problem that shows 32GB RAM but Usable 24GB RAM

[lse123]

i replaced RAM DDR2 ECC DIMMs 4 x 1GB with 8 x 4GB:

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/i-want-replace-RAM...

I have a problem that shows 32GB but Usable 24GB

https://answers.microsoft.com/en-us/windows/forum/windows_10-performance/i-inserted-new-ram-but-rath...

I inserted new RAM [32GB DDR2 used chips ECC] but rather 32GB shows usable 24GB is RAM malfunction????? on booting appears error slot 2...well?  CAN WORK LIKE THIS OR NEEDED to FIND THE ERROR???

SOMETIMES SHOWS 

Memory Warning Condition Detected Slot 2 sometimes Slot 4

where is SLOT 1 [ONE] ??? Does numbering start as shown from RED arrows?? start 1 or 0 ???

more shots:

[DGroves]

when filling all slots on a FBDimm based system, make sure the ram cooling fan is installed and working

i have seen issues with some non hp certified modules have issues making good contact in the socket, try cleaning each ram modules pins with a pencil eraser and wipe clean with 98% isopropyl alcohol

the HP xw workstation will mark which ram bank is having a problem, so try swapping that module with another one and if the error also moves, replace the module

yes, the system will work with a bad module, but this will cause performance issues

[lse123]

Thank you for replying

SOMETIMES SHOWS 

Memory Warning Condition Detected Slot 2

sometimes

Memory Warning Condition Detected Slot 4

According to the first photo appended in this post from camera shot - showing inner PC RAM MODULES with me make some RED ARROWS with graphic software on the picture

for this PC the RED ARROWS show the MODULE 1 or 8 ??? 

In other words, the module start as shows the RED ARROW from 1 or from 8...? The count is zero-based 0 or one 1 based??

[DGroves · Accepted solution]

please LOOK AT THE INSIDE OF THE SIDE PANEL there is a label showing the dimm load/slot order/numbering

this is also found in the xw6600 "service manual" available for downloading on the HP site (GET IT)

[lse123]

HP xw6600 Workstation - Removing and Replacing the Memory

https://support.hp.com/si-en/document/c01319077 

HP xw6600 Workstation - Removing and Replacing the Memory

you have any idea how:

3. Remove the memory fan and system fan.  // How I remove system fan ???

I make removed memory fan but system fan --- I do not know how to remove???

[DGroves]

read the xw6600 service manual, read the xw6600 service manual

it's called the "SERVICE" "MANUAL for a reason

removing/replacing  the factory cooling fans is not a good idea, they are tuned to the case/system, and 3rd party fans will usually result in suboptimal cooling and/or increased noise

https://support.hp.com/rs-en/product/hp-xw6600-workstation/3432821/manuals

[SDH]

For some reason that manual is hard to find... it is HERE .

The number for each slot is printed on the circuit board by the slot.... they are hard to see so you will need good glasses and a flash light.  The numbers you showed in your first post.... the slots begins with 1 at the bottom and go up to eight 

Look at page 53 in the manual.... it shows them there and as DGroves said it also should be on the inside of your side case cover. 

In case you're interested:  I posted a few days ago on the exact 8GB sticks we've use in the xw6600 and the xw8600 workstations for years.  You can find those on the US eBay site for about 6.00 USD each, and I gave the exact Elpida model to search for on eBay ( EBE82FF4A1RQ-6E-E ).  These did not exist or were not tested by HP when the xw6600 manuals were created but are server memory sticks and work fine.  I use 4 of them instead of eight 4GB sticks to allow best airflow between them.  I have not tried running eight of the 8GB sticks...32 GB total is fine and to run 64GB may not work and potentially would draw too much power.  Place 4 of them in the dark plastic memory slots, and leave the white plastic memory slots open so the memory fan can keep them cool.  HP has said to fill the dark plastic slots first and that is why I came up with this method that works.  It will not work in a xw6400/xw8400 because they have an older memory controller chipset.  I tested that years ago....

Sometimes just cleaning the contacts of each stick with high percent isopropyl alcohol will get the whole set running fine.... you can get 90% from a pharmacy store.

[SDH]

I just had a thought.....

I'm hoping you actually do have the official HP memory fan that is supposed to be installed over your memory bank.  If someone threw that out in the past you really should get one.  There never was a configuration where the workstations were sold without that. 

[SDH]

And, another thought:

I noticed in your first picture that you're only running one processor, the E5405.  That is the lowest end quad core HP ever certified for your workstation, and the best one is the E5450.  Some of these processors had more than one version (a later "stepping" such as the E0 version rather than the original C0 version is always preferred).  To look up best price used on eBay search for SLBBP for the E5405 and search for SLBBM for the E5450.  I always upgraded to two of the SLBBM processors in all of our xw6600 builds.  Current lowest price is $11.65 USD each, free shipping.

Why add another processor?  The architecture of these is that the two processors work together best, and running with just one cripples your workstation.  We here have been using the Passmark scores as a general judge of performance.  A single E5405 as you are currently running gets you 1595, but running two of those gets you 5127.  For the E5450 a single processor gets you 2471 and running two gets you 5304.

You'd also need another heatsink/fan, and you can find those used off eBay also.  Just search for xw6600 heatsink or xw8600 heatsink.  You already have one of these so you can see what they look like.

[lse123]

Thank you for the service manual link

Since my PC can have a second processor XEON and having currently only one... XEON... If I decide to add a second [used from eBay]  processor, this second add processor should be exactly the model of the first processor???? Or can it be of the model ...?

The processor currently is as seen in Windows and BIOS shots,

Are you suggest to buy two XEONs since they are cheap from eBay and replace the current one... with a more powerful model... XEON?