[SOLVED] 2x4GB 2133 CL14 + 2x8GB 2133 CL15 | Only showing 16GB

Aug 18, 2020
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jorgeff.com
Hello.
I tried to find a similar case but I had no luck with any solution. Maybe someone could help me.


I've been using 2x4GB 2133 CL14 DIMMS (KHX2133C14D4)
cpu-z_4gb_dimm.png

(Slot #2 and #4 are the same)

Today I installed 2 new DIMMS but this time they are 2x8GB 2133 CL15 (CMV8GX4M1A2133C15)
cpu-z_8gb_dimm.png

(Slot #1 and #3 are the same)

CPU-Z recognize them and shows a total of 24GB
cpu-z_all.png



But Windows 10 is showing only 16GB
windows.png



BIOS also shows all of them but only using 16GB
UEFI-basic-info.jpeg



I tried to change "DRAM CLK Period" from Auto to 14 but I got and error at POST Screen.
UEFI-advanced-info.jpeg



POST Screen Error (I reverted the changes after this)
POST-error.jpeg



The old ones (2x4GB) have a XMP Profile and I selected it (14-14-14-35).

This time it worked (since it changed more options, not like me) but still the same result: 16GB


------

Can anyone guess what's happening here? Is the system automatically only using the new ones (2x8GB)?
They may not be compatible but the system is working as expected so I have hope someones got an answer for me.

Actually, I don't even mind using only 16GB (2x8GB) but if I could, I'd like to have all of them gigabytes.

PS: Here's the full CPU-Z report.
 
Last edited:
Solution
By looking more closely to the CPU-Z output, we see that JEDEC #6 for the Corsair looks very similar (when it comes to the timings but at a lower frequency) to the Kingston JEDEC #5.
Look if by switching the place of the sticks you can enable manually an XMP profile for the Corsair with JEDEC #6; try the boot.
But if by miracle this should work, your RAM will function at 2066 MHz.
As for your image above, I do also understand that both channels work at a CL 15, but I am really not familiar with the Asus Bios, as I have only Gigabytes boards

I switched the DIMMS with no luck.

Then, I updated my BIOS from v2002 to v3805 and it automatically recognized and configured the 24GB...

Sorry for not trying this before asking...
Hello.
I tried to find a similar case but I had no luck with any solution. Maybe someone could help me.


I've been using 2x4GB 2033 CL14 DIMMS (KHX2133C14D4)
cpu-z_4gb_dimm.png

(Slot #2 and #4 are the same)

Today I installed 2 new DIMMS but this time they are 2x8GB 2033 CL15 (CMV8GX4M1A2133C15)
cpu-z_8gb_dimm.png

(Slot #1 and #3 are the same)

CPU-Z recognize them and shows a total of 24GB
cpu-z_all.png



But Windows 10 is showing only 16GB
windows.png



BIOS also shows all of them but only using 16GB
UEFI-basic-info.jpeg



I tried to change "DRAM CLK Period" from Auto to 14 but I got and error at POST Screen.
UEFI-advanced-info.jpeg



POST Screen Error (I reverted the changes after this)
POST-error.jpeg



The old ones (2x4GB) have a XMP Profile and I selected it (14-14-14-35).

This time it worked (since it changed more options, not like me) but still the same result: 16GB


------

Can anyone guess what's happening here? Is the system automatically only using the new ones (2x8GB)?
They may not be compatible but the system is working as expected so I have hope someones got an answer for me.

Actually, I don't even mind using only 16GB (2x8GB) but if I could, I'd like to have all of them gigabytes.

PS: Here's the full CPU-Z report.
Problem is relatively simple: the timings of your 2 kits are different (th CL values and the values below on the SPD tabs in CPU-Z). The PC won't be able to use together these 2 kits.
The Corsair kit is in fact "slower" than the Kingston (the higher the CL number the "slower" the RAM).
Try to enter manually in the bios the values used by the Corsair kit for the Kingston kit (in fact try to slow down the Kingston) . Save in Bios. Try to boot
 
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Aug 18, 2020
4
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20
jorgeff.com
Problem is relatively simple: the timings of your 2 kits are different (th CL values and the values below on the SPD tabs in CPU-Z). The PC won't be able to use together these 2 kits.
The Corsair kit is in fact "slower" than the Kingston (the higher the CL number the "slower" the RAM).
Try to enter manually in the bios the values used by the Corsair kit for the Kingston kit (in fact try to slow down the Kingston) . Save in Bios. Try to boot

Thanks. That's the first thing that I tried but apparently my BIOS Utility only allows me to change "DRAM CLK Period" But all other options like "CAS#Latency", "DRAM RAS# to CAS# Delay", "RAS# ACT Time", etc are set on "AUTO" and I can't change them. (Picture bellow) I can only change those values by selecting an XMP Profile from the 4GB 14CL DIMMS. If I do that, the system boots with 16GB and I don't know how since the 2x8GB are 15CL and not 14CL...

Tomorrow I'll try to swap memory slots (I'll use 1&3 for 4GB ones and 2&4 for 8GB ones) and see if the system still uses 16GB or it uses only 8GB.

I can't change those values (red squared) but doesn't the green squared numbers mean that both channels (A and B) are working at the same speeds already?
change.jpeg


Thanks again for reading me.
 
Thanks. That's the first thing that I tried but apparently my BIOS Utility only allows me to change "DRAM CLK Period" But all other options like "CAS#Latency", "DRAM RAS# to CAS# Delay", "RAS# ACT Time", etc are set on "AUTO" and I can't change them. (Picture bellow) I can only change those values by selecting an XMP Profile from the 4GB 14CL DIMMS. If I do that, the system boots with 16GB and I don't know how since the 2x8GB are 15CL and not 14CL...

Tomorrow I'll try to swap memory slots (I'll use 1&3 for 4GB ones and 2&4 for 8GB ones) and see if the system still uses 16GB or it uses only 8GB.

I can't change those values (red squared) but doesn't the green squared numbers mean that both channels (A and B) are working at the same speeds already?
change.jpeg


Thanks again for reading me.
By looking more closely to the CPU-Z output, we see that JEDEC #6 for the Corsair looks very similar (when it comes to the timings but at a lower frequency) to the Kingston JEDEC #5.
Look if by switching the place of the sticks you can enable manually an XMP profile for the Corsair with JEDEC #6; try the boot.
But if by miracle this should work, your RAM will function at 2066 MHz.
As for your image above, I do also understand that both channels work at a CL 15, but I am really not familiar with the Asus Bios, as I have only Gigabytes boards
 
Last edited:
  • Like
Reactions: Hache_raw
Aug 18, 2020
4
0
20
jorgeff.com
By looking more closely to the CPU-Z output, we see that JEDEC #6 for the Corsair looks very similar (when it comes to the timings but at a lower frequency) to the Kingston JEDEC #5.
Look if by switching the place of the sticks you can enable manually an XMP profile for the Corsair with JEDEC #6; try the boot.
But if by miracle this should work, your RAM will function at 2066 MHz.
As for your image above, I do also understand that both channels work at a CL 15, but I am really not familiar with the Asus Bios, as I have only Gigabytes boards

I switched the DIMMS with no luck.

Then, I updated my BIOS from v2002 to v3805 and it automatically recognized and configured the 24GB...

Sorry for not trying this before asking here: I've always been scared of updating the BIOS
 
Solution