Is this normal?
Clicked A Few Times
1:00:35 PM PST - Sat, Nov 24th 2012
Hi,

I did two experiments with the same input file (QA/tests/cytosine_ccsd) on 4 processors.

On the first experiment, the application files are on a hard disk drive, whereas on the second I moved the application into an solid state drive.

I noticed that the runtime of the application the same in both cases, and even it's better (slightly) on the hard disk! Is this normal? Any reason to explain that?

Forum Vet
10:11:32 AM PST - Mon, Nov 26th 2012
This suggests to me that the calculation is not restricted because of bandwidth.

Bert


Quote:Dhaminah Nov 24th 8:00 pm
Hi,

I did two experiments with the same input file (QA/tests/cytosine_ccsd) on 4 processors.

On the first experiment, the application files are on a hard disk drive, whereas on the second I moved the application into an solid state drive.

I noticed that the runtime of the application the same in both cases, and even it's better (slightly) on the hard disk! Is this normal? Any reason to explain that?

Clicked A Few Times
2:10:14 PM PST - Mon, Nov 26th 2012
Could you please elaborate more?

Forum Vet
3:08:16 PM PST - Mon, Nov 26th 2012
I'm a little confused that you ask this question as I seem to remember you are a computer science graduate student.

If the I/O bandwidth of standard hard drive is enough to load data from disk, then additional bandwidth from a solid state drive won't make any difference.

Bert


[QUOTE=Dhaminah Nov 26th 9:10 pm]Could you please elaborate more?[/quote]

Clicked A Few Times
5:10:08 PM PST - Mon, Nov 26th 2012
I just wanted to confirm that what you said is what I thought about as well - I was a bit confused because sometimes the application runs a bit slower on SSD than on conventional disk.


Thanks for your time...



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