mem upgrade speed gain?

[Steve M Cline]

Dear Community

I am new to this forum and pretty new to freenas too.
I run a freenas server with 8GB Ram and two 3TB hardrives as a ZFS mirror.
I could upgrade to 16 GB or 20 GB of Ram for a relatively cheap price,
but I would only like to do it if I could see a noticable performance gain.

What do you think, is it worth the expenditure?

Thank you for your opinions

 

[enemy85]

I don't think you will gain that much because u have just 2x3TB ...but wait for other replies to be sure!

 

[Yatti420]

The best way to get better performance is give FreeNAS more ram..

 

[gpsguy]

We don't know much about the OP's hardware. Perhaps a NIC upgrade is needed or a CPU upgrade.

Look at the forum rules and give us more information.


Sent from my phone

 

[Steve M Cline]

I am sorry, you are right, I should have been more specific.

It is an old Supermicro server X6DHR-iG2:

CPU: 2x Xeon Irwindale 3,4 GHz
Chipset: Intel E7520 Lindenhurst
NIC: Intel 82546GB Gigabit Ethernet
RAM: 8 GB DDR2-400 ECC
SATA Controller: Intel ICH5R onboard configured non-Raid

 

[krikboh]

Two single core "Pentium IV's" with 2 MB of cache each are probably your bottleneck, not the RAM.

 

[eraser]

The more RAM you have installed, the more memory ZFS will be able to use as a read cache.

You could run the "arc_summary.py" script from a shell and review the "Most Recently Used Ghost:" and "Most Frequently Used Ghost:" values. If the Ghost values are high, then adding additional RAM should help.

This blog post will explain what the "Ghost" entries are: http://www.cuddletech.com/blog/pivot/entry.php?id=979

 

[enemy85]

The more RAM you have installed, the more memory ZFS will be able to use as a read cache.

You could run the "arc_summary.py" script from a shell and review the "Most Recently Used Ghost:" and "Most Frequently Used Ghost:" values. If the Ghost values are high, then adding additional RAM should help.

This blog post will explain what the "Ghost" entries are: http://www.cuddletech.com/blog/pivot/entry.php?id=979

excellent read...thanks for the link!