[gales]

  I originally put a system together using ASRock X99 Extreme 11 motherboard, Adaptec 81605z controller and 10 Micron 1TB drives using RAID 0. My first test ran and filled the 10TB in about 42 minutes. I tested the integrity if the data and found no discontinuities. I tested with IOMeter and found ~6.5GB/s using 16kB sequential writes with 4 worker threads. I thought life was good and this was easy to get working.

  I then put the same drives and adaptec card into a Intel server with S2600CWTR  server board and configured the Adaptec controller the same as my desktop above. Now I can't get the performance I was seeing above. I reconfigured the Adaptec controller to optimize for database access, tried it again. Still bad performance. I reconfigured back to my original setting "optimize dynamically" and my performance popped up (~6GB/s). Problem is it won't sustain. After awhile I start dropping data, meaning it can't maintain the 4GB/s data rate that I require. I just recently went back to the ASRock system and now after 5~10 seconds the data rate starts dropping according to my original tests with IOMeter that maintained that rate for the entire fulling of the array. I'm now sanitizing the drives and will try it again.

 

My question is: does anyone know how to configure such a system using the Intel server board that can maintain that data rate reliably? I have two configurations 10) 1TB drives and 16) 2TB drives. Currently neither one works.

 

Thank you in advance,

Gale

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This should help some: https://superuser.co...ite-performance

 

More here: https://www.google.c...mance on RAID 0

[SpywareDr]

This should help some: https://superuser.co...ite-performance

 

More here: https://www.google.c...mance on RAID 0

[terry1966]

simple fact is in my opinion you don't have enough drives in raid 0 to sustain 4GBs writes.

 

say a drive has 100MBs av write speed, (speed changes depending on where on the drive data is being written) so for 4GBs you would need 40 drives in raid 0.

40x100=4000 or 4GB

 

so i'd expect your 10 drives in raid 0 to be able to sustain about 1GBs (8Gbs) write is that what your seeing?

 

when you initially start writing to a drive it will fill up it's cache first (which is much faster than writing directly to the drive platters.) and why it starts off very fast, but as soon as the cache is filled it then needs to write the data from the cache to the drive and this is when things slow down to it's actual write capabilities.

 

anyway to get 4GBs sustained you will need to know what the write speeds of your drives are and then have enough of them in a raid 0 setup to accomplish what you require.

 

eg. max sustained data rate for a 4TB wd red is 150MBs according to this review, notice that's max and not minimum :- http://techreport.co...-drive-reviewed

 

so even using it's max writes you'd need 27 drives in raid 0 to get your required 4GBs

4000/150=26.666

 

must admit that is a lot of data you want to write per second and i can't think of anything a normal home user would need such high transfer speeds for, not even recording 4k video at 60fps needs 4GBs write speeds as far as i know.

 

Edited by terry1966, 22 July 2016 - 10:22 AM.