coalfield

Synology SHR Vs RAID5 which is faster (Gen 8 Microserver)

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I have been struggling to find this info out so tested it myself.

 

On a HP Microserver with 4x WD RED 3TB using SHR Dual Redundancy writing large files produces 70 MB/s utilising the Gigabit connection approx 70%.

For smaller files (i.e. photos), the throughput was around 50MB/s and 50% utilisation (writing).

Reading was ~75MB/s not affected significantly by the file type.

Increasing the number of copy streams shares this total bandwidth, so total throughput does not increase.

 

With the same setup on RAID 5 (note: single disk redundancy only) on large files I get approx 100 MB/S which is essentially a 100% utilisation of gigabit.

For smaller files I get 50MB/s, similar to SHR.

However increasing the streams, i.e. a copy of large files with small files separately but simultaneously produces a transfer speed of 90MB/s, almost a complete utilisation of Gigabit.

Reading was ~100MB/s not affected significantly by the file type.

 

If an aggregated dual LAN was setup , I am sure the speed would be faster on RAID5 as it appears to be network limited.

 

I hope this helps some. For me the clear choice unless you have mixed drives is to go for RAID over SHR, at least if you dont intend to expand in the future. Some forums state there is only a slight overhead for SHR (as quotes by synology), however in my experience this is not the case, the overhead is significant.

 

Will update once I have aggregated the LAN :grin:

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SHR dual drive redundancy is essentially RAID6 its always slower because of extra overhead.

SHR single drive redundancy is RAID5.

For 4-5 drives normally RAID5(SHR1) is a preferred setup unless extra redundancy is really required and you're ready to pay for it with lost space and performance penalty of RAID6.

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Fair point I didn't try SHR with single redundancy but still cant see any advantage over RAID if the drives are all the same an no future expansion requirement

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coalfield thank you for sharing your findings.

 

But to make a fair comparison you need to compare Raid5 with SHR-1 (1disk redundancy) and/or Raid6 with SHR-2 (2disk redundancy)...

 

If you got the time to test SHR-1 and/or Raid6, you will be able to make a comparison of SHR vs RAID.. If you do please report back your findings =)...

To be honest I am expecting SHR-1 and Raid5 to be nearly identical..

 

MaZeeT

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To be honest I am expecting SHR-1 and Raid5 to be nearly identical..MaZeeT

 

They are since overhead of LVM on SHR is very minimum and bottleneck is networking.

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