If you mean you are upgrading your 4GB DIMM's to 8GB DIMM's, then yes, you must update your BIOS, as Todd has said.  If, however, you are simply  upgrading your total RAM from 4GB to 8GB, a BIOS update is not required, but definitely recommended.  You BIOS is very old and many memory issues have been addressed in newer BIOS versions.

Also, If you are upgrading to 8GB DIMM's, they will ONLY work (with updated BIOS) in 2950 II and 2950 III servers - not the original 2950, which has a maximum of 32GB of RAM - even at the latest BIOS.

Thank you guys for your answer,

We have several 2950, each with 4Gb RAM. We planning to change the memory with 8Gb (2pcs) using Kingston KTD-WS667/8G for some server and other add  memory using base 2950 memory 4 Gb  for making total 8Gb RAM.

how do we check offsite 2950 version  ? I'm not sure it is version I, II or III .

And what we need to assure when we updating the bios ? Is there possibility will make server failed to start?

Thanks and Regards

Budiono

If you're curious as to which model you have, and you are not onsite, you can check one of two ways:

1. Check the order details for the server ... Original System Configuration tab (if you have questions about what you are seeing, post that portion here, minus Service Tag):
http://support.dell.com/support/topics/global.aspx/support/my_systems_info/details?c=us&cs=19&l=en&s=dhs

2. If OpenManage Server Administrator is installed (if not, you can install it), you can check under System, Main System Chassis, Information sub-tab, System Revision.  (Although, you will need to update your BIOS and BMC before this information will be available here.)

Also, since all three system revisions support 4GB DIMM's, it won't much matter which one you have.

When updating the BIOS, you usually are ok jumping from an old version straight to the latest, but if you wish to exercise a bit of caution, you will want to update in steps:

Make sure BIOS is at 1.3.7 and BMC at 1.33, then go to BIOS 2.3.1 and BMC 2.37, then to the latest BIOS (2.7.0).  BIOS updates require a reboot, BMC updates do not, but the fans will speed up and monitor flicker for up to 10 minutes during the update.

BIOS 1.3.7:

BMC 1.33:

BIOS 2.3.1:

BMC 2.37:

BIOS 2.7.0: