Problem with RAM upgrade on Precision 3660 Tower

@Baldwin PL​ 

I highly suggest staying away from KVR RAM.  It's hit or miss in Dell's.  Their other RAM is ok.

RAM specs and matrix are in the Precision 3660 Tech Guide.

@MWC Tech​ sorry for the old reply.  Is this in a T3660 i7-12700?  I bought 2 HMCG78MEBUA084N and they error out.

@DELL-Cares​

Dear Dell Team, is there already a fix for this common problem? have the same issue - Crucial 32GB CT2K16G4DFRA32A - is not working after RAM upgrade at a Precision 3650 Tower.

Best, Stevie

If it hasn't been mentioned in this thread already:

Crucial hasn't been working in some newer Dell's.  Known working brands::

1. Micron (Though they make Crucial)
2. Dell
3. Samsung
4. Hynix (Dell has often used for their OEM)

Resurrecting this thread to say I had the same problem with Crucial RAM (CT32G56C46U5, 32GB DDR5-5600 UDIMM non-ECC) in a Precision 3680.

They wont work, when they manage to boot to Windows, it shows a lot of blue screens. Very unstable.

I´m going to try the Kingston KCP548UD8-32.

Kingston RAM is ok as long as it isn't KVR (Kingston Value RAM).  KVR has been hit or miss in Dell's.

@iridium21​ in my case it worked after updating the Bios and resetting CMOS battery.

@space-hustle​ Thanks for the tip! I just ordered 2 sticks of 32GB from them based on the rec. 

@stefan kummer​ Would you mind sharing what RAM you were specifically using in this case and if you had the same model Precision? Hoping it's the crucial kit and the same Precision 3660. Would be nice to find out that DELL updated their BIOS to allow the memory layout to be more flexible.

We also have a DELL Precision 3600 and recently tried to bump up from the existing 32gb of ram (2x16gb Micron DDR5-4800 UDIMM chips, in slots 1 & 2) to a full 4x32gb Curcial DDR5-5600 UDIMMs, expecting the RAM to just downgrade itself in speed as needed to. However, we got this same 2 + 5 orange/amber flashing power led light error and no boot-up image. I switched back to the prior RAM setup and then read through all of the BIOS updates and found that 2.23.0 looked very promising (as of this writing, 2.27.2 is the latest, and our Precision was on 2.6.1) as it has this line in the "Fixes and Enhancements" > "Enhancements" sections:

Enhancements:
- Improved the speed of the DDR5 memory.

(Warning, in my experience running this update from the BIOS boot up menu (f12) I did NOT get any progress of the BIOS update applying and just had to be patient while I got not screen info for at least 10-20 minutes, then it finally showed life and the DVD drawer and the HD light showed action and THEN I saw the DELL logo)

Sure enough, with this 2.23.0 BIOS I was able to get 2 of the crucial RAM UDIMMs (2x32gb) to work (had to give it the usual 5 mins or so for it to "train" the RAM or whatever it does) and then I added the other 2 UDIMMs and that worked as well, bringing the system to an awesome max of 128gb of RAM for just under $300. 

Thanks for everyone's contributions on this thread. Hopefully this comment helps someone else. (I would also recommend checking out 2.26.0, which I have not done yet, as it looks like it has some interesting additions for CPU/Memory options:
- Added the Thermal Management and CPU/Memory Zone options under the Power settings in the BIOS Setup.)

Specifics on the RAM we ordered (2 of these):
Crucial 64GB Pro DDR5 5600 MHz Memory Kit CR64KUD56C47

I can confirm that, with the latest BIOS this SK Hynix kit (2x 32GB ECC DDR5-4800) works in either the two stick (64 GB total) or 4 stick (128 GB) configuration.

SK HYNIX Memory || HMCG88MEBEA - SK Hynix 1x 32GB DDR5-4800 ECC UDIMM PC5-38400E Dual Rank x8 Module
https://memory.net/product/hmcg88mebea-sk-hynix-1x-32gb-ddr5-4800-ecc-udimm-pc5-38400e-dual-rank-x8-module/

With a single pair, the system sets the speed to 4400 MT/s. 
With two pairs, the system sets the speed to 3600 MT/s.

Unfortunately, a single stick costs $404, and seems to go up significantly daily/weekly.

I know this is old, but I recently had the same problem installing Crucial RAM on my 3660. I received the amber/white flashing lights upon initial install. After lots of troubleshooting and memory swaps I narrowed the issue down to a BIOS update. I was on BIOS version 2.6.1 but upgraded to the recent Precision_3660_2.31.0 firmware with the driver installer from Dells site and it fixed the problem. I was able to use 2x Crucial 32GB memory for a total of 64GB. 

Hope this helps. 

I have same problem, and i found a method to resolve it.

Resolution: put 32G  * 2 crucial RAM on slot 3 and slot 4

Result:

BankLabel DeviceLocator Manufacturer PartNumber                     SerialNumber    Capacity Speed Configur
                                                                                                   edClockS
                                                                                                       peed
--------- ------------- ------------ ----------                     ------------    -------- ----- --------
          DIMM3         859B0000802C CT32G48C40U5.M16A1             E7A6F687     34359738368  4800     4000
          DIMM4         859B0000802C CT32G48C40U5.C16A1             E7774EDA     34359738368  4800     4000

=========================

Model: T3660, manufacture in 2022 (important , early t3660 not support 4800MHz, max speed is 4400MHz, maybe newer date T3660 could support real 4800MHz)

BIOS: other post had said  need latest bios, MY version is 2.37.1

=========================

Diagnose 1: only put the old 8G RAM on slot 1, and reboot into bios, found 4400MHz;

Diagnose 2: only put one 32G RAM on slot 1, and pc should accept it, speed 4400MHz . If can't , doom;

Diagnose 3: put two 32G RAM on slot 3/4, and pc should accept it, speed 4000MHz

=========================

I tried different combinations

(slot1: 32G) (slot2: 32G) (empty)(empty): fail, 2 + 4 orange/amber flashing

(slot1: 32G) (empty) (slot3: 32G)(empty): fail, 2 + 4 orange/amber flashing

this combination will work, but speed too slow:

(slot1: 8G) (slot2: 8G) (slot3: 32G)(slot4: 32G): ok, but speed is 2000MHz

Good luck to you all