PTaylor's WebLog

Phil

Many are using RAID for FSX. RAID if properly set up can decrease the overhead on the CPU created by disk I/O, however, if improperly set up it will INCREASE the I/O and cause stutters, blurs and other issues because the system is busy dealing with a RAID array that has fragmented the FSX files to the point of having to seek 20-30 times more than a it should.

FSX should NEVER be set up on a 2 disk RAID array that has a STRIPE or BLOCK size of less than 128K. Optimally it should be 256K or 512K. Even 128K creates a high number of seeks per file and one should use 4 drives for a 128K stripe.

Anything less and it is pointless/useless and detrimental to run FSX on a RAID array.

The resulting blurs and stutters can never be compensated for without significantly reducing the scenery/traffic/autogen sliders.

Please make note of that. It is the same for SATA or SCSI RAID. Speed matters not, the amount of I/O does because FSX is so CPU bound anything can tip the scales in that area.

Consumer level motherboard RAID rarely allows greater than 128K stripes be used. Professional RAID can allow as high as 4096K. Since the typical public does not understand RAID and its proper use, many of the issues that go back to scenery problems on what would be considered very high quality systems can be linked back to the issue of low stripe and/or only 2 drives in the array.

Thanks Phil, I'll give this a whirl as the default block size that my Asus board chose was 64K on a 500GB (2 x 250GB) stripe. So currently re-installing on a separate 250GB drive and will post back if difference is noticeable.

pablo1974

Please be aware that in order to see advantages or disadvantages between the two you must also make sure the file system is properly defragemented. I highly suggest you use one of 2 programs; O&O DEFRAG or ULTIMATE DEFRAG and set the defrag programs to run COMPLETE\NAME order defragment passes.

The Windows defrag, Perfect Disk, Diskeeper, etc do NOT do a proper sequential defrag of the file system, only the 2 products I mention will. I use O&O Defrag.

Run the defrag program making sure NO POWER SAVE options are enabled, set the computer to ALWAYS ON and make sure there is no screen saver or disk power-down set to timeout.

Once the first defrag has completed, reboot the computer and run it again.

Do not touch the system for any reason while the defrag program is running.

High Stripe RAID likes a sequential access file system. By running a NAME defrag you are placing all the files on the system in sequential order. It is critical the defrag be run at least 2 times with reboots in between, I run it 3 the first time I install a system.

Going back to what I said about the stripe, 128K is the lowest I would run on a 2 disk array for FSX but that is even restrictive. 256K would be much better, or increase the number of drives in the 128K array.

FSX is not good for single core processors unless you have a 3 ghz speed or something like that.  I have a amd 64 athlon 2.2 ghz overclocked and a nvidia 128 mb video card.  And FSX Ran very choppy. But that was without SP1.  I also have a dell duo core processor  that I just purchased, and FSX Ran choppy on that too had to tweak a lot of the settings and I still wasn't happy with it.  But when I installed SP1 it fixed the problem it runs very smooth the graphics aren't turned all the way up but its tuned up enough to where its awesome enough for me.  Honestly with FSX you wouldn't be able to max out the graphics unless you had a 512mb graphics card or greater dell makes a 768mb graphics card and a Quad Core Processor is ideal I think then you could max everything out.  I had a physics accelerator put in my dell but I don't know if it contributes to FSX or not.  If someone knows  please let me know about the physics accelerator

I have a quad core and a 768mb graphics card and I still can't max everything out.  FSX defaults to Ultra High on all the settings but when you actually check them, even at Ultra High, there is still a lot of slider off to the right for lots of settings.