RAM utilization by Starwind? Any advantage to adding ram?

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stever@bitshop.com
Posts: 3
Joined: Sun Aug 07, 2005 6:46 am
Location: Ashburn, VA

Fri Dec 16, 2005 6:29 am

Do you have any research showing a graph of ram to performance for a “average” iSCSI server? We’re speccing out a 15 drive system , dual opteron and wondering if RAM would really be used or should we just go with maybe 2gb (max is 16gb in server).

I’m not sure how well windows / starwind will take advantage of the ram is why this question - I know windows will use it if it's there, but will Starwind itself take advantage of it any at all?

I do know it’s kind of a hard to answer question, depending on the data on this server, but just a average benchmark of how it does, specifically through starwind (incase that changes any NT cache algorithms) would be very helpful. Perhaps a standard benchmark run against a server trying it with 1 gb, 2gb, 4gb, 8gb of ram and seeing the difference.
Val (staff)
Posts: 496
Joined: Tue Jun 29, 2004 8:38 pm

Fri Dec 16, 2005 5:49 pm

Hi Steve,

We have not yet tested Starwind with dirrerent RAM sizes, but knowing its architecture I'd like to say that huge amount of memory will not give you much better performance of StarWind.
It depends on the type of the device you are testing (for RamDisks the more RAM the bigger disk you are able to create;).

In most of the scenarios StarWind allocates memory only for its request descriptor packets and temporary data buffers. It does not cache data sectors in memory and tends to use unbuffered file I/O where possible.
So having 1-2GB of memory on your test machine should be enough.

Looking from the perfomance point of view it's much better to get more processor power or more processors in the server. This will definitely encrease the total throughput.
Best regards,
Valeriy
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