SSD testing and results

Question

linux

Good afternoon. Ran into strange results when testing dedicated servers.
Servers:
1) MSI H87-G43 motherboard (6 channels SATA 6GB/s). 4 drives in softraid 10: 2 Samsung SM843T drives and 2 Intel SSD 520 series 240 Gb drives.
2) MSI H87-G43 motherboard (6 SATA 6GB/s channels), but it costs 2 Intel SSD 520 series 240 Gb disks in soft raid1.
3) Mother - SuperMicro X9SCMF + dedicated controller LSI_MegaRAID_SAS_92404i. 4 hard raid 10 disks: 2 pcs. PNY_Prevail_Elite and 2pcs. PNY_Prevail_5K for 240 Gb.
4) Mother - SuperMicro X9SRI3F. 4 soft raid 10 disks: 4 pcs. Kingston_SSDNow_KC300 480 GB.
dd utility results on centos:
Writing (dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync oflag=direct)
1) 366
2) 350
3) 225
4) 237
Read (dd if=test of=/dev/null bs=1M count=1024 iflag=direct)
1) 886
2) 392
3) 721
4) 523 The
question is why 3rd server reading 1.5-2 times less than on the first two configs? Who is to blame (motherboard/controller/drives)? Maybe I'm testing/compiling something incorrectly?

Answer 1

IMHO. Perhaps because PNY itself is slower than Intel will be ....