I can't set CAS Latency to 15

Discussion in 'General Hardware' started by AKBLT, Mar 27, 2024.

  1. AKBLT

    AKBLT Member

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    Hello. I use MSI Mag X570S Torpedo Max motherboard with Corsair Vengeance LPX (4x8) 32 GB Ram and I set to CAS latency 15 in BIOS and my PC opening without any issue but on Windows 11 when I checked with HWInfo64 I saw CAS latency as 16 instead of 15. Anyone have idea why it shows CAS latency as 16 when I set it as 15?

    Here's HWInfo64 image so you can see memory timings:
    Memory timings.png
     
  2. RealNC

    RealNC Ancient Guru

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  3. Horus-Anhur

    Horus-Anhur Ancient Guru

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    Do you have GDM enabled?
     
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  4. AKBLT

    AKBLT Member

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    Here's results of ZenTimings if I see right still CAS latency is 16 also as you see GDM enabled, I can try to disable GDM if this is necessary:
    ZenTimings.png
     

  5. Horus-Anhur

    Horus-Anhur Ancient Guru

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    GDM only allows using even numbers.
    You can try GDM off and 2T on. That is how I run mine.
     
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  6. AKBLT

    AKBLT Member

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    Thank you so much. After settings GDM off and 2T, CAS latency turned to 15 by the way is there any major differences between of 2T and 1T? I thought 1T better but I'm not expert so I'd like to know if 2T better.
    Finally.png
     
  7. RealNC

    RealNC Ancient Guru

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    1T is faster. Try it but prepare a memtest86+ boot USB stick first to test it. (I don't recommend booting to Windows if you're not sure memory is stable first, due to the chance of memory errors resulting in garbage being written to storage.)
     
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  8. AKBLT

    AKBLT Member

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    Hmm I also heard there's TestMem5 program for testing is this any good? I can try memtest86+ of course but I want to learn if TestMem5 program is more stable/better?
     
  9. Horus-Anhur

    Horus-Anhur Ancient Guru

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    In terms of performance, if properly configured, they are about the same.
    But you can test it. For example, try Benchmate. Y-cruncher 0.8 is sensitive to memory bandwidth. While PyPrime is sensitive to memory latency.
    AIDA64 can also be used to check for memory performance.

    For stability. Y-cuncher is very good for that. Also TM5 with 1Usmus config or Anta777 Extreme config.
     
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  10. aufkrawall2

    aufkrawall2 Ancient Guru

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    Not seeing any performance difference in games between CR1, GDM and CR2. But I know that CR1 instability is a random b*tch to test, so imho just go CR2 and be happy when RAM is stable with otherwise fast timings that actually matter. Though I also found CL15 hitting similar clock walls like 14.
     

  11. Horus-Anhur

    Horus-Anhur Ancient Guru

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    Lowering CAS from 16 to 15 will probably do little for performance.
    I don't know what die those chips are. But there is more to gain by lowering tRFC, tRC, TFAW and tRRDS and TRRDL
     
  12. RealNC

    RealNC Ancient Guru

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    To use TestMem5 you need to boot into Windows. Which I don't recommend until you can pass a memtest86+ first (which does not require any OS, it boots directly off a USB stick.)

    You can only let it run for like 5 minutes or so, for a quick sanity test of your RAM if you intent to do a full TestMem5 test afterwards.
     
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  13. AKBLT

    AKBLT Member

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    Sorry for late response. I just tried memtest86+ with writing to USB then reboot my PC but in boot menu I couldn't see any extra option for memtest86+ do you know if there's extra thing I should enable on BIOS for seeing memtest86+ boot option?
     
  14. RealNC

    RealNC Ancient Guru

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    On my BIOS (MSI,) I need to add the USB stick first in the boot options, then when the PC boots and the motherboard logo shows up, I need to press F11 to get a boot menu where I select the USB stick.
     
  15. AKBLT

    AKBLT Member

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    I just did that already but still in boot menu my USB doesn't show up, there was no issue when I install Windows so its not related to USB just in case I'm saying giving this information.
     

  16. RealNC

    RealNC Ancient Guru

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    No idea then. Always worked for me.
     
  17. Did you make a bootable USB stick? Just copying memtest files isn't enough I think.
     
  18. AKBLT

    AKBLT Member

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    I did also RealNC said memtest86+ not normal memtest but I can try this one aswell if you want? And see if this will appear on boot menu.
     
  19. insp1re2600

    insp1re2600 Ancient Guru

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    leave gdm enabled, its often referred to as cas 1.5.

    lower your voc to 1.250, mem controller might be sweating.

    if b-die, id try cl14, what actual memory is it? looking at model number it appears to be c18 3600's so you may struggle to get 15 / 14 anyway. i doubt that would be samsung , more like hynix.

    have you upped the memory voltage? dont go above 1.6 unless using memory cooling fans or water.
     

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