Comparing with these SSDs, S3710s S3610s SM863 845DC Pro which one is more reasonable in terms of performance, cost or whatever? S3710s does not sound reasonable to me. > And I had no luck at all getting the newer versions into a generic kernel > or Debian. So it's not always better to use newer version. Is my understanding right? If I don't understand that properly, point it out to me. I'm pretty serious about that. Cheers, Shinobu On Fri, Mar 4, 2016 at 3:17 PM, Christian Balzer <chibi@xxxxxxx> wrote: > > Hello, > > On Mon, 29 Feb 2016 15:00:08 -0800 Heath Albritton wrote: > >> > Did you just do these tests or did you also do the "suitable for Ceph" >> > song and dance, as in sync write speed? >> >> These were done with libaio, so async. I can do a sync test if that >> helps. My goal for testing wasn't specifically suitability with ceph, >> but overall suitability in my environment, much of which uses async >> IO. >> > 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. > >> >> >> SM863 Pro (default over-provisioning) ~7k IOPS per thread (4 threads, >> >> QD32) Intel S3710 ~10k IOPS per thread >> >> 845DC Pro ~12k IOPS per thread >> >> SM863 (28% over-provisioning) ~18k IOPS per thread >> >> >> > Very interesting. >> > To qualify your values up there, could you provide us with the exact >> > models, well size of the SSD will do. >> >> SM863 was 960GB, I've many of these and the 1.92TB models deployed >> 845DC Pro, 800GB >> S3710, 800GB >> > Thanks, pretty much an oranges with oranges comparison then. ^o^ > >> > Also did you test with a S3700 (I find the 3710s to be a slight >> > regression in some ways)? >> > And for kicks, did you try over-provisioning with an Intel SSD to see >> > the effects there? >> >> These tests were performed mid-2015. I requested an S3700, but at >> that point, I could only get the S3710. I didn't test the Intel with >> increased over-provisioning. I suspect it wouldn't have performed >> much better as it was already over-provisioned by 28% or thereabouts. >> > 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. > >> It's easy to guess at these sort of things. The total capacity of >> flash is in some power of two and the advertised capacity is some >> power of ten. Manufacturer's use the difference to buy themselves >> some space for garbage collection. So, a terabyte worth of flash is >> 1099511627776 bytes. 800GB is 8e+11 bytes with the difference of >> about 299GB, which is the space they've set aside for GC. >> > Ayup, that I was quite aware of. > >> Again, if there's some tests you'd like to see done, let me know. >> It's relatively easy for me to get samples and the tests are a benefit >> to me as much as any other. >> > Well, see above, diminishing returns and all. > >> >> >> I'm seeing the S3710s at ~$1.20/GB and the SM863 around $.63/GB. As >> >> such, I'm buying quite a lot of the latter. >> > >> > I assume those numbers are before over-provisioning the SM863, still >> > quite a difference indeed. >> >> Yes, that's correct. Here's some current pricing: Newegg has the >> SM863 960GB at $565 or ~$.59/GB raw. With 28% OP, that yields around >> 800GB and around $.71/GB >> > 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've not had them deployed >> >> for very long, so I can't attest to anything beyond my synthetic >> >> benchmarks. I'm using the LSI 3008 based HBA as well and I've had to >> >> use updated firmware and kernel module for it. I haven't checked the >> >> kernel that comes with EL7.2, but 7.1 still had problems with the >> >> included driver. >> >> >> > Now THIS is really interesting. >> > As you may know several people on this ML including me have issues with >> > LSI 3008s and SSDs, including Samsung ones. >> > >> > Can you provide all the details here, as in: >> > IT or IR mode (IT I presume) >> > Firmware version >> > Kernel driver version >> >> When initially deployed about a year ago, I had problems with SSDs and >> spinning disks. Not sure about any problems specific to Samsung SSDs, >> but I've been on the upgrade train. >> >> 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). > > Thanks, > > Christian > -- > Christian Balzer Network/Systems Engineer > chibi@xxxxxxx Global OnLine Japan/Rakuten Communications > http://www.gol.com/ > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Email: shinobu@xxxxxxxxx GitHub: shinobu-x Blog: Life with Distributed Computational System based on OpenSource _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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