difference between SSD RAID10 and number of SATA3 RAID 10

Answers

The SSD system will be way faster then the hard drive solution - and more reliable (SSD is and order of magnitude more reliable then hard drives) - you will be paying more for storage however.

Its impossible to advise the difference unless the load (and specific disks) are known, but for a typical use case I'd expect the SSD's to be in the order of magnitude of 2-3 times the speed of hard drives if managing fewer larger files, and 10 times+ the speed for lots of small files scattered throughout the disk.

If you are looking at something to act like a NAS, considure a combination of HDD's and SSD's and ZFS to get the best of both worlds.

The "sequential" speed of an SSD is in the order of magnitude of 5 times that of a hard drive (and this figure would, in some cases be reduced because you have 3 times as many disks on the hard drive), however the magic is the 100x order of magnitude difference in scattered reads - because hard drives need to wait for the platter to spin under the head, while there is no mechanical delay accessing an SSD.

davidgo

Posted 2017-05-16T03:54:55.230

Reputation: 49 152

Thank you for your description, Do you know an approximately speed in SSD and SATA3? Do you know which 12 hard drives in RAID will get 12 x read speed ? Check this site: raid-calculator.com – Farhad Sakhaei – 2017-05-16T05:17:12.850

See http://ark.intel.com/products/94209/Intel-SSD-540s-Series-480GB-2_5in-SATA-6Gbs-16nm-TLC for a typical server class SSD - read speeds up to 560MB, write speeds up to 480MB/s. (Its designed for SATA3). With the correct controller any 12 disks in a RAID could give up to a 12x read speed, but it assumes that the data being read is evenly spread across all disks and the controller is smart enough to balance everything ideally - which is almost certainly an incorrect assumption. The same is true of SSD's. Consider getting extra memory the OS cana use as read cache.

– davidgo – 2017-05-16T07:38:38.990

You're going to have a hard time arriving at a hard number depending on what kind of reading / writing you're comparing to, e.g. are reads / writes sequential, random, or both. All else remaining equal, assuming same RAID, JBOD, or whatever configuration, SSD is going to win on speed pretty much no matter what. – BrianC – 2017-05-16T04:00:42.020

Are you sure it is RAID 10 with 4 480GB drives? That only gives you 960GB so if you need more, then that option (probably faster, no way to tell without specs) isn't for you. – Paul – 2017-05-16T04:12:17.270

@BrianC I know using number of drive in RAID we will have more speed read , you can check this site for that : raid-calculator.com, for SATA we will have 12x read and 6x write speed gain, But I it based on 1 SATA drive speed – Farhad Sakhaei – 2017-05-16T04:16:46.977

@Paul , It is not problem with 960GB too , I can add another HDD beside that too, Just need to know which combination have more speed for main drive – Farhad Sakhaei – 2017-05-16T04:17:58.767

@FarhadSakhaei Correct, that calculator is giving you a multiplier relative to the speed of the drive (could be HDDs, SSDs, doesn't matter). My answer still is - SSDs read/write faster, but certain kinds of reads/writes will have more drastic gains than others, so I don't know if it's possible to answer correctly – BrianC – 2017-05-16T05:05:29.857