Very slow SAS HDD performance for Supermicro X9DR3-LN4F+-B under ESXi 5.5. Any idea?

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nk215

Active Member
Oct 6, 2015
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Hi guys,

I tried out the built in SAS ports in my Supermicro X9DR3-LN4F+-B over the weekend and the performance has been very bad.

Connecting to a 4TB Seagate SAS drive. I added this disk as a datastore. Create a VM HDD using this disk for a Win10 guest VM.

Copying speed to this HDD is ridiculously slow at around 5mbytes/s. SATA HDD under the same configuration gets me 80mbytes/sec.

I am pretty sure the HDD is not an issue (it works fast if connecting to a M1015 SAS ports). What's going on with Supermicro X9DR3-LN4F+-B built-in SAS port under ESXi 5.5? The motherboard is new in box. I just plugged it in and didn't do anything special as far as built in controller configuration.

If I am missing drivers or anything, please let me know.

Thanks
 

nk215

Active Member
Oct 6, 2015
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49
Still working on this.

The copy job starts out fine at full speed. After 5 hours, it slows down significantly for no real reason until the job is completed (total 9 hrs to copy 1.4TB). Controller is not overheated.

Will do more testing in the next few days