Synology RAM upgrade. Useful or not?

[asheenlevrai]

Hi everyone

I am currently using a Synology DS1819+ as a file server and to host a wiki (~20 users).

The device comes equipped with 4GB of DDR4 and so far RAM usage has remained below 20% (usually around 15%). I guess this means that 1GB of RAM would be enough for what my DS does, right?

I now have the opportunity to replace those 1x4GB by 2x8GB. Or I could use these 2x8GB elsewhere... It doesn't seem to make any sense to add more RAM into my DS1819+ but I was told that DSM would actually use free RAM as cache to improve performance. This could be useful indeed but I'm not sure it's actually true. And even if it is true, I guess this cache is used only for writes (not reads), right?

What would your recommend I do with these 2x8GB of DDR4? Use it in the Synology? Use them elsewhere?

Thank you very much in advance for your advice.

Best,
-a-

 

[fredbert]

Hi. Some of the packages can be set to use unused RAM to cache. E.g. Synology Drive Admin Console has a setting for this. Have a look through your packages and see what has this feature.

Look in Resource Manager -> Memory and you'll see how 'Used' (active) isn't the only assignment. Here's my 8GB RAM and swap usage. My usage rarely swaps to disk, which is slower to swap back than if it is kept in RAM.

 

[Rusty]

I would advise getting more RAM. Lots of breathing room with more RAM.

 

[asheenlevrai]

I would advise getting more RAM. Lots of breathing room with more RAM.

Thanks
Can you elaborate a little bit please

-- post merged: 11. May 2021 --

Hi. Some of the packages can be set to use unused RAM to cache. E.g. Synology Drive Admin Console has a setting for this. Have a look through your packages and see what has this feature.

Thanks but I don't understand how I should do that.
Can you please provide some guidance?
Thanks
-a-

 

[Rusty]

Can you elaborate a little bit please

Well exactly what @fredbert said. Better to have RAM as you swap than to use the HDDs. From a performance standpoint, you will get speed and snappy(er) response than with a limiting amount of RAM. Also, it opens up for some other apps/services to run, making more use of the device itself.

 

[fredbert]

Some of the packages can be set to use unused RAM to cache. E.g. Synology Drive Admin Console has a setting for this. Have a look through your packages and see what has this feature.

Thanks but I don't understand how I should do that.
Can you please provide some guidance?

I'd look at VMM, Control Panel, Synology Drive Admin Console, and Snapshot Replication for starters. If you use those packages. The built-in Help should be able to guide you.

 

[Coop777]

Performance Monitor is your friend...I'd say if you are constantly above 50% memory utilization it would be a good idea. I do run 8 GB in both of mine.

 

[Robbie]

I'd at least make sure both DIMM slots are used with similar memory sticks for dual-channel memory mode. The NAS CPU is not exactly a beast so dual-channel memory makes a significant difference in CPU usage and overall performance.

 

[asheenlevrai]

Performance Monitor is your friend...I'd say if you are constantly above 50% memory utilization it would be a good idea. I do run 8 GB in both of mine.

Thanks.
As I mentioned in the OP, I am never above 20% (mostly around 15%).
And my swap usage is 0% (obviously)...
As @Robbie stated, I'd either stay at stock (1x4GB) or go to 2x8GB since it feels awkward to go to 1x8GB or 4GB+8GB.

On the other hand, given my current usage, I wonder if it would be totally overkill to use 16GB of RAM. I could use more "snappyness" for the wiki (dokuwiki) for instance. I guess I should figure out how to run some tests...

 

[Robbie]

Tend to be quite a few 4GB sticks on the used market for not much money for a single stick - not exactly a size in much demand. You may even have a machine somewhere ready to donate such a stick.

That would give you (4+4) 8GB - a handy amount and the benefits of dual-channel memory mode.

 

[Coop777]

I don't run a lot of applications on mine - the only think I've seen spike resources is DS Video.

 

[asheenlevrai]

Tend to be quite a few 4GB sticks on the used market for not much money for a single stick - not exactly a size in much demand. You may even have a machine somewhere ready to donate such a stick.

That would give you (4+4) 8GB - a handy amount and the benefits of dual-channel memory mode.

Apparently I need to double check my information. For some reason I wrote down that the RAM in the DS1819+ was DDR4 2400 but apparently it's DDR4 2133. The only 4GB modules I have are DDR4 2666. I wonder if the DS1819+ would accept anything else than DDR4 2133 (I guess it does since many RAM upgrade tutorials recommend 2400MHz modules).

-> back to the desk

 

[Telos]

2133/2400/2666

 

[asheenlevrai]

2133/2400/2666

Thank YOU so much !

I gave a quick look at the RAM specs for the DS1812+ using the link you provided and they only mention DDR3 1600 when I know for sure it was using DDR3 1066. I never tested if it actually supported DDR3 1600, though.

 

[Tedster]

Strangely, I've just decreased the amount of RAM in my 1515+.

I did have 8GB of 1600 MHz in there but looking at "Resource Monitor" it only ever utilised 7%. Seeing as I could do with those ram sticks for another project. I swapped them out. I put the original 2GB Synology one back in and another 2GB one that I had lying around.

That one was only a 1333MHz chip. It didn't complain and booted right up, showing 4GB. Ram usage now sits at 13%, so about what I'd expect.

It has an easy life, only file serving.

 

[Tedster]

So after, nearly, a couple of weeks. RAM usage sits at 8%. Hard to understand really? So before, with 8GB, it utilised 7% of it. Now with 4GB it utilises 8%. So the more you put in the more it caches, or something.

 

[technorabilia]

So after, nearly, a couple of weeks. RAM usage sits at 8%. Hard to understand really? So before, with 8GB, it utilised 7% of it. Now with 4GB it utilises 8%. So the more you put in the more it caches, or something.

Whenever possbile, Linux will use all available RAM for cache.

root@DS716:~# free -g
              total        used        free      shared  buff/cache   available
Mem:              7           0           0           4           6           2
Swap:             1           0           1
root@DS716:~#