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Slow Sequential Read on RAID 1 ??? Why?

Joined
Oct 10, 2005
Messages
127 (0.02/day)
I have a Intel 2500K Process and a 3TB RAID 1 on a 2 x SATA 3Gb/s Port on a Intel® Rapid Storage Technology RAID ARRAY. Im using the 3TB RAID 1 ARRAY for storage and im using a Crucial M4 128GB drive for my primary boot drive. My M4 drive operates normal good speeds. However on my RAID 1 ARRAY Ive noticed my Sequential Read speeds are slow (compared to what they should be), or at least they seem slow to me because im not sure if it is normal but my Sequential Read is around 75MB/s and the Sequential Write is around 140 MB/s which seems normal for the write but not for the READ. BEFORE i did any RAID the SEQ READ/WRITE were both around 120-140 for both drives. why is it that my READ speed is so slow after i did a RAID 1?? I've attached my CrystalDiskMark log below. My 3TB RAID 1 array are using a Seagate ST3000DM001 and a Seagate ST33000651AS



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CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
Crystal Dew World : http://crystalmark.info/
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* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

Sequential Read : 73.481 MB/s
Sequential Write : 140.259 MB/s
Random Read 512KB : 49.253 MB/s
Random Write 512KB : 89.153 MB/s
Random Read 4KB (QD=1) : 0.728 MB/s [ 177.7 IOPS]
Random Write 4KB (QD=1) : 1.233 MB/s [ 300.9 IOPS]
Random Read 4KB (QD=32) : 3.247 MB/s [ 792.7 IOPS]
Random Write 4KB (QD=32) : 1.271 MB/s [ 310.3 IOPS]

Test : 500 MB [E: 33.6% (938.8/2794.4 GB)] (x2)
Date : 2012/02/22 8:51:38
OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
 
Looks fine to me, most 3TB drives are "green" and as the requests drop they park their heads more often. Plus you get no speed boost over a single drive from RAID1.
 
Looks fine to me, most 3TB drives are "green" and as the requests drop they park their heads more often. Plus you get no speed boost over a single drive from RAID1.

never mind i ran HD tune and HD Tach and the drives were fine, i guess its the way that Crystal mark was doing the bench. Using other benchmarking software the Sec Read was about right around 120-30 average. BTW it was not green drive it was a 7200 RPM drive.
 
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