RAM upgrade

[Former Member]

Hi Gurus,

We are having ECC 5.0 with 8 GB RAM as the performance of SAP is slow, We have upgrade RAM from 8 GB to 24 GB ..

Please let me know what are the parameters that we have to change after RAM upgrade for effective usage of RAM. and to increase the performance of SAp R/3 System...

Thanks in advance

VJ

[Former Member]

Before changing parameter check whether your Hardware and Operating system will support 24GB RAM. If your H/W and OS is supporting 24gb then you can change the memory parameters as per SAP recommendation or as jun said

https://websmp230.sap-ag.de/sap(bD1lbiZjPTAwMQ==)/bc/bsp/spn/sapnotes/index2.htm?numm=97497

Edited by: ravi m on Apr 16, 2009 10:41 AM

[Former Member]

If your system is windows based then check for settings /3gb, /PAE in the boot.ini

[Former Member]

Manoj,

Tell me how to set the paging memory in boot.ini file...

VJ

[Former Member]

Vijay,

Tell me how to set the paging memory in boot.ini file...

you do not set paging file size in boot.ini. To set paging file right click my computer->properties->advanced->performance -> settings->adavance-> Virtual memory.

Read following articles for /3GB and /PAE modes.

[http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx]

[http://www.microsoft.com/whdc/system/platform/server/PAE/pae_os.mspx]

[https://websmp130.sap-ag.de/sap(bD1lbiZjPTAwMQ==)/bc/bsp/spn/sapnotes/index2.htm?numm=1102149]

Manoj

[Former Member]

Hello

we are using the 8gb ram on our PRD server, we have concurrent 230 users are online, we did not get any complain about degrade perforamnce.

The performance problem arise one of the factor of the hardware but there could be many other factors which degraded performance, like expensive sql statement and system not configured properly, whcih did not optimze yet or tune yet as required! You can monitor the workload on st03n once you get complained !

Also, you can schedule to EarlyWatch check whcih will highlight the issues and give you recommendation which need to be set on your PRD server for the better perforamcne.

Regards

Anwer Waseem

[Former Member]

It is kind of hard to give a good advice, without knowing why your system is slow. However i can give you some general guidelines. But you will have to do some research yourself if you really want to improve the situation.

If you have performance issues on the database side, then you need to increase the database buffer. For oracle this would be the parameter db_cache_size.

On the SAP side check ST02 for the abap buffers, especially for program buffer and table buffers.And you might also consider increasing em/initial_size_MB and abap/heap_area_total.

Please do under all circumstances verify that you do not exceed the physical memory, because os paging is one of the top reasons for memory related performance problems.

Best regards, Michael

[JPReyes]

You need to look into all memory parameters like,

em/initial_size_M

em/max_size_MB

PHYS_MEMSIZE (depending on OS)

Usually then you need to review the size of your Page file which usually should be 3 to 4 times the size of your RAM

after that you can review the size of parameters

abap/buffersize

ztta/roll_first

ztta/roll_area

ztta/roll_extension

abap/heap_area_total

abap/heap_area_dia

abap/heap_area_nondia

Thats plenty to start with.

Regards

Juan