Saturday 9 June 2007

System Builder Tip: Server processor/CPU caveats when Intel server system building.

Yesterday, I mentioned that we had a bit of a struggle getting some Xeon 5130s working on what turned out to be a pre-production S5000PSL server board back when the Xeon 5130s were newly released. Blog post here: System Builder Tip: Intel S3000AH Server Board Series BIOS Updates Available.

When we sell server product, one of the selling "features" should be future upgrades to the server to meet further growth of the company. Yet, in today's server world, this is not the case.

How is that?

Let's say that in the case of the above S5000PSL we only installed a single Xeon processor. Say, the Intel Xeon 5130 SL9RX. We note that the Core Stepping is B2.

So, a year and a half down the road we need to add a second processor. The Xeon 5130 processor may still be in production, but we can only install a CPU with the same stepping code as the existing one, that is B2. More than likely, the stepping code on the then in production Xeon 5130 would be B3 or B4 or even higher! So, we would need to comb the Internet looking for the right one. Or, we would have to buy two (2) processors from our supplier anyway.

And therein lies a very serious caveat: The earlier revision of the server board may not support the newer stepping code CPUs or more Cores even with a BIOS update!

Here is a practical example based on an experience we just had with a server upgrade:

Here is a picture of the PBA code on the existing S3000AH that we attempted to upgrade yesterday to a Xeon X3210 Quad Core processor:

Note that the last three digits in the PBA number are -204. This is the board's revision level.

Now, here is what Intel's Web site states for X3210 compatibility:

In the last column we have some Notes numbers.

Here they are:

Our Intel Xeon X3210 CPU in note 7 requires a server board revision of -206 or above.

Thus, our installed S3000AH board at revision -204 does not qualify. Even with a BIOS update, the -204 board will not support the X3210 or X3220 Xeon Quad Core processors as indicated in the above Notes. In every other way, they are essentially identical!

We were fortunate that we had an S3000AH with a newer revision level here in the shop:

Our in-shop server board was revision -207.

When doing a straight across upgrade like this, that is, one S3000AH -204 for one S3000AH -207 one must make sure to flash the -204 to the newest BIOS version FIRST. Then boot the system up into the BIOS to verify the settings, then boot into the OS, with the -204 board still in the system, to make sure the OS doesn't take a fit over the BIOS update. Everything should work out okay up to this point.

To rephrase: Before making any physical changes to the server:
  1. Update the BIOS.
  2. Boot into the BIOS and verify settings especially the RAID controller LSI vs. Intel Matrix, save, and reboot if any changes were made by the BIOS update.
  3. Boot into the OS to verify its acceptance of the new BIOS.
  4. Shutdown the system.
Begin the hardware swap after that.

As soon as the server board swap is complete, boot directly to your BIOS update thumb drive and update the -207 to the S3000AH BIOS version as above (revision 42 as of this post).

Once the BIOS update is complete verify your BIOS settings as above!

There are two (2) RAID controllers built into this server board: The LSI based one and the Intel Matrix Technology one. Your OS may choke and not boot if the wrong one is configured.

If you had RAID array(s) configured on the previous server board, they will be picked up by the newer server board RAID controller with no issues. At least, that is what happened here with us as we verified the RAID controller type beforehand. Take note, both RAID controller versions picked up the RAID arrays, but the OS may still choke on the wrong controller!

When explaining to the client what may happen, we qualify our quote with options as far as what may happen if we run into this situation. Best case scenario and worst case scenario. We get approval for both as we provide costs for both.

Due to the complexity of inter-CPU stepping compatibility along with CPU type to server board revision level compatibility we always build our dual processor servers with two processors installed.

If our client is planning on having a large influx of employees over the life of the server, then we will install faster CPUs and more RAM too. We will build a server that will meet our client's needs for a minimum of two years as best as we can based on their budget.

If we are dealing with a smaller client with a rather static employee pool that only needs a one processor based server, we will sell a uniprocessor server system.

Given the above S3000AH server board revision compatibility situation, as well as the S5000PSL revision compatibility situation we were in before, we are careful about adopting new server technology.

In the case of early adopting, there are no guarantees that the server board revision purchased will be compatible with future CPUs. Thus, virtually no future upgrade scenarios will exist.

Some S3000AH specific Intel links:

Philip Elder
Microsoft Small Business Specialists

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