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HP Recommended
Microsoft Windows 10 (64-bit)

I'm trying to optimize the performance of a small fleet of xw8400s and xw8600s at our community radio station.


The HP xw8600 Workstation Service and Technical Reference Guide says when installing more than 2 DIMMs, to install them in matched pairs, beginning with slots 1 and 3, then 5 and 7 followed by 2 and 4 and  finally 6 and 8 in ascending order of size, beginning with slots 1 and 3.


When I press F10 during startup and then view the SYSTEM INFORMATION display, I see the following information on this xw8600:

Channel  0             #1:4096M  #2:4096M

Channel  1             #3:4096M  #4:4096M

Channel  2            #5:4096M  #6:4096M

Channel  3            #7:4096M  #8:4096M



Are those numbers above (#1 through #8) really the slot numbers containing the DIMMs? If that's the case, and if we install different sized DIMMs pairs per the xw8600 Workstation Service and Technical Reference Guide, wouldn't we see different sized DIMMs in each channel?


For example, if we install four 1GB DIMMs in slots 1, 3, 5 & 7 and add   four 2GB DIMMs in slots 2, 4, 6, and 8 which is said to be a correct way to obtain 12GB of RAM, would we see different sized DIMMs in each of the channels?


Do I really need to know this? Well, if I want to ensure that DIMMs are installed correctly, I would rather rely on the SYSTEM INFORMATION display in the F10 setup menus than having to open the workstation and remove all of the DIMMs to make sure they're installed according to the xw8600 Workstation Service and Technical Reference Guide guidelines.


HP Recommended

again,............channel slot/bank load order is printed on the side cover of the system of both the 8400/8600 systems


slots 1/3 is a bank consisting of two dims


slots 5/7 is a bank consisting of two dimms


and if you do not have both cpu's installed then the available banks that can be used (memory inserted) is half of what a dual cpu system uses (IE dual system uses all banks slots if desired)

HP Recommended

Before flying off the handle again and insulting my ability to read the  instructions in the manuals or on the inside of the cover, please reread the original post. If you are not still angry, I would appreciate a kind response.


The question was not about the proper order in which to install DIMMs. It was about the way the actually-installed DIMMs are displayed in the F10 System Information window.


If the numbered positions correspond to the physical slot locations (they do), then the System Information display shows that the matched-pair DIMMs installed in slots 1 and 3 are assigned to Channels 0 and 2 respectively, yet at the same time, as you say, they are in Bank 1.


Can you explain the difference between Channel assignment and Bank membership, assuming there is one?


Alternatively, perhaps you could be helpful and explain why the System Information display identifying the actually-installed DIMM locations is not organized by Bank rather than Channel.


Dennis, aka "d2b"



HP Recommended

I am not angry,.......what i'm trying to do is answer your questions.....however it appears that you have a very basic understanding of computers and the terms used and as such are having trouble with the answers given 


if you keep at it you will get better at understanding


i'll try yet again to give you a answer


the memory banks/order on the board are laid out due to electrical reasons


the memory load order is due to HP deciding that smaller to larger is the best/proper load order for the memory controller that is used on this board


the boot up onscreen display showing the installed memory banks is listed as such because that's what the people who wrote the bios decided was the most suitable layout


explain the difference between Channel assignment and Bank membership?


I might,...... but i don't think you will understand the answers as i'm not sure you really know what your actually asking about you might want to read this link and see if they pertain to what you want to know




as for Bank membership,...i have no idea what you mean by this

HP Recommended

Your yourself used the term Bank to describe the pairing of DIMMs according to the recommended order in which to match and install them.  Having said that, it seems logical to identify the paired DIMMs in slots 1 and 3 to be members of the same bank.


Of course I do not understand all of the complexities involved in the various means to optimize a workstation's use of RAM. I should not have to know this, even though I have an MS degree in Electrical and Electronics Engineering. My quest was to make certain that I can review and thereafter ensure that our modest fleet of HP workstations are optimally configured w.r.t. DIMM installation order for best performance.


The presumably easiest way to find out how a workstation's DIMMs are installed, and thereby determine if the proper installation order was followed back in the day, I look to the F10 System Information screen for DIMM location information. The System Information display shows that slots 1 and 2 have some kind of paired relationship (Channel 0) that to the average user (me) flies in the face of the instructions to install  DIMM pairs, first in odd-number slots and then in even-numbered slots, in ascending order of storage capacity.


At the time I made the original request for clarification on this issue, I wanted assurance that the numbering of the DIMMs in that System Information display , for example, #3, corresponded to Slot 3 on the motherboard. I have since confirmed by experimentation that the numbering in the display has a one-to-one correspondence to the slot numbers. That's really what I needed to know.


That said, listing the DIMM locations by Channel number in the System Information screen, whatever that means to someone else, is confusing to a user like me that wants assurance the the DIMMs are properly paired and in the right slots. It's not obvious why slots 1 & 2 also seem have a different paired relationship belonging to Channel 0.


I would not have had to ask for clarification had the System Information screen for installed DIMMs been organized like this:


Bank 1:         #1:...                     #3:...

Bank 2:         #5:...                     #7:...

Bank 3:         #2:...                     #4:...

Bank 4:         #6:...                     #8:...


Of course this format would also be confusing to those that are told when installing just one DIMM to put it in Slot 1 and when installing only 2 DIMMs to put them in Slots 1 and 5.



HP Recommended

Are you saying that only slots 1 and 3 (as a matched pair) and 5 and 7 (also as a matched pair) can be used in one-cpu versions?


As it turns out, we have four identical 2GB DIMMs in these slots and still receive a single "beep" when booting, along with a "failing rank" message (which is Greek to me)., followed by information that the system recognizes only 6GB some times and just 4GB at other times. All of these DIMMs test OK in other 2-cpu systems.


Could this be a motherboard or socket problem rather than a problem with the DIMMs or their installation pattern?

HP Recommended

final time,....[edit]


  please read the HP service manuals for your workstations

HP Recommended

"We appreciate your feedback. It's what keeps our community such a helpful, vibrant place for our members."


I have RTFM several times. Special considerations for 1-cpu systems are not covered. You could have simply answered the question I posed, but ....

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