1.5TB Seagate 7200.11 RAID-1 Perc 5/i Quirkiness

[Stereodude]

So, I created a 2 x 1.5TB Seagate 7200.11 RAID-1 array on the Dell Perc 5/i in my desktop. I benchmarked it with my IOmeter ATTO imitation clone pattern and got the following odd results.

2 x 1.5TB Seagate 7200.11 RAID-1:

I was expecting something more like this.

2 x 750GB Samsung 7200RPM RAID-1:

The results were so odd, I convinced myself they were wrong and ran it over again.

2 x 1.5TB Seagate 7200.11 RAID-1 Take 2:

Same thing. I decided to benchmark the drives separately to see if the RAID-1 results were perhaps some sort of odd interaction between the two drives.

1.5TB Seagate 7200.11 #1:

I then ran the second drive to see if it was the same.

1.5TB Seagate 7200.11 #2:

They're basically the same as the RAID-1 results. :dunno:

I am currently working on running the same test using the ICH9R.

 

[Stereodude]

1.5TB Seagate 7200.11 (ICH9R):


The drive is much faster on the Perc 5/i (nearly 4x) with small blocks read / writes than the ICH9R. But, the ICH9R doesn't have the fluctuating results at higher block sizes. It seems the Perc 5/i is grouping reads and writes for a speed boost. Not sure why it works perfectly with the Samsung drives, but not the Seagate drives.

 

[Mercutio]

Differing firmware optimizations?

 

[Stereodude]

Not sure...

Clearly whatever the Perc 5/i does to accelerate small block Read / Write doesn't fully agree with the 1.5TB Seagate 7200.11, but it does with the 750GB 7200RPM Samsungs. A 4x boost in small block performance is nothing to sneeze at.

 

[Stereodude]

1.5TB Seagate 7200.11 (ICH9R) #2:

 

[Stereodude]

1.5TB Seagate 7200.11 (Perc 6/i) #1:


Stranger still... The Perc 6/i has great write performance, but the Read performance is a little odd. There's nothing like consistency. :lol:

 

[Stereodude]

1.5TB Seagate 7200.11 (Perc 6/i) #2:


I'm testing a RAID-1 array on the Perc 6/i now. :bomb:

 

[Stereodude]

2 x 1.5TB Seagate 7200.11 RAID-1 (Perc 6/i):


I guess it's good enough that I'll go with this card. :scratch:

 

[Stereodude]

2 x 1.5TB Seagate 7200.11 RAID-1 (Intel ICH9R):