Subject: Re: Very poor read performance, query independent
To: Charles Nadeau <charles.nadeau@gmail.com>
Cc: "pgsql-performa." <pgsql-performance@postgresql.org>
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From: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
Message-ID: <70ce3831-fe97-fd63-35ec-a0f5b6e5f31b@catalyst.net.nz>
Date: Sun, 16 Jul 2017 11:48:08 +1200
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Right, that is a bit of a show stopper for those SSD (the Intel needs 
SATA 6Gb/s and the Sammy's need PCIe 3.0 to perform to their rated specs).

regards

Mark


On 16/07/17 04:12, Charles Nadeau wrote:
> Mark,
>
> The server is a . It doesn't really work with SATA drives. And when 
> you find one that is compatible, it is only used at 3Gb/s with a 
> maximum of 50000 IOPS (a well know caracteristic of the HP P410i SAS 
> RAID controller). I am looking at getting a Kingston Digital HyperX 
> Predator that I could use in one of the PCIe 2.0 x4 slot. However I am 
> worried about the "thermal runaway", i.e. when the server can't get a 
> temperature reading from a PCIe card, it spins the fans at full speed 
> to protect the server against high temperature. The machine being next 
> to my desk I worry about the deafening noise it will create.
> Thanks!
>
> Chales
>
> On Sat, Jul 15, 2017 at 1:57 AM, Mark Kirkwood 
> <mark.kirkwood@catalyst.net.nz <mailto:mark.kirkwood@catalyst.net.nz>> 
> wrote:
>
>     Thinking about this a bit more - if somewhat more blazing
>     performance is needed, then this could be achieved via losing the
>     RAID card and spinning disks altogether and buying 1 of the NVME
>     or SATA solid state products: e.g
>
>     - Samsung 960 Pro or Evo 2 TB (approx 1 or 2 GB/s seq scan speeds
>     and 200K IOPS)
>
>     - Intel S3610 or similar 1.2 TB (500 MB/s seq scan and 30K IOPS)
>
>
>     The Samsung needs an M.2 port on the mobo (but most should have
>     'em - and if not PCIe X4 adapter cards are quite cheap). The Intel
>     is a bit more expensive compared to the Samsung, and is slower but
>     has a longer lifetime. However for your workload the Sammy is
>     probably fine.
>
>     regards
>
>     Mark
>
>     On 15/07/17 11:09, Mark Kirkwood wrote:
>
>         Ah yes - that seems more sensible (but still slower than I
>         would expect for 5 disks RAID 0).
>
>
>
>
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>
>
>
> -- 
> Charles Nadeau Ph.D.
> http://charlesnadeau.blogspot.com/


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