Re: SSD-RAID for new wide-field microscopy system

Posted by Michael Giacomelli-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/SSD-RAID-for-new-wide-field-microscopy-system-tp7589536p7589546.html

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Hi Zdenek,

SATA SSDs have been obsolete for a while now.  PCIe 3.0 NVME devices
have a bidirectional 4GB/s transfer rate.  For smaller acquisitions,
any cheap device will be protocol limited (> 3GB/s), but only for the
first 50-100GB, and they'll drop down to about 1GB/s as the disk fills
up.  More expensive devices can sustain closer to 2GB/s over the
entire space.  Very expensive devices will sustain 3GB/s, but there is
no point with RAID.  Just buy another disk and you get more capacity
and the same bandwidth for less.

By the way, now that SSD storage is hitting $100/TB, and PCIe 4.0
devices are about to launch, affordable devices with 6-7 GB/s
bandwidth in a single drive shouldn't be too far away.  I think pretty
soon there will be little point in RAID; parallelism will be internal
to the "disk".

Mike

On Thu, May 23, 2019 at 10:52 AM Zdenek Svindrych <[hidden email]> wrote:

>
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> *****
>
> Hi Mike,
> where did you get the numbers? Regular SSDs I've seen are around 500 MB/s,
> both read and write. And SATA III speed is around 600 MB/s!
> That's not quite enough even for a single 10-tap CameraLink camera (800
> MB/s).
> SSD RAID may seem an overkill, but you don't want to sacrifice speed just
> because of poor PS specs... Of course RAID 0 array of regular hard drives
> should work too, but the probability of data loss (due to failure of one of
> the disks) rises with number of disks.
> Best, zdenek
>
> On Thu, May 23, 2019 at 10:14 AM Michael Giacomelli <
> [hidden email]> wrote:
>
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.umn.edu_cgi-2Dbin_wa-3FA0-3Dconfocalmicroscopy&d=DwIFaQ&c=kbmfwr1Yojg42sGEpaQh5ofMHBeTl9EI2eaqQZhHbOU&r=0LyF_z8oU1XGGyisIeOIXyIGIM5IYb3NcLjxHjUca5Y&m=QQs8Y17ATbc0ymJwJplCIBmeOhYv7aHFM68KU966354&s=7y0U_-tpAhO9gQanIo1BngyWx9ur1ny6Ctwdzd0rQv8&e=
> > Post images on https://urldefense.proofpoint.com/v2/url?u=http-3A__www.imgur.com&d=DwIFaQ&c=kbmfwr1Yojg42sGEpaQh5ofMHBeTl9EI2eaqQZhHbOU&r=0LyF_z8oU1XGGyisIeOIXyIGIM5IYb3NcLjxHjUca5Y&m=QQs8Y17ATbc0ymJwJplCIBmeOhYv7aHFM68KU966354&s=__SRaWSmRiycUG3SBFXuuAhfxcv3RJUdfkrkUwovNAM&e= and include the link in your posting.
> > *****
> >
> > How fast are you acquiring data?
> >
> > Entry level SSDs are about $120/TB (~1GB/s write) while high
> > performance SSDs are $250/TB (~2.5 GB/s write).  Since SSDs are very
> > inexpensive, that $6000 is probably getting you more than just a
> > couple hundred dollars worth of disks?
> >
> > Mike
> >
> > On Thu, May 23, 2019 at 9:49 AM Mirco Martino <[hidden email]> wrote:
> > >
> > > *****
> > > To join, leave or search the confocal microscopy listserv, go to:
> > >
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> > > Post images on
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> > and include the link in your posting.
> > > *****
> > >
> > > Hi all,
> > >
> > > we are buying a new fluorescent microscope wide-field system. The system
> > include a workstation with 64GB DDR4 RAM, 11GB of graphic card, 512 gb of
> > memory and SSD-RAID of 2TB. There is an option to increase the SSD-RAID to
> > 4TB for  about 6000$ extra. The system will be use for both fixed materiel
> > imaging and for live-imaging with time-laps, z-stack, tiling and
> > multi-fluorophores experiments. I was wondering if it is worth to invest
> > those extra money for this option or not. This will be the first time we
> > will have time-laps experiments, so I don't know what to expect as pictures
> > size.
> > >
> > > What do you think?
> > >
> > > Thanks in advance for your comments and opinions!
> >
>
>
> --
> --
> Zdenek Svindrych, Ph.D.
> Research Associate - Imaging Specialist
> Department of Biochemistry and Cell Biology
> Geisel School of Medicine at Dartmouth