On Sun, Mar 6, 2016 at 3:16 PM, Heath Albritton <halbr...@harm.org> wrote:
>> On Thu, Mar 3, 2016 at 10:17 PM, Christian Balzer <ch...@gol.com> wrote:
>> Fair enough.
>> Sync tests would be nice, if nothing else to confirm that the Samsung DC
>> level SSDs are suitable and how they compare in that respect to the Intels.
>
> I'll do some sync testing next week and maybe gather my other results
> and put 'em on the web somewhere.
>
>
>> Yeah, my curiosity was mostly if there is similar ratio at work here
>> (might have made more sense for testing purposes to REDUCE the
>> overprovisioning of the Intel) and where the point of diminishing returns
>> is.
>
> I don't think you can reduce the over-provisioning below default
> levels.  I've played with the tools from Intel and Samsung and haven't
> seen an option for this.  In fact, the manufacturers aren't very
> forthcoming about the fact that they are doing any over-provisioning.
>
>
>> If I'm reading the (well hidden and only in the PDF) full specs of the
>> 960GB 863 correctly it has an endurance of about 3 DWPD, so the comparable
>> Intel model would be the 3610s.
>> At least when it comes to endurance.
>> Would be interesting to see those two in comparison. ^.^
>
> I could test them side-by-side.  Given the degree with which the SM863
> exceeds the performance of the S3710, I'm not sure the S3610 would
> fare very well.  Frankly, I think some of the limitations are in the
> flash controller.  I'm speculating here based on the spikes I've seen
> on the Intel units that I've tested.

How much difference is there regarding to performance between S3710 and S3610?

>
> As for endurance, the 845DC Pro was rated at 10DWPD.  Again, I was
> disappointed with the 3DWPD of the successor.

Sorry, probably I don't understand this sentence properly.
Do you mean that 10DWPD would not be good successor of 3DWPD which I'm thinking?
Can you elaborate on this more?

>I was reassured by the
> folks at Samsung that with the same level of over-provisioning the
> SM863 would have the same endurance as the 845DC Pro.
>
> Caveat emptor and all that, given that's not really documented
> anywhere.  This makes sense given how wear-leveling works.
>
>>> I think the stock kernel module is 4.x something or other and LSA, now
>>> Avago has released P9 through P12 in the past year.  When I first
>>> started using them, I was on the P9 firmware and kernel module, which
>>> I built from the sources they supply.  At this point most of my infra
>>> is on the P10 version.  I've not tested the later versions.
>>>
>>> Everything is IT mode where possible.
>> Yes, at least until kernel 4.1 the module was the 4.0 version.
>> And I had no luck at all getting the newer versions into a generic kernel
>> or Debian.
>> And when I deployed the machines in question P8 was the latest FW from
>> Supermicro.
>>
>> Kernel 4.4 does have the 9.x module, so I guess that's a way forward at
>> least on the kernel side of things (which I think is the more likely
>> culprit).
>
> I'm using Supermicro HBAs as well, but getting the drive directly from
> Avago.  On their site, I just look for the firmware for the 9300-8i.
> I've successfully used their utilities to cross-flash a 3008-based HBA
> from IR to IT mode.
>
> The package also includes an SRPM, which I've found to build
> relatively easily.  IIRC, some mods to the spec file were required,
> but that's about it.
>
>
> Cheers,
>
> Heath
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