Highlighted
ckline
Copper

OptiPlex 980 16GB RAM Issue

Community - 

I have having a very strange issue regarding some OptiPlex 980 machines -- both SFF and MT variants.

With the following specifications, the units work perfectly fine:

Dell OptiPlex 980
Intel Core i5-650 @ 3.2GHz Dual Core
DP/N C522T or DP/N D441T Motherboard, BIOS Revision A15
8GB PC3-10600U Branded RAM or 8GB PC3-12800U Branded RAM
160GB Intel SSD SSDSA2M160G2GC
Windows 7 Pro

When the systems are updated to the maximum supported RAM (16GB), they fail to boot. The machines POST, go through all the motions until "Loading Windows" comes up, then restarts. Power cycles indefinitely. This activity will persist with any 4GB sticks installed, regardless of speed.

I have attempted reinstallation of several OSs, but after installation files are loaded, the machines restart. I have attempted Ubuntu, Windows 7, and Windows XP installation.

The machines will return to full functionality once any configuration of 2GB DIMMs or lower are installed.

I have tried the following solutions:

1. Changing memory: 32+ different 4GB DIMMs that are fully functional in other machines, including OptiPlex 980 models. Tried PC3-10600U and PC3-12800U of several different brands. Issue persists with any 4GB DIMM. 

2. Resetting the unit via CMOS battery removal: Issue persists

3. Disabling onboard graphics: Three completely different graphics cards where installed via PCI and issue persists

4. PSU upgrade: Issues persist with a 1000W power supply installed on a MT unit

5. Installing a standard hard drive: Issues persist with 3 separate 7.2k RPM hard drives.

6. Unplugging all unnecessary hardware: Motherboard, processor, hard drive, 1x4GB, PSU = issue persists

7. Changing processor: Issue persists

8. Changing BIOS revision: Issue persists with revisions A04, A09, A13, and A15

Again, units work fine with 2GB sticks, but do not with 4GB DIMMs, even though the maximum supported RAM is 16GB. Please help.

0 Kudos
14 Replies
speedstep
Diamond

RE: OptiPlex 980 16GB RAM Issue

Many INTEL Chipsets cannot use 4 rank or 8 rank memory.

They must be low density 1R /2R or they don't work period end.

The term “rank” was created and defined by JEDEC, the memory industry standards group. On a DDR, DDR2, or DDR3 memory module, each rank has a 64-bit wide data bus.  In its simplest form, a DIMM with DRAM chips on just one side would contain a single 64-bit chunk of
 data and would be called a single- rank (1R) module.  DIMMs with chips on both sides often contain at  least two 64-bit chunks of data and are referred to as dual-rank (2R) modules.  Some DIMMs can have DRAM chips on both sides but are configured so that they contain two 64-bit data chunks on each side—four in total—and are referred to as quad-rank (4R) modules.


Report Unresolved Customer Service Issues
here

I do not work for Dell. I too am a user.

The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support






Get Support on Twitter @DellCaresPro

0 Kudos
j-sellick
Copper

RE: OptiPlex 980 16GB RAM Issue

Just so you don't feel all alone, I too have just discovered this issue.  I consider myself pretty technically savvy, but it took me a couple of days to get my head around what was even happening here.  Especially since the the system happily recognizes all 16GB of RAM from the BIOS and diagnostic perspectives.  My only guess at this point is that it has something to do with what model of CPU is installed in the system.  You mention "other OptiPlex 980 models" that function correctly with the 4GB DIMMS, so perhaps you could check/test that theory?  I unfortunately do not have access to any 980s with i7 processors, or I would experiment further myself.  Just a thought...good luck, and I will post more if I get any sort of answer.

0 Kudos
xqzit
Bronze

RE: OptiPlex 980 16GB RAM Issue

Yes, I agree with J-Sellick. It might be the processor check if you have the same processors in other 980 models. If you have it then test the 4GB modules in that system else install a different processor in the non-working system and test the 4GB modules.

Sometimes the rank might be an issue too but it's highly unlikely considering other systems recognizing the same 4GB modules.

Looking forward to your post.

0 Kudos

RE: OptiPlex 980 16GB RAM Issue

I also have the same problems, too.

0 Kudos
candkone
Copper

RE: OptiPlex 980 16GB RAM Issue

I have the same problems too. Just bought 2 x 4GB RAM to replace the existing 2 X 2GB chips. I have tried every possible combination but PC failed to boot successfully.

I'm thinking of returning the PC as I really wanted to run 8GB of RAM.

Actually spoke with Dell regarding the 980 Small Form Factor and I don't think the PC would go higher than 4GB RAM.

Any help.

0 Kudos
speedstep
Diamond

RE: OptiPlex 980 16GB RAM Issue

There are no ram ISSUES other than non compatible Ram.

YOU CANNOT USE 8 GIG Modules.  Absolute MAX RAM is 16 gig using 4 X  4 gig Modules.


There are Several Generations of Core I3 I5 I7 processor that ONLY SUPPORT 8 Gigs total.

The Memory Controller hub as well as the GPU are inside the CPU housing so this cannot be changed.

This is also why INTEL says

Max Memory Size (dependent on memory type)

which can be

8Gig or 16 gig or 24 gig or 32 gig max Based on the CPU.

DDR3 PC3-12800 • 9-9-9-24 • Unbuffered • NON-ECC • DDR3-1600 • 1.35V •  512 Meg x 64 •



Report Unresolved Customer Service Issues
here

I do not work for Dell. I too am a user.

The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support






Get Support on Twitter @DellCaresPro

CEG3
Bronze

RE: OptiPlex 980 16GB RAM Issue

I started a new thread this weekend in desktop computers and I too have an older 980 with the i5 650 Intel chip.  I tried 4 x 4 GB of 1600 speed ram and 4 x 4 GB of 1333 and in neither case would the machine reach the desktop, though when you get to the BIOS it shows the RAM and 1333 speed.  The machine works fine with 4 x 2 GB 1333 memory, though.

I did see on the Intel site that the ram recommended includes the slower 1066, so I wonder if that would work at 4 x 4 GB in these machines.  I am twice bitten shy to order any more memory at this point.

0 Kudos
speedstep
Diamond

RE: OptiPlex 980 16GB RAM Issue

DDR3 1066 = (PC3 8500)  too slow

DDR3 1333 (PC3 10600)  too slow

DDR3 1600 (PC3 12800)  This is the REQUIRED Speed for loading 16 Gigs of ram and it must be LOW Density.

DDR3 PC3-12800 • 9-9-9-24 • Unbuffered • NON-ECC • DDR3-1600 • 1.35V •  512 Meg x 64 •

Many INTEL Chipsets cannot use 4 rank or 8 rank memory.

They must be low density 1R /2R or they don't work period end.

The term “rank” was created and defined by JEDEC, the memory industry standards group. On a DDR, DDR2, or DDR3 memory module, each rank has a 64-bit wide data bus.  In its simplest form, a DIMM with DRAM chips on just one side would contain a single 64-bit chunk of
 data and would be called a single- rank (1R) module.  DIMMs with chips on both sides often contain at  least two 64-bit chunks of data and are referred to as dual-rank (2R) modules.  Some DIMMs can have DRAM chips on both sides but are configured so that they contain two 64-bit data chunks on each side—four in total—and are referred to as quad-rank (4R) modules.

 


Report Unresolved Customer Service Issues
here

I do not work for Dell. I too am a user.

The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support






Get Support on Twitter @DellCaresPro

0 Kudos
CEG3
Bronze

RE: OptiPlex 980 16GB RAM Issue

But I already tried this G.Skill memory from Newegg.

www.newegg.com/.../Product.aspx

0 Kudos