UPGRADING SF12K Memory Solution
Currently my SF12K uniboard is configured with 4 CPU USIII with 8GB RAM.
Plan to upgrade another 4 GB RAM. All the 8 Banks with 32 DIMM is fully populated with 1GB (4x 256MB).
Solution Question:
Let say I upgrade only 2 banks with 4 GB (4X1GB). Will it be compatible and able to run with current memories which is 1GB.
What other requirement should i consider before upgrading?
Please advise urgent, else point me to the right direction
# 1
Hi Michael,
You probably get the following feedback from SunSolve, SE Guide even from Solution Center:
- DIMM's must be added in groups of four, no partially populated banks.
- All four DIMM's within a bank must be the same size.
- The minimum memory requirement is four DIMM's in Bank 0.
USIII Uniboard allowed 2CPU & 4CPU config and the statement on 0, 4, 8 DIMMs per CPU config is generally correct.
While the 3 basic rules tell us how a factory pre-configured board going to looks like, but never explain how to upgrade more DIMMs, although X-option memory modules can be purchased separately. We can't always upgrade our memory by 2x (even 4x) density from our original config and the question about DIMMs wastage will arise. In real life, we often need to solve the problem of shortage just 2-4GB memory per domain.
The whole "high-end" server memory upgrade seems so complicated and we SE often spending sleepless night browsing for answer(s)..... The "Sun Fire?High-End and Midrange Systems Memory Module (DIMM) Installation Guide" offers extra 2 tips
DIMM Installation Rules- Each DIMM bank must be fully populated with the same capacity DIMM.
- Install the larger capacity DIMMs into banks before installing the smaller capacity DIMMs into banks.
My understanding,
The installation guide didn't mentioned that "ALL" DIMM bank must be fully populated with the same capacity DIMM.
The 2nd statement further confirms that MIX capacity DIMMs can be configured, but with larger DIMMs first, then your old DIMMs at later bank(s).
You may need to check whether you 8GB RAM is made up of 16x512MB or 32x256MB. If your memory configuration is 16x512MB & you're going to upgrade 4GB RAM.
The following may work (but need Solution Centre to confirm)
- order compatible 4 GB (4 ?1GB SDRAM DIMMs)
- unplug 4x 512MB DIMM from CPU P0 Bank B0
- install 4x 1GB DIMM into CPU P0 Bank B0
- Install 4x 512MB DIMM into CPU P0 Bank B1
While doing these, i am observing "install larger capacity DIMMs before installing smaller capacity DIMMs", and i still keep the basic rules of "minimum memory requirement is four DIMM's in Bank 0" for CPU P1, P2 & P3.
