7200 Rpm and 5400 Rpm Question

[Soulflyzz]

Hello, Band new to Unraid Less then 24 Hours.

 

I am setting up my system and i have 2x  Samsung_SSD_860_EVO_500GB_S3Z1NB0KA74690K for my Cashe Drives

I also Have 4x 6Tb 7200rpm Drives set up 1x Parity and 3 x Drives.

 

But i am also sitting on 4x 4TB 5400 Green Drives from an old system currently not in use.

 

Now my question should i stick with just my 4x 6Tb 7200rpm system or add the other 4x 4Tb 5400 rpm drives.

I am asking for performance sake not storage sake. Will those drive bottleneck my system in any way?

 

Thank you,

Edited December 10, 2019 by Soulflyzz

[trurl]

Since each disk is independent in Unraid, the speed of those disks would only matter if you were reading or writing them, or possibly if you were using "Turbo Write" where all disks are read in order to update parity. I would say don't worry about it.

 

But, I always recommend not installing more disks than you need for capacity. Each additional disk requires an additional port, additional power, at some point more Unraid license, and most importantly, each additional disk is an additional point of failure. Don't install old disks just because you have them.

[Soulflyzz]

Thank you for the update,

So the direct answer to the question is no it should not affect performance.

The long answer is don't add them unless needed.

[Frank1940]

28 minutes ago, Soulflyzz said:

So the direct answer to the question is no it should not affect performance.

This should really be qualified.  7200RPM disks are faster than 5400RPM  IF  all other factors are equal-- things like capacity/size. data density, etc.   Usually you tend to see the effect when you do extended disk operations like parity checks.   I would not replace 5400RPM drives with 7200RPM thinking it would make a world-shaking improvement in performance. It won't...

[Soulflyzz]

Darn Now i have 2 conflecting answers (Just like me google searches).

I know that 7200 rpm and 5400 are different and will have different results one to one.

My question was directed to my exact situation. I am not looking to replace any drives, I have 4x 7200rpm drives installed and would like to add 4x more 5400rpm drive that i already have. If i add them will i have a notable loss in performance?

 

thank you again i hope this helps?

[JorgeB]

2 minutes ago, Soulflyzz said:

If i add them will i have a notable loss in performance?

Parity check/sync will be slower, writes with normal writing mode will likely be a little slower, if using turbo write difference will be bigger, but also depends on the rest of the hardware and what model are the 6TB disks, mainly how many platters they have.

[Frank1940]

And disk capacity, smaller size disks have lower bit density so fewer bits pass under the heads for each rotation of the disk.  As I said, all of these are factors in how fast a disk can be read or written.  One could find that a 5400RPM large-size disk could have much better performance than a 7200RPM small-size disk.  Particularly, when comparing 1-3TB disks to 10-12Tb disks!  

 

I notice the difference in read speeds in my monthly parity check when the smaller capacity disks are finished on both of my servers.  For comparison, it takes my testbed server (with a mix of 1 & 3 TB drives0 about 8 hours to finish and the Media server (with a mix of 3T & 6TB drives about 12 hours to finish.