Willem,
please note that you use 1.6TB Intel S3520 endurance rating in your calculations but then compare prices with 480GB model, which has only 945TBW or 1.1DWPD ( https://ark.intel.com/products/93026/Intel-SSD-DC-S3520-Series-480GB-2_5in-SATA-6Gbs-3D1-MLC ). It also worth to notice that S3710 has tremendously higher write speed\IOPS and especially SYNC writes. Haven't seen S3520 real sync write tests yet but don't think they differ much from S3510 ones.
Best regards,
Best regards,
Vladimir
2017-05-02 21:05 GMT+05:00 Willem Jan Withagen <wjw@xxxxxxxxxxx>:
On 27-4-2017 20:46, Alexandre DERUMIER wrote:
> Hi,
>
>>> What I'm trying to get from the list is /why/ the "enterprise" drives
>>> are important. Performance? Reliability? Something else?
>
> performance, for sure (for SYNC write, https://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to- )test-if-your-ssd-is-suitable- as-a-journal-device/
>
> Reliabity : yes, enteprise drive have supercapacitor in case of powerfailure, and endurance (1 DWPD for 3520, 3 DWPD for 3610)
>
>
>>> Also, 4 x Intel DC S3520 costs as much as 1 x Intel DC S3610. Obviously
>>> the single drive leaves more bays free for OSD disks, but is there any
>>> other reason a single S3610 is preferable to 4 S3520s? Wouldn't 4xS3520s
>>> mean:
>
> where do you see this price difference ?
>
> for me , S3520 are around 25-30% cheaper than S3610
I just checked for the DCS3520 on
https://ark.intel.com/nl/products/93005/Intel-SSD-DC- S3520-Series-1_6TB-2_5in-SATA- 6Gbs-3D1-MLC
And is has a TBW of 2925 (Terrabytes Write over life time) = 2,9 PB
the warranty is 5 years.
Now if I do the math:
2925 * 104 /5 /365 /24 /60 = 1,14 Gbyte/min to be written.
which is approx 20Mbyte /sec
or approx 10Gbit/min = 0,15 Gbit/sec
And that is only 20% of the capacity of that SATA link.
Also writing 20Mbyte/sec sustained is not really that hard for modern
systems.
Now a 400Gb 3710 takes 8.3 PB, which is ruffly 3 times as much.
so it will last 3 times longer.
Checking Amazone, I get
$520 for the DC S3710-400G
$300 for the DC S3520-480G
So that is less than a factor of 2 for using the S3710's and a 3 times
longer lifetime. To be exact (8.3/520) / (2,9/300) = 1.65 more bang for
your buck.
But still do not expect your SSDs to last very long if the write rate is
much over that 20Mbyte/sec
--WjW
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