldeia digital wrote: Scott, Jeff and Shridhar: 1 GB RAM :) The stock kernels are not the same, HyperThreading enabled. 80 Some people have reported that things actually slow down with HT enabled. Have you tried turning it off? A -- Andrew Sullivan 204-4141 Yonge Street Afilias CanadaToronto, Ontario Canada [EMAIL PROTECTED] M2P 2A8 +1 416 646 3304 x110 ---(end of broadcast)--- TIP 8: explain analyze is your friend ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
