Dell Precision 7540 and 7740 Owner's Thread

Discussion in 'Dell Latitude, Vostro, and Precision' started by djdigitalhi, Aug 13, 2019.

  1. n0xlf

    n0xlf Notebook Enthusiast

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    Does anyone know or have documentation on the best slots to put multiple SSD drives in for RAID-0? I have 2x2TB 970 Evo Plus drives in RAID-0 that are showing the speed of what one drive would (for sequential read/write - 4K is worse due to the additional latency as would be expected), either because I'm sharing PCI lanes or it's a limitation of the PCH. I did it mostly for the capacity and not speed, but...
     
  2. Hopper82

    Hopper82 Notebook Geek

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    In my case:
    -intel spec calls for 2666Mhz, not anything above. Normally the IMC can handle 3200 or even more, but with full locked (totally new) bios for me was a little risky.
    -in amazon (when I did my order) the gskill 3000 cl16 were priced exactly twice compared to HyperX 2666 cl15. So I preferred 64gb a the cost of 32gb instead of ~ 4Gb/sec more in bandwidth.
     
  3. Aaron44126

    Aaron44126 Notebook Prophet

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    This is something that has been observed with this generation as well as the previous. All of the NVMe slots share PCI lanes. I think when you take the graphics card into account (it is x16), there are only eight lanes left for everything else to share?
     
    Last edited: Aug 30, 2019
  4. Ionising_Radiation

    Ionising_Radiation ?v = ve*ln(m0/m1)

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    Yep, 24 total from CPU = 16 to GPU, 4 to PCH and 4 direct attachments to CPU. Not much to go around, and the NVMe controllers go to the PCH.

    There's really no point in RAID-ing NVMe SSDs on consumer machines.
     
  5. lefty1

    lefty1 Notebook Enthusiast

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    So if all NVMe's share 4 lanes, then it should be no difference where to put first and second NVMe for example?

    I am planning one drive for OS and second for data.

    In that case i could try to find the "coolest" area to place the drives... correct?
     
  6. Don Patrone

    Don Patrone Notebook Enthusiast

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    When i see this comparison, i don't think the rtx 5000 is worth the extra charge.

    How good is the rtx 4000 performance in Games
     
  7. Hopper82

    Hopper82 Notebook Geek

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    Interesting.
    Intel Ark site report 16 pcie lanes for 8th and 9th gen mobile cpu. Where did you find 24?
    Maybe the discrete gpu are setted at 8x by default?

    After reading your comment, I also try to move my 970 Evo Plus from the original slot (the one listed as M2 PCIe SSD #0 in bios) to the other one listed as SATA#0 in bios (slot #5 to slot #6) and the stranges low 4k values that I have in some benchs are now gone. Seems like it's not exactly the same management.
     
  8. lefty1

    lefty1 Notebook Enthusiast

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    16 Lanes for CPU is correct:
    https://www.intel.de/content/www/de...ucts.html/processors?productIds=192990,192987

    only the Intel CM246 chipset can handle up to 24 lanes (max):
    https://ark.intel.com/content/www/us/en/ark/products/135100/mobile-intel-cm246-chipset.html

    That is really interesting...

    As i have read you are also using two NVMe's.
    In what physical position do you have the good results now? #5 and #6 ? 5 for boot and 6 for your data?
     
    Last edited by a moderator: Aug 31, 2019
  9. Hopper82

    Hopper82 Notebook Geek

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    No, I removed the original Micron NVME drive to use it as external drive in a TB (10Gbps) case since it was only 256Gb.
    I only have the 970 2Tb drive onboard, now moved from slot #5 to slot #6.

    Here you can see the difference in 4k performance:
    Slot #5:
    [​IMG]

    Slot #6:
    [​IMG]

    I also verify the consistency in both case with different runs (4-5).
    Also winsat report a better overall performance.
    In crystaldisk no noticeable difference instead.

    Maybe can be something related to windows/benchs too.
     
    Last edited: Aug 31, 2019
    lefty1 likes this.
  10. lefty1

    lefty1 Notebook Enthusiast

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    ok, so #6 is the "good" one... :)

    Now i only have to find a second "good" one... ;)

    Unfortunately i will receive my machine in mid september earliest, so i can not try myself so far.:(


    - the original 256GB i will take as additional spare for my
    personal garbage-collection :)

    By the way: i think we ordered the same configuration....
     
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