Hi ToddAndMargo!

 On 2015.05.06 at 00:48:30 -0700, ToddAndMargo wrote next:

> http://www.intel.ie/content/dam/www/public/us/en/documents/white-papers/ssd-dc-s3500-workload-raid-paper.pdf
>
>
>      The system used for RAID 1 testing include the following:
>      • LSI MegaRAID 9265-8i* controller card
>
>      To summarize:
>      • In both RAID 1 and RAID 5, the Intel SSD DC S3500 Series
>        drive shows excellent scalability, performance, and consistency.
>
>      • Very little latency was introduced by the RAID controller
>        in RAID 1. In RAID 5, the overhead and latency are slightly
>         higher.
>
>      • In random, mixed read/write workloads, SSDs perform
>        significantly (as much as 100 times) better than HDDs
>        in a similar situation
>
>
> Maybe the S3500 is what I want?  They are still available
> at my distributors.

They are fine drives. In fact, I got servers running them; excellent
performance, no problem with incompressible data (unlike drives with SF
controllers) - this matters to me because I'm using zfs on linux with
compression. Sustained write speed >500 MB/s (480GB model).

However, like I said before, if long-term performance is needed, I
advise against using them in hardware RAID controller. This document
only shows after-install performance; they didn't do any endurance
testing. Without TRIM, performance of this drive will degrade.
Buy Plextor M5/M6 if your environment doesn't support TRIM.


I'm curious, what stops you from using software RAID with mdadm?
For two-disk RAID 1 it provides excellent performance, high
compatibility and TRIM support. I could understand if you needed
hardware controller for RAID6 with tons of disks, in RAID6 or something,
but for two-disk RAID1?..

--
 
Vladimir