07-17-2019 02:51 PM - edited 07-17-2019 02:58 PM
So I just purchased a X1 Extreme and I was browsing for RAM and SSD upgrades. I start noticing a CAS Latency listing on all the RAM options and at first had no idea what that meant. So after researching I see that basically it can be from 15 to 19 and that lower is better but that some laptops can't handle the lower CL rating.
So my question, what CL rating can the X1 Extreme handle? It comes with CL 19 RAM stock but if it can handle 15,18 etc I would rather put lower if possible.
EDIT: on a side note if you have a recommendation for a 1-2TB SSD that would be helpful as well. Thanks!
Solved! Go to Solution.
07-18-2019 01:47 AM - edited 07-18-2019 01:59 AM
In order to have lower memory latency , you must have both of them with lower CL rating. So if you want to keep the current CL19 ram, just buy any ram that is cheapper with CL19 and ddr4 2666 such as Crucial 16GB DDR4-2666 SODIMM(CT16G4SFD8266)
Any way, if you want a lower CL ram, HyperX HX426S15IB2K2/32 is what I currently use. detailed information see:
For SSD, samsung 970 evo, or samsung 970 evo plus is even better.
07-18-2019 09:38 AM
Strange. I'm using your exact same memory on my X1E1, yet I don't have the JEDEC DDR4-2666 CL 15-17-17 profile.
To run at CL 15 my X1E selects the XMP #1 profile, which BTW works flawlessly.
07-18-2019 10:05 AM
Well, I think it's just because CPU-Z doesn't show all of the timing table, and JEDEC DDR4-2666 CL 15-17-17 profile is exactly the same of XMP profile XMP #1 profile. From aida64(figure in the first answer) memory timings showed DDR4-2666 CL 15-17-17.
Anyway, the important thing is this one can exactly run at CL15 so that's a good news right?