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NOTE: FSX AND RAID-0

Posted:
Sun Jul 08, 2007 11:28 pm
by Nick N
If you do not use RAID for MSFS or do not know what RAID is, ignore this post.
If you do use RAID-0 on a TWO drive RAID system please note:
SET YOUR STRIPE SIZE TO NO LESS THAN 128K DURING ARRAY CREATION
IF YOUR SYSTEM IS A DEDICATED FSX MACHINE SET THE STRIPE TO 256K IF THE BIOS WILL ALLOW IT OTHERWISE SET IT TO 128K
IF YOU
Re: NOTE: FSX AND RAID-0

Posted:
Mon Jul 09, 2007 12:50 am
by macca22au
NickN: I do have a 2 drive system, in RAID 0 configuration. However it was set up for me in the shop. Can you give me an amateurs guide to setting up the stripe size. Although my machine is used principally for FS it is also a general purpose machine as well, so I suppose that I would need to setup the 128K stripe.
This is fascinating to me, as I have noticed that on loading FSX my machine at times has both cores at a 100%.
It would be ironic if many of the stutter problems that seem insoluble can be sheeted back to this problem.
Re: NOTE: FSX AND RAID-0

Posted:
Mon Jul 09, 2007 7:32 am
by garymbuska
I have heard of this happening with other programs as well. I am not sure as why it might have something to do with the dual core processors but that is just a wild guess. I am not using RAID so I can not hlep you with the setup but it does sound like NickN has come accross something here. 8-)
Re: NOTE: FSX AND RAID-0

Posted:
Mon Jul 09, 2007 9:50 am
by Nick N
To set the stripe size requires the entire install be destroyed, the disks re-striped in the RAID boot BIOS and the system completely reloaded.
The motherboard manual explains the process.
The problem with FSX is it uses very large file sets as compare to FS9. The average file size in FS9 was 49k-256Kb, in FSX that jumps significantly to 696K-2MB
RAID0 works by breaking up the file so you get the advantage of 2 heads reading the file data, however, in order for that to work correctly the user MUST set up the correct STRIPE size for the file system being used.
Anyone in IT that has a brain knows that when running a sequential read file system it is best to run a higher RAID stripe, and random access system, lower size stripe. With the use of O&O and other defrag software that runs a COMPLETE/NAME defrag you turn your disk into a sequential read optimized unit.
Therefore, you want a larger stripe. What that number should be is based on the file sizes being read. With FS9 that was around 128k when you average 49-256k for textures and other files.
Here is the math
Re: NOTE: FSX AND RAID-0

Posted:
Mon Jul 09, 2007 7:59 pm
by macca22au
So now I understand why my tech had convulsions at the suggestion. I think he also headed quickly to a local bar to get some immediate fortification.
In reality, Nick, I would need to be really convinced to do this, as I would have to pay my computer shop to do the job.
For you it is time and interest. For me it is money - and my wife is asking about my preference - her or the computer.
We've been married 48 years and the opportunity cost of being single no longer stacks up!
However when I can afford it I intend to put another 8800 GTX card in. They claim that even without the game supporting SLI the system splits the rendering between the two - and with matrox that might be beneficial.
So when I do that I will do the other. Then I might earn my stripes (poor joke).
Re: NOTE: FSX AND RAID-0

Posted:
Mon Jul 09, 2007 10:12 pm
by garymbuska
[quote]To set the stripe size requires the entire install be destroyed, the disks re-striped in the RAID boot BIOS and the system completely reloaded.
The motherboard manual explains the process.
The problem with FSX is it uses very large file sets as compare to FS9. The average file size in FS9 was 49k-256Kb, in FSX that jumps significantly to 696K-2MB
RAID0 works by breaking up the file so you get the advantage of 2 heads reading the file data, however, in order for that to work correctly the user MUST set up the correct STRIPE size for the file system being used.
Anyone in IT that has a brain knows that when running a sequential read file system it is best to run a higher RAID stripe, and random access system, lower size stripe. With the use of O&O and other defrag software that runs a COMPLETE/NAME defrag you turn your disk into a sequential read optimized unit.
Therefore, you want a larger stripe. What that number should be is based on the file sizes being read. With FS9 that was around 128k when you average 49-256k for textures and other files.
Here is the math
Re: NOTE: FSX AND RAID-0

Posted:
Tue Jul 10, 2007 1:59 am
by Nick N
[quote]So now I understand why my tech had convulsions at the suggestion.
Re: NOTE: FSX AND RAID-0

Posted:
Wed Jul 11, 2007 12:50 am
by macca22au
Incidentally is there a simple diagnostic that will tell me what the stripe size is? With my quite new Asus Gigabyte board I might in fact have a 128K stripe?
Re: NOTE: FSX AND RAID-0

Posted:
Wed Jul 11, 2007 12:54 am
by macca22au
Oh and the Soundblaster does give vastly improved sound.
It is the best audio CD player in the house, and it plays Messaien and Saint-Saens pipe organ music to enormous effect with the subwoofer doing the lower registers with style.
And turbine sounds are now great deep rumbles that are almost indecently exciting.
Re: NOTE: FSX AND RAID-0

Posted:
Wed Jul 11, 2007 5:53 pm
by AnGeL_MaKeR
I'm currently running two S-ATA Drives at 250 GB each.
Re: NOTE: FSX AND RAID-0

Posted:
Wed Jul 11, 2007 7:40 pm
by macca22au
For an experiment, is it possible to disable RAID 0 without going through a full reinstall of the OS and everything else?
Re: NOTE: FSX AND RAID-0

Posted:
Wed Jul 11, 2007 7:50 pm
by justpassingthrough
Ahhhhh CRAP!
I just saw this thread. I need to check in more often
So I guess that means Im DUCKED? I know I cant go any higher than 64K.
Maybe that why I have been fighting this for so long! Just when it seems like I got it nailed, something else tips it just enough to make it start stuttering or blur. Same with getting it set up in one area and have it not fly right at all in another which would make sense because the scenery tiles change and the load changes with it.
DANG IT!!!
I might just install FSX to another single SATA hard drive and see if it makes a difference
macca22au, no.. it can not be disabled. RAID0 will fall apart if you try to split the drives and you can never recover. Once you break a RAID0 array apart, the data is lost unless you have expensive recovery software but even that only gets parts of the files back. You wont ever boot from the drive again without a complete reinstall on a new array and stripe
your tech should have warned you that if anything goes wrong with a RAID-0 drive, ANYTHING... you loose EVERYTHING instantly
RAID-1 is the only secure RAID out there, or RAID 0 + 1 but you loose the very high perfomance advantage
Re: NOTE: FSX AND RAID-0

Posted:
Wed Jul 11, 2007 8:02 pm
by macca22au
Thanks. Yes I was aware of the risks of RAID 0, and accepted them to get the performance. I was only wondering whether it could be disabled but that is clearly not the case.
I guess those of us with RAID 0 do, or should do, a lot of backing up on to other media. Certainly I put all my photographs - Digital photography and Photoshop are my antidote to too much FSX - on to CD or DVD. Also downloaded games with their licence files.
Re: NOTE: FSX AND RAID-0

Posted:
Thu Jul 12, 2007 12:08 pm
by justpassingthrough
[quote]Thanks.
Re: NOTE: FSX AND RAID-0

Posted:
Thu Jul 12, 2007 11:00 pm
by macca22au
Wives certainly get in the way of simming - but if they work it makes it easier to find some cash for the next video card, cpu, motherboard, RAM and all those other essentials of life (like scenery and aircraft add-ons).