12-25-2013 12:13 PM
I'm looking for 4x8GB 1866MHz SO-DIMMs for my Dell Precision M6800 and Crucial memory advisor tool tells me there's guaranteed-compatible memories with product numbers CT4904081 (8GB) and CT4904043 (2x8GB) and there was a notice that compatibility is guaranteed for only those products the tool lists. There are also generic memories with identical looking specs with product numbers BLS8G3N18AES4 (8GB) and BLS2K8G3N18AES4 (2x8GB). The shop I was going to buy those sells only those generic ones.
Then I found this Q&A: http://www.crucial.com/kb/answer.aspx?qid=4589
So basically those product numbers might refer to the exact same memories but can I get a confirmation for that somewhere somehow?
12-27-2013 08:54 AM
Thank you for contacting us today. You should be safe to order BLS2K8G3N18AES4 or 2 of BLS8G3N18AES4 as these are the same as CT4904043 and CT4904081.Basically CT4904043 and CT4904081 are BLS2K8G3N18AES4 and BLS8G3N18AES4 for the Dell Precision M6800. Please let us know if you have any other questions or concerns about these upgrades.
01-19-2014 06:23 AM
Based on this answer and another compatibility confirmation I got from Crucial, I just tried to replace my existing memory with two of those (BLS8G3N18AES4CEU) on my Precision M6800 and the system won't even start! All I get is error code through blinking leds which according to the manual signals that "The memory modules are detected but has encountered an error".
01-20-2014 12:24 PM
I am sorry for the issues that you are experiencing with your RAM. What is the full part number on the modules? This should read something like BLS8G3N18AES4CEU.16FED. Is your system the 2 slot or 4 slot version? Thank you in advance for this information.
01-20-2014 12:35 PM
Package says BLS8G3N18AES4CEU and the modules contain BLS8G3N18AES4.16FER (so that CEU part is not on the modules). My system is the 4 slot Core i7 version.
01-20-2014 03:49 PM
There's a couple of questions I would like to add:
1) Are you able to tell from that part number whether those modules are from an old or new batch?
2) I don't find any memory related settings from the BIOS (memory timings, XMP setting etc.). Do you think it's because they are not actually needed and the system is fully automatic on those? The only possibly related setting I can see is "fastboot", which is by default set to make thorough config and compatibility steps during boot, which sounds right to me.
3) Are you aware of any known cases of those modules working (or not) in Precision M6800 or the previous M6700 model?
01-22-2014 12:12 PM
Thanks for the information.
1) We are able to tell if the RAM is from a batch that has been deemed incompatible with your system. The RAM that you purchased is from a batch that is compatible and has been tested as compatible.
2) These memory modules should be plug and play and should require no adjustments. The timings should read 10-10-10-30 and the voltage should be set to 1.35v.
However, when I looked up your system on Dell's website it does appear that there is a a BIOS update available. This BIOS update can be found here. It might be that this is the issue and a BIOS update may be all that it requires.
3) We have no other known cases of these modules having issues in your system. We do keep track of this data and have sold these modules for your system.
If you are still having issues please contact us using the information in my signature and we would be happy to set up a replacement if needed. Thank you for your patience.
01-22-2014 12:28 PM
Thank you for the responses.
I had already updated to the latest BIOS (A06) before I tried those modules.
I have contacted the shop I bought these from (as it wasn't directly from Crucial) and I'm waiting for their response first. The big question really is whether it's worth trying another set of the same or try something else if possible.
Before I mentioned I tried two of those modules and forgot to add that I actually bought four of them (just tried 2 first) and none of them work, even when tried individually. And when I tried them I had removed all existing mem (factory installed 2*4GB 1600MHz) not to have any mismatches or such. So it just sounds a bit too unlucky to have that many faulty ones, unless there has been some big batch of malfunctioning mem or something bad has happened to them at the shop or in transit or something. At least I didn't see any visible damage anywhere.
01-22-2014 12:40 PM
Yes, it does sound like it's extremely unlikely that they would all be defective. They seem to all install easy enough? They don't seem to beep like they are not quite seated correctly?
Let us know what the shop says. Our warranty would support them but would be part for part replacement.
01-22-2014 12:51 PM
All of them seemed to fit just fine. I was very careful while trying and checked that they were basically as deep in as they could and looked like the existing ones when seated and the side clips also snapped to position just fine. I also tried two of them at primary slots A and B, and at secondary slots C and D and all of them individually at slot A. Every time the result was the same. And the old mems worked just fine after that when I put them back. No sign of any problems with the seating.
The manual lists three different error codes for memories (signaled via leds as that's all the laptop could do with them, nothing on the screen). The possible code descriptions are:
1) The memory modules are detected but has encountered an error.
2) No memory modules are installed/detected.
3) Memory failed to initialize or memory is unsupported.
Of which I got the first one every time. So at least that indicates that the system definitely found something that was installed and it wasn't able to say that they would be unsupported but instead that there was some error with them.