SSD in Linux and trim (“discard”)

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My new workstation is “finished”; I’ve been using it for client work and all seems well. I meant to post interim updates on its progress along with some photos, but got carried away with the build. No doubt I’ll get some photos on here soon.

One minor issue which I resolved (at least for now) last night was annoying pauses in GNU/Linux (Ubuntu), which I use as my main operating system. These roughly second-long pauses in which my mouse input wasn’t actioned seemed to occur particularly often when doing things like switching tabs in Thunderbird’s settings dialogue boxes amongst other things.

They hadn’t always been present, and I was pretty sure they were because of some adjustments I had made to operating system settings on account of using a SSD (solid-state drive), which were intended to increase long-term performance and wear levels. I’d followed most of the tips from these pages:

Following the advice given, I’d enabled TRIM support for my ext4 partition by editing my fstab file. However, after making that and other changes, a process of elimination showed that it was this adding of the ‘discard’ option that had introduced the annoying pauses.

I’m now running without ‘discard’ (TRIM) enabled on my Crucial RealSSD C300. Hopefully the drive will “recover” well enough without TRIM. I’ll also try re-enabling ‘discard’ every time a new kernel is installed to see if this issue gets sorted.

Comments

  1. ultron says:
    18 February, 2011 at 06:55

    Hi David,

    Thanks for posting pictures of your build.

    Did you have any problem with clearance between the frio cooler and the RAM?
    I’ve been considering building the exact same system, but read that the frio might not fit if all 4 RAM slots were filled.

    It would be great if you could post pictures of the motherboard with the RAM and cooler installed.

    Regards,
    Peter

    • David Oliver says:
      18 February, 2011 at 10:58

      Hi Peter,

      Yes, the air intake fan of the Frio does indeed protrude over the nearest RAM slot, meaning that to get four DIMMs in you would need to take the fan off the Frio. I’m not sure how much of a problem that would be, especially if you put a fan the other side of the Frio, as I believe Sandy Bridge CPUs run pretty cool. But if I were building again I’d be looking for a different cooler.

      I’ll get my other snaps up sometime, but in the meantime here are a couple I’ve uploaded to Dropbox.

      I’ve got three Corsair Vengeance DIMMS which I put in the other three slots. I think I made a (schoolboy!) error when buying that Corsair kit as it’s meant for motherboards with three memory channels and my Asus P8P67 Deluxe is dual channel. It’s strange – sometimes the BIOS recognises 12GB, but more often 8GB. Do you know whether or not I could buy a fourth DIMM of the same RAM to put in the remaining slot to use 16GB? It’s not a problem at the moment – maybe I should just take one DIMM out.

      • ultron says:
        2 March, 2011 at 10:38

        I’m not an expert, but I believe you should buy ram in matching pairs. Buying a 4x4GB would be safest if you want 16GB. You might get away with just adding one more stick.

    • David Oliver says:
      18 February, 2011 at 11:09

      I forgot to ask: do you already know about the Intel SATA issue which can potentially affect the SATA 2.0 (3Gbp/s) ports on the motherboards with these chipsets? I’m okay because the Asus comes with an additional controller for extra SATA 2.0 ports which should be unaffected.

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