Subject: RE: RE: Re: Michael: printing+reformatting hda13 from ext2 to hfs
From: Christopher Murtagh (christopher.murtagh@mcgill.ca)
Date: Thu Aug 23 2001 - 14:12:46 MDT
On Thu, 23 Aug 2001, Ruprecht, Chris wrote:
>I have worked 'on' the machine before and it's pretty fast, it used to
>support 500+ users simultaneously, but I have never actually seen the
>box itself. AFAIK, it has 4 GB of RAM and some RAID disks, but again, no
>details.
Wow, 4GB of RAM is better than anything you'll get on a G4! This will
likely help with your potential IO problem as well if you can get a lot of
your tables in RAM.
>But, at this point in time, as I'm not sure when I can get the Alpha
>machine, I would like to know what the speed differences between a Mac
>and an Intel box would be. I know the G4 is way fastern than the Intel
>chips, but a machine is not just the processor alone and the times where
>I fall for the marketing hype of this or that company went out with the
>70s ;).
I wouldn't say that a G4 is 'way faster' than an Intel box. It really
depends on what you are doing. If you were running Photoshop bakeoffs with
Steve Jobs, then go for the G4, not so sure about the real world though.
>I'm after real life database performance details. Unfortunately, my YDL
>box, a PM 9600, running YDL 1.2.1, is a little 'aged' and I would not
>quite trust any speed tests I do with it. The internal SCSI adaptor
>tells me that it syncs at 5 MB/sec to the 18 GB Ultra160 drive, I have
>in there. I know, I should try an adaptec 29160 but the only one I have
>(actually a 39160) is PC-only and the Mac doesn't recognize it, no
>matter how hard I try.
I'm currently using ATTO PCIExpressPro cards and they work really well
(Ultra-2 SCSI though). I do have one Ultra-3 card, but last time I tried
it, it wasn't supported by the kernel (2.2.17). I might try it again with
a 2.4 kernel.
> I could go and throw a lot of money at this old box, but it's not worth
>it, so I'm not even going to try. But I'm also not quite willing to
>invest into one of the new G4 (yet), since I don't know what it's
>performance will be.
We are currently running PostgreSQL on a Dual G4/500 here with 512MB of
RAM. Our course calendar is now online for the first time, and we have
hundreds of students looking up course info. Performance is pretty good
(better than we had expected) and we aren't even using a kernel that uses
the 2nd CPU. I'm hoping to upgrade the kernel so that I can use the second
CPU and more RAM in the near future.
One thing is certain though... keep your database and web server on
separate hardware. You want as much of your DB cached in RAM as possible
(ideally all of it), and you don't want your web server bumping it out of
the cache for web pages. Also, this lets you update hardware on one while
the other is still running. Luckily, the cost of the G4s (compared to DEC
machines that support 4GB of RAM) is pretty cheap, so bang for buck is
pretty good.
Cheers,
Chris
--Christopher Murtagh Webmaster / Sysadmin Web Communications Group McGill University Montreal, Quebec Canada
This archive was generated by hypermail 2a24 : Thu Aug 23 2001 - 13:21:10 MDT