8GB Memory Modules for xw8400 / xw8600?

[GKrembsler]

Hello,

i own a xw8400 and want to use 4x8GB memory modules.

I bought 64GB (8x8GB) DDR2 FB Fully Buffered PC2-5300F 667 Memory and they are accepted by the system.

But - after some time the computer goes down / is switched off. There's no bluescreen or other hint helping to find the cause. The machine is switching of like pulling the power cord.

At first i thought it might be a cooling problem. So i checked the temperature and it seems to be in regular limits (about 28-30°C air temperature).

I found info in the web, that 32 GB on that machine (2 CPU) should only be possible with a riser card (8x4GB). On the other hand it might only be a result of the fact that 8GB modules were not available at this time.

I have two questions:

* Is it possible to use 8GB modules on a xw8400 system with 2 CPU?

* i am currently testing the modules with memcheck but is there any way to get diagnostic information why the system is shutting down?

Thx G.

[SDH · Accepted solution]

This might relate.  I have not confirmed this but I believe the memory controller on the xw8400 is the same as on the xw6400.  

I noted for a prior project that HP officially supported specific 8GB sticks in the xw8600, and that the xw6600 and xw8600 memory controllers were the same.  That gave me the idea that perhaps, though not documented, those same sticks for the xw8600 could work properly in the xw6600.

I got some of those HP 8GB sticks and confirmed that they would run in my xw6600 builds just fine.  But, they would not run in my xw6400 builds.... same sticks, same perfectly functioning workstations if they had HP 4GB sticks in place.

I believe you are running into a memory controller issue on that older generation xw8400 workstation..... the earlier (6400/8400) and later (6600/8600) generation workstation familes I note above have different memory controller chipsets.

[GKrembsler]

Thanks for this explanation.

It makes sense, allthough i am running the 8 GB modules in the xw8400 for more than 24 hours with memtest and no error, maybe something with the memory controller is causing this problem.

I have a second xw8400 and maybe it has a newer controller chipset. Than i will test, if that makes a difference.

Also i try to get a used xw8600 as it supports 64 GB and maybe it works with this computer.

Thx for this solution...

G.

[tomk3212]

I have TWO xw8600s (yes, i DO like these beasts!!); one I use as an ESXi box and the other as a Windows Server 2012R2 server.  Both of them use 8GB memory sticks with absolutely no issues whatsoever.

The ESXi box has the memory riser cards and a mix of 8 & 4GB memory sticks for a total of 96GB which is PLENTY for the VMs that I run.  At some point I may "bite the bullet" and purchase an additional 8 sticks of 8GB RAM but that's for another posting.  BEFORE I purchased the memory riser cards I had the first 8 sticks of 8GM RAM installed directly onto the Mboard.  These ran for several weeks w/o any problem.

The other xw8600 box was originally one of my Windows 10 workstations that I re-purposed as a Server.  For that box I purchased eight 8GB sticks of RAM that are installed directly onto the Mboard.  It's been running about a week now with no issues so far.

My 2 cents.

[GKrembsler]

i guess the problem is with the 8400 machine not accepting 8GB. The 8600 seems to not have a problem with these modules.

[SDH]

The two generations have different memory controllers.

The xw8600 and the xw6600 have the same memory controllers.

Officially the xw8600 supports use of 8GB sticks, and the xw6600 does also (but not officially), assuming they are the correct type of 8GB sticks.

No go on the xw6400 or xw8400 with the exact same sticks that worked in the xw6600 and the xw8600 during my testing of this.