Confused about SSD benchmarks

Discussion in 'MacBook' started by vistadude, Feb 16, 2013.

  1. vistadude macrumors 65816

    Jan 3, 2010
    I have a white macbook 2009 unibody with 8 GB RAM. I just upgraded to mountain lion and windows 7 64 bit. I bought a Samsung 840 SSD (non pro) and I realize my motherboard is limited to SATA 2 speeds. When I run Samsung Magician's version 4 software, the benchmarks records about 200 MB write and read speed, which sounds okay if the theoretical limit is 375 MB/sec for SATA 2. But the IOPS performance is confusing. It's a lot slower than what the drive is capable of. Can someone look at my screenshot and provide some guidance on this? My real world performance copying a 900 mb file to desktop obtained about 150 mb/sec speed, which sounds pretty good to me, but I'm not sure if that's slow or not.

    Btw, I did all of the performance and OS tweaks the Magician software recommended, and it hardly affected performance (made it worse by a little). Also Magician reports that AHCI is not enabled, it can't detect the SATA Interface, and looking through the Windows registry, TRIM seems to be off. But Samsung's software doesn't provide a way to turn it on, and AHCI seems to require a master boot record edit to enable.

    Thanks in advance.

    Attached Files:

  2. paul-n macrumors regular

    Jul 12, 2012
    Your values for sequential read and write are ok, due to 8/10 code the maximum throughput would be 300 MB/s and real world is around 250 MB/s.
    The IO issue is maybe your old computer, which maybe is not capable for more IOs.
    You can try AS SSD if you want to try another benchmark.

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