Re: Very poor read performance, query independent

Mark,

I received yesterday a second server having 16 drives bays. Just for a
quick trial, I used 2 old 60GB SSD (a Kingston V300 and a ADATA SP900) to
build a RAID0. To my surprise, my very pecky RAID controller (HP P410i)
recognised them without a fuss (although as SATAII drives at 3Gb/s. A quick
fio benchmark gives me 22000 random 4k read IOPS, more than my 5 146GB 10k
SAS disks in RAID0). I moved my most frequently used index to this array
and will try to do some benchmarks.
Knowing that SSDs based on SandForce-2281 controller are recognised by my
server, I may buy a pair of bigger/newer ones to put my tables on.

Thanks!

Charles

On Sat, Jul 15, 2017 at 1:57 AM, Mark Kirkwood <
mark(dot)kirkwood(at)catalyst(dot)net(dot)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/