Since I had some extra 256GB Samsung 830 SSDs on hand, I decided to test them in unRAID.

 

With just one SSD as Disk 1, I could copy to it over the network at 121MB/sec from the RAMdisk on my workstation.

 

So I set up Disk 1 and parity both on SSDs.

 

Initial parity sync was 220MB/sec.

 

A parity check ran a little slower, at about 190MB/sec.

 

Copying to the parity-protected drive over the network was 83MB/sec.

 

CPU load was about 35% for smbd.  This is a dual-core AMD system, and the load was fairly evenly split among the 2 cores.

 

Reading from the parity-protected disk1 was a bit faster... 91MB/sec.

 

Now the odd part.  When reading, CPU maxed out at 100% on ONE core... the other core was near idle.

 

So I tried multiple simultaneous reads, and still, smbd was maxing out 1 core, and the other was near idle.

 

I had read that smbd was single-threaded, and understand that is really necessary for some good reasons.... bit I never thought I'd max out a 3.2gHz CPU.

 

System is a GA-MA790GP-UD4H with AMD Athlon II X2 260 Processor and 8GB or RAM.

 

 

I wonder whether this explains why some people are reporting dropouts when playing media files and initiating other disk activity

Disk IO halts on all disks while a sleeping disk spins up. That's the only thing I've ever had cause a dropout in media reads...

I wonder whether this explains why some people are reporting dropouts when playing media files and initiating other disk activity

There are no media files that are encoded at 90MB/sec. That's 720mbps.

 

See my sig for a multiple Blu-ray streaming test. You should be able to stream at least 4 full Blu-ray discs simultaneously on a LOW END system.