Dropping Throughput with CIFS and AFP Shares

[phaus]

I have some strange behaviour transfering bigger files (>1Gb) onto a CIFS or AFP Share.
The Transfer always starts at around 100Mb/s and then drops to some 2-5Kb/s after some time.
Like as s Buffer runs full and then needs to be written to Disks.

I am using the latest stable Version of FreeNAS: FreeNAS-9.3-STABLE-201506292130

My System is a HP Microserver Gen8

Intel(R) Pentium(R) CPU G2020T @ 2.50GHz
16 GB ECC RAM

My Disks are 4 x WD Green 4TB configured as RAIDZ1 + Hot-Spare.

So ~8TB Disk Space

I already upgraded the RAM to 16GB (from 8GB previously)
I also changed the WD Green Configuration with wdidle to disable the Slow-Down after some Seconds.
I tested with Autotune enabled/disabled - no success.
I am alomst at the end with my ideas.

The last thing is to install a new, fresh version of FreeNAS and test the Transfer again.
Has anyone had the same Issue and found a solution?

 

[SweetAndLow]

What is your source computer and what hardware?

 

[phaus]

My Source Computers are

a 2014 Macbook Pro for the AFP Transfer (Thunderbolt to Gigabit Ethernet Adapter)
a Asus Workstation for the CIFS Transfer (Intel NICs)

 

[anodos]

I have some strange behaviour transfering bigger files (>1Gb) onto a CIFS or AFP Share.
The Transfer always starts at around 100Mb/s and then drops to some 2-5Kb/s after some time.
Like as s Buffer runs full and then needs to be written to Disks.

I am using the latest stable Version of FreeNAS: FreeNAS-9.3-STABLE-201506292130

My System is a HP Microserver Gen8

Intel(R) Pentium(R) CPU G2020T @ 2.50GHz
16 GB ECC RAM

My Disks are 4 x WD Green 4TB configured as RAIDZ1 + Hot-Spare.

So ~8TB Disk Space

I already upgraded the RAM to 16GB (from 8GB previously)
I also changed the WD Green Configuration with wdidle to disable the Slow-Down after some Seconds.
I tested with Autotune enabled/disabled - no success.
I am alomst at the end with my ideas.

The last thing is to install a new, fresh version of FreeNAS and test the Transfer again.
Has anyone had the same Issue and found a solution?

Why do a 3-disk RAIDZ1 + hot spare instead of 4-disk RAIDZ2? It seems like a poor trade-off.
Have you tried directly connecting FreeNAS -> Client? Have you reviewed /var/log/messages?