Two SSDs and different performance

JohnD212

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Aug 22, 2011
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Hi, I recently installed a second Samsung 840 Pro in my computer. My system had two Serial ATA 6.0Gb/s connectors. The first has my original 840 Pro and the second now has my other one. When I run the benchmark tests that comes with Samsung software it is showing significantly lower performance for the second (newer) drive. Everything is optimized exactly the same as my original drive so I'm not sure why I"m getting different results.

Any ideas?
 
No. I have not enabled rapid mode on either. I have the Asus P8 Z77-V Deluxe Mother board and it has 4 6Gb/sec SATA ports. Two are regular ones and two can be used to as either a regular SATA ports or a super cache thing. I haven't enable the cache thing. I have my SSD that contains my OS in a reglular 6GB/sec SATA port, then my older 840 Pro in the other plug. In the super cache ports (that are also 6Gb/sec ports) I have my new 840 Pro SSD and my Western Digital HDD. I don't see anything that would cause such lower performance. Here is what I get:

Older 840 Pro : Seq Read=559 Seq Write=536 Random Read = 99112 Random Write= 90079
New 840 Pro : Seq Read=389 Seq Write=175 Random Read = 49155 Random Write=30543

 
I actually did some more research and realized there are only two Intel SATA ports and the other two are Marvell. From my understanding the Marvell just doesn't perform as well as the Intel. I turned on the Rapid mode and that has made the drive much better. Thanks.