Addindum: Summary: How much time can I save if I....

From: Ron Bramblett <bramblet_at_fuller.com>
Date: Thu, 16 Aug 2001 07:35:34 -0500

Hello,
This is just an update.

I was asking about computing time saved about a week or more ago. I
have an AS2000. It had 128 MB memory, 1 233 CPU, 1 TLZ09 Tape drive.
4.0g for the operating system.

According to the summary below, it would not help much if I did the
upgrade I was proposing. (Adding 128 MB memory and 1 233 CPU, replacing
the TLZ09 with a TZ88)
I was almost already commited to doing something. I was under pressure
from the boss to do something and even though the numbers said nothing
would happen. I went ahead and did the upgrade this past weekend.

On Sunday I did not think it changed much. On Monday I was still under
the same impression. Not good at all. The operators don't do processing
until Monday night. The users could not really tell much of a difference
during the day. On Tuesday morning when I came in the operator told me
that the system came up 3 hours early and was ready to use. The numbers
I looked at before had changed and showed the memory was being used
better and so was the CPU's. Today after 2 more days of faster
processing at night. I think that it is working like it should.

I have an issue with a tape drive but different topic. I want to thank
everyone who helped me with this project. Now the boss is happy. Thanks
so Much.

Well here is the summary for what it is worth.
> Original question:
>
> I am in the process of upgrading my Alpha Server 2000, 128MB memory,
1
> 233 CPU, 4 4.3 GB raid5 disks, 4.0g to a faster system.
> I am proposing 128MB memory, total of 2 233 CPU's 4 9.0 GB raid5 hard

> disks.
> I need to know how I can calculate how much time will be saved if I
do
> this upgrade. I know I can cost justify it by the $ wasted in waiting

> on
> nightly processing (the plant needs the system up at a specific time
> and
> if it isn't that is $$)
>
> I know the amount of memory I am swapping out, Where do I start?? I
> need
> to know yesterday. :)
>
> Thanks to : Alan _at_compaq, Dr. Thomas Blinn, Jim Belonis, Tony
McElhill,
> Joe Fletcher, and Pat O'Brien
>
> Quick answer. It is impossible to tell. Nobody on earth can tell what
> will happen.
>
> After research and studying the numbers answer: I am wasting my time
and
> money by performing this upgrade. It won't help my system at all.
>
> to see if an additional cpu will help (I am using the collect utility)

> I looked at the User + Sys times. My average for a month is
36%
> I also looked at the Idle + Wait times. My average is 63%
> Also look at runq time. My average is 0.99
>
> to see about the memory look at the memory portion of collect.
> Look at device activity of the swap space device if seperate.
mine is
> seperate avg of 1.26%
> Also look at the paged out (PO) section. My avg is 0.13 MB /
Sec.
>
> Hard drives
> Look at the i/o rates on the specific hard drives. If you are
using a
> faster one then it might help. Can't determine it.
> Tape drives
> Look at the I/O rates on tapes. (have to catch them when they
are
> actually busy). If a tape drive is faster more reliable it will help
but
> how much to be determined by adding the tape drive and then watching
the
> before and after results.
>
> >From Jim Belonis
>
> First you need to know what bottleneck there is and whether the
> specified upgrades will address it.
>
> If your bottleneck is disk I/O, then your upgrade probably won't
affect
> it much.
> If your bottleneck is CPU, the 2nd CPU might help.
> If your bottleneck is swapping, the upgrade probably won't help,
> you would need more RAM instead.
>
> If your 'nightly processing' takes all available CPU time
> for protracted periods, and it can be helped by two CPU's
> (i.e. multiple processes are running at once, or a single
> process has been written to take advantage of multiple CPU's)
> then hot damn ! you're in business.
>
> Calculating how much time will be saved is MUCH more difficult.
> It probably can't be done without sticking in a 2nd CPU and
> experimenting.
> Talk to Compaq (or is it Intel now ?) and see if they will lend you a
> CPU
> to test, or can find a dual-processor system you can test on.
> Or buy a 2nd CPU with the guarantee that they will take it back
> if it doesn't help.
>
> Jim Belonis


--
Ron Bramblett
Systems Admin
Fuller Brush Company
Received on Thu Aug 16 2001 - 12:35:48 NZST

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