03-03-2014 09:32 PM
I agree, but as it is the only thing that works for me at the moment it is what I'm doing. I would really like to hear a response from Lenovo about this issue. How would I go about getting an official response?
03-04-2014 01:02 AM - edited 03-04-2014 01:14 AM
1866 CL10 has lower latency compared to 1600 CL9. See my Excel sheet:
You realize that 1866MHz memory is not officially supported by Haswell. Installing faster memory may require more VTT/VCCIO voltage which you cannot change in laptops. What I am trying to say here is, that it is possible that the memory controller of your CPU may need more voltage to run those memory modules.
If the BIOS is not an issue here, I would grab a new CPU. Maybe the chip lottery will eventually give you one that is able to run 1866MHz memory.
To summarize, there is no such thing as guaranteeing compatability.
My advice is, don't try to hold on to it, grab some 1600MHz CL9 RAM unless you use 7zip a lot. You don't want to stress the memory controller of the CPU, down the road you will eventually run in instabilities. I know some people here claim they don't have had any issues. But I think we can all agree memory reliability is more important over having faster RAM. Unless you want to see all your precious data corrupt.
Personal website: ThinkScopes
03-04-2014 01:27 PM - edited 03-04-2014 01:37 PM
I upgraded by adding 3 Crucial 8gb p/n CT102464BF160B, and the system appears to work fine for the last 7-10 days with a full 32gb. The 4th original chip is in the machine. Using a DataRAM 'RAM' disk in the memory. Works GREAT!
BTW, I'm selling my unit. See Craigs List, NJ listings. The unit is ~one week old. 20BG0016US
03-04-2014 08:05 PM
03-04-2014 09:30 PM - edited 03-04-2014 09:31 PM
Check the QVL on the vendor's site:
No W540 there . . .
03-05-2014 08:09 AM
Great advice. Thanks for the informative spreadsheet. I wish the 1866 CL10 worked, but its good to know that there's only a small difference between it and 1600 CL9... 10.72 ns / 11.25 ns = .953
03-07-2014 10:59 AM - last edited on 03-07-2014 12:57 PM by andyP
It's really hard to find information on memory compatibility, but for those that are looking, I can confirm that the Corsair Vengeance CMSX16GX3M2B2133C11 modules work fine at 1866mhz C11. I ran the extended memory test in the BIOS and it passed all tests.
For those that do install aftermarket memory, I noticed that the POST takes a long time on the first boot. Mine showed a blank screen for literally 10 seconds before the Lenovo logo popped up. I was bummed out and thought that I would have to go through the process of RMAing my memory.
My memory sticks are sold as 2133mhz capable. For those that are wondering, no it will not go to those speeds. Sure there was a $20 premium across 4 sticks, but I really don't care considering the overall cost of the laptop. I'm no RAM expert, but it would seem reasonable to say that RAM tested at 2133mhz should be rock solid at 1866mhz. Corsair also sells 1866mhz of the same brand, so for anyone looking to save a few bucks, that might be the sweet spot for the W540. I'm posting my CPU-Z images below if anyone is interested.
Moderator note; picture(s) totalling >50K converted to link(s) Forum Rules
03-09-2014 01:55 AM
03-09-2014 08:45 AM - last edited on 03-09-2014 08:49 AM by zoltanthegypsy
I'm on 2.09 and my Mainboard tab can be seen below. Also I should note that my first go at installing my memory caused my computer to not POST. I have no idea what the exact cause was, but let's just say it was a rush job that I did in the trunk of my car before I went into the airport. When I got into the terminal and did a quick test, on battery power, my computer didnt POST. I know I tried cycling the power a few times and I could've sworn I let it sit for a number of seconds before shutting it down. Needless to say, I was disappointed and reverted back to stock memory (I brought my tools and stock memory with me for this exact reason).
Later, at my destination, I wanted to give it one more shot. I made sure I took my time with the install and installed the memory one stick at a time. I had my computer wired into the power outlet this time as well. I booted up my computer, got the same response and just let it sit there with the black screen, me mulling over the next steps. But then the Lenovo logo showed up surprisingly. I incremently added RAM sticks (in case this was some problem with having all 4 sticks installed), and everything worked fine. Each time I added a new stick, I was faced with a long 10-15 second black screen before the Lenovo logo came up. I know your situation is different already, but I just wanted to note that my own experiences were not without problems.
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03-09-2014 02:16 PM
The computer is going through self diagnostics and reviewing its new configuration. This is normal whenever you add or remove peripherals and in particular, change the memory. In the old days, you could request the BIOS to post the diagnostics, or cut short the memory check.
In this scenario, the more memory you add the longer will be the check.
Not an issue, welcome to the world of treating the consumer/user as dumb.
If you added 32g of memory, look at DataRAM RAM disk, and you could configure some programs to write to the RAM saving some wear and tear on the HD, and also use the RAM to unRAR or unZIP file.