Available space for a RAID 5 lower than expected

[PerKalkyl]

Hi!

I am doing some tests by setting up a RAID 5 on a Z590 equipped (Gigabyte Z590I AUROS Ultra) motherboard, and are a little confused as to the amount of available space.

My setup consists of 4 X Samsung 870 QVO 8TB SSD disks.

The setup was a breeze, but after the RAID 5 was initialized, that total amount of available space is slightly less than 22TB. Why is it 2TB less than the expected 24TB?

I am used to setting up Synology's NAS where it delivers 75% of total disk space in a RAID 5.

I would very much like to hear any input on this.

Best regards

Per

[JosueO_Intel]

Hello PerKalkyl,

Thank you for posting on the Intel communities. In order to have a better understanding of the issue, please share with us the following information: 

1. RST version.
2. BIOS version.
3. Screenshot of the issue and RST BIOS configuration. 

Regards, 

Josue O.  

Intel Customer Support Technician

[PerKalkyl]

Dear Josue

I have done dome reading this morning, and maybe it has to do with the fact that this is a raid based on SSD disks? I have attached screenshots for your info. But if I am to understand it correctly, the manufacturers (Samsung in this case) of SSD discs set aside app. 7% of space for bad cells etc. Is this the reason for the difference in actual space?

BR
Per

[JosueO_Intel]

Hello PerKalkyl

Thank you for the information provided.  

I will proceed to check the issue internally and post back soon with more details. 

Regards, 

Josue O.  

Intel Customer Support Technician

[JosueO_Intel]

Hello PerKalkyl

In this case, we can confirm that this is expected behavior when creating the array. 

If you want to check the features of your SSDs and extra information on how they work, our recommendation is to check with the manufacturer for the full specifications. 

Hope this information is useful, if you need any additional information, please submit a new question as this thread will no longer be monitored. 

Regards, 

Josue O.  

Intel Customer Support Technician