DDR3L into DDR3 Slot

Wolf456

Reputable
Aug 9, 2014
2
0
4,510
Hi. I've just bought some memory into my Lenovo G580 notebook. The module supposed to be an old school DDR3 but turned out as a DDR3L module (1.35V/1.5). I did not find exact info if my motherboard supports DDR3L, but I ran a memtest for a day, and it seems ok. Could someone tell me if it is going to work fine at long term, or I am going to fry something?

The module runs on 665.2MHz currently. I'm not familiar with timings, but I presume the slight difference between the two modules won't be a problem.

TECHNICAL INFO

Motherboard: Lenovo 20157 (Lenovo Emerald Lake 2)
North Bridge: Intel Sandy Bridge-MB IMC

New module:
Module Name Crucial ST102464BF160B.16F
Manufacture Date Week 44 / 2012
Module Size 8 GB (2 ranks, 8 banks)
Memory Speed DDR3-1600 (800 MHz)
Module Width 64 bit
Module Voltage 1.35 V / 1.5 V
Error Detection Method None
Refresh Rate Normal (7.8 us)
DRAM Manufacturer Micron

Memory Timings:
@ 800 MHz 11-11-11-28 (CL-RCD-RP-RAS) / 39-240-5-12-6-6-24 (RC-RFC-RRD-WR-WTR-RTP-FAW)
@ 761 MHz 10-10-10-27 (CL-RCD-RP-RAS) / 37-229-5-12-6-6-23 (RC-RFC-RRD-WR-WTR-RTP-FAW)
@ 685 MHz 9-9-9-24 (CL-RCD-RP-RAS) / 33-206-5-11-6-6-21 (RC-RFC-RRD-WR-WTR-RTP-FAW)
@ 609 MHz 8-8-8-22 (CL-RCD-RP-RAS) / 30-183-4-10-5-5-19 (RC-RFC-RRD-WR-WTR-RTP-FAW)
@ 533 MHz 7-7-7-19 (CL-RCD-RP-RAS) / 26-160-4-8-4-4-16 (RC-RFC-RRD-WR-WTR-RTP-FAW)
@ 457 MHz 6-6-6-16 (CL-RCD-RP-RAS) / 22-138-3-7-4-4-14 (RC-RFC-RRD-WR-WTR-RTP-FAW)

Old module:
Module Manufacturer: Samsung
Module Part Number: M471B5173BH0-CK0
Module Manufacturing Date: Year: 2013, Week: 13
Memory Speed: 800.0 MHz (PC3-12800)
Module Size: 4096 MBytes
Memory Type: DDR3 SDRAM
Module Nominal Voltage (VDD): 1.5 V

Supported Module Timing at 800.0 MHz: 11-11-11-28
Supported Module Timing at 733.3 MHz: 10-10-10-26
Supported Module Timing at 666.7 MHz: 9-9-9-24
Supported Module Timing at 600.0 MHz: 8-8-8-21
Supported Module Timing at 533.3 MHz: 7-7-7-19
Supported Module Timing at 466.7 MHz: 7-7-7-17
Supported Module Timing at 400.0 MHz: 6-6-6-14
Supported Module Timing at 333.3 MHz: 5-5-5-12



 
Solution
Standard DDR3L Modules should be backwards compatible and accept 1.5V as well.
Looking to the spec that you sent it says:
Module Voltage 1.35 V / 1.5 V

And this is the difference: DDR3L can run with 1.35 as well as with 1.5V ..
so if there is no other incompatibility with your motherboard and the memtest runs fine this should be no Problem.

Hermann


--
Upcoming Events:
=================
"Open the Black Box of Memory"
What you always wanted to know about Memory!
.. But never had the right expert to ask!
September 24./25. 2015 in Copenhagen
vist www.EyeKnowHow.de/en/seminars/

EKH - EyeKnowHow
Hermann Ruckerbauer
www.EyeKnowHow.de
Hermann.Ruckerbauer@EyeKnowHow.de
Itzlinger Strasse 21a
94469 Deggendorf
Tel.: +49 (0)991 / 29 69 29...

ruckb

Distinguished
Feb 11, 2009
7
0
18,520
Standard DDR3L Modules should be backwards compatible and accept 1.5V as well.
Looking to the spec that you sent it says:
Module Voltage 1.35 V / 1.5 V

And this is the difference: DDR3L can run with 1.35 as well as with 1.5V ..
so if there is no other incompatibility with your motherboard and the memtest runs fine this should be no Problem.

Hermann


--
Upcoming Events:
=================
"Open the Black Box of Memory"
What you always wanted to know about Memory!
.. But never had the right expert to ask!
September 24./25. 2015 in Copenhagen
vist www.EyeKnowHow.de/en/seminars/

EKH - EyeKnowHow
Hermann Ruckerbauer
www.EyeKnowHow.de
Hermann.Ruckerbauer@EyeKnowHow.de
Itzlinger Strasse 21a
94469 Deggendorf
Tel.: +49 (0)991 / 29 69 29 05
Mobile: +49 (0)176 / 787 787 77
Fax: +49 (0)3212 / 121 9008
 
Solution


DDR3L modules are backwards compatible with DDR3 by design.

Manufacturers use the same integrated circuits for DDR3 and DDR3L. The highest quality ICs are tested for operating at 1.35 volts and are branded as DDR3L if they run properly. Other than that, there's no difference between them.
 

ruckb

Distinguished
Feb 11, 2009
7
0
18,520
Hello,
yes it is correct, that they should use the same Chips. So from a functionallity point of view it is really just the same compatibility issue as with DDR3 from one vendor to another vendor (or even just for one die shrink to the next die shrink).

JEDEC defines that the DIMM needs to be backward compatible. So if a JEDEC compliant DIMM is operating at 1.5V should be tested and verified from the vendor. But not too many DIMM vendors really state that the DIMM is JEDEC compliant.
E. g. I have seen DIMMs with devices not supporting specific CL that they would need to support to be JEDEC compliant ..

And in this case thre is no need that the DIMM really is backward compatible (even if it is just a question of Speed, or reliability over time).
Even standard DIMMs are theoretically interchangable, there are many compatibility issues between motherboard, controller and DIMM out there .. and DDR3L will not make it better ..

Guess thats the usual difference between theory and praxis ..
and so I prefer to look at the DIMM spec and at least verify that the 1.5V is a supported voltage on a DDR3L DIMM if I intend to use it in a DDR3 System...

Hermann