[K12OSN] Client RAM question

Jim Kronebusch jim at winonacotter.org
Mon Mar 29 15:04:57 UTC 2004


I have been watching this thread and will just throw in some of my
observations from my testing (I don't have a actual lab in use yet so
take this with a grain of salt).  
1. Largest speed gain is in network speeds 10MB crap, 100MB great, 1GB
awesome
2. Next best gain is in video for apps like tux math and type, I haven't
had time to find the best cards, but video cards make a huge difference.
I can have 2 machines with 128MB RAM and with 100MB connections and tux
math is perfect on one and unusable on the other, only difference is
Video Card.
3. RAM seems to be optimal at 128MB.  They turn on with 32MB, they work
with 64MB, they make me happy with 128MB.
4. Processor is not too important, I have used a 180MHZ machine side by
side with a 800MHZ machine and as long as other variables like RAM,
Video, Network are same, so is everything else.  With that said don't
take this to an extreme and throw in your 66MHZ boat anchors, I am sure
anything slower than 180MHZ will start to lag, and keep in mind that
there is reliability problems with stuff that was around in 1988 :-)

As far as server side goes I have seen plenty of postings here backing
up 100-128MB per client on the server.  I have also seen plenty of
feedback recommending SCSI, I myself prefer a SCSI Raid5 for any server
that sees a lot of data access.  I have also seen that Dual processors
are a must with over 15 clients but have not seen any feedback about the
effects/advantages of quad processor machines.  In the dual 2.XGHZ range
with SCSI Raid 5 and 4GB of RAM I have not seen anything backing up the
ability to serve any more that 40 concurrent users.  From that point on
it sounds like clustering or load balancing is the ticket.

But keep in mind, I have no idea what I am talking about :-)

-----Original Message-----
From: k12osn-bounces at redhat.com [mailto:k12osn-bounces at redhat.com] On
Behalf Of Rita Gibson
Sent: Saturday, March 27, 2004 8:04 AM
To: A technical support and discussion community for users of the K12OS
Linux distribution.
Subject: Re: [K12OSN] Client RAM question


Terrell Prude', Jr. wrote:

> Julius Szelagiewicz wrote:
>
>> On Fri, 26 Mar 2004, mella wrote:
>>  
>>
>>>> From: "Terrell Prude', Jr." <microman at cmosnetworks.com> No, it 
>>>> shouldn't.  None of the apps are actually running on the client at 
>>>> all; they're all running on the server and merely are displayed on 
>>>> the client.  The only "large" app running on the client is the X11 
>>>> server itself, and that fits nicely into 32MB.  Most of my clients 
>>>> have
>>>>     
>>>
>>> <32MB DRAM, and they run just as fast as if they have 48MB or 64MB.
>>>   
>>>
>>>> Matter of fact, I've actually pulled DRAM out of a client so that
>>>> it'll
>>>> boot faster (less DRAM to go through during POST).
>>>>     
>>>
>>> Wrong answer!
>>> I use k12LTSP4.0.1 , 30 clients with Dual Xeon + 4G RAM.
>>> My clients use many memory-wasting programs like Mozilla, OOO and
>>> Evolution.
>>> I noticed strange restarts on clients with 32MB RAM. Even with 64MB.

>>> But clients with 128MB RAM never restarted.
>>> So, I added NFS swap up to 96MB per client and now all is ok. No 
>>> more restarts.
>>> So, amount of client RAM IS important!
>>>
>>>   
>>
>> Mella is right - the amount of client memory matters, because the X
>> server
>> got "smart" and uses more memory to reduce network traffic. 128MB 
>> seems to
>> be the magic number. julius
>>
>>  
>>
>
> Hey, I can only relate my experience, and that says, "no difference."
>
> Julius, I hadn't heard about the X11 server getting "smart."  I'd of
> course like to know more.  Given that the apps are running on the 
> server, not the client itself, how does this "smart" bit work?  We're 
> just displaying stuff, aren't we, or are we somehow migrating apps 
> over to the client under the hood, a'la OpenMosix?
>
> Please enlighten me; you've got me curious!
>
> --TP

I am very interested in this discussion as I am trying to figure out how

to get a little better performance in our lab. I have been trying to 
decide whether to try to migrate all the boxes I have that would hand 
128MB into the lab -- performance is always an issue when you have a lab

full of excited students trying to get their work done. If the client 
has more memory, then does the server do less swapping for that client 
(thus less processor time and bandwidth?).

Thanks for this discussion.

Rita Gibson
RMSEL


_______________________________________________
K12OSN mailing list
K12OSN at redhat.com https://www.redhat.com/mailman/listinfo/k12osn
For more info see <http://www.k12os.org>

---
Incoming mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.643 / Virus Database: 411 - Release Date: 3/25/2004
 

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.643 / Virus Database: 411 - Release Date: 3/25/2004
 





More information about the K12OSN mailing list