Slow transfer rate after ram increase

[bobrules81]

Hi,
I'm a newbie so please forgive me if it seems simple. I built my nas initially with 2 gb ram and have since increased to 8 gb. With 2 gb ram I could transfer a solid 90-100MBS across gigabit network. Since ram upgrade it ranges from 2-40MBS. I have tried re installing freenas several times & I've tried different versions of freenas (8.3.2 and 9.1.1) with no improvement. Can somebody help?
I'm back to running 8.3.2 as I've had more success setting up plugins on this version.
System is Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz, 8175MB RAM, 4x4tb hdd raid Z2.

 

[bobrules81]

Sorry for cross posting. Was unsure if it posted here or not as net died right after I edited it. I just removed 4gb ram and now the transfer rate is back to the solid 90-100MBS. Any help would be grat.

 

[warri]

Have you tested the RAM (for example with memtest)?