Re: dropped frames, slow raid write rates

Jason,

8 drives should yield more than 160mbs, I would check to see if you have a slow or failing or even failed drive in the mix.

I can't totally speak for how this all works in the MAC world but I can say from MANY years of experience that slow arrays stem from several reasons no matter what they are connected to. If you were once able to capture uncompressed with that array (which I do believe you were) then something has gone amuck.

Simply suggesting to drop to a COMPRESSED format like ProRes isn't a good suggestion (Maybe this guy really needs uncompressed). It is a fairly decent codec but it isn't uncompressed quality by an means.

Here are some suggestions and if all else fails you could always call in help from people like Bob Zelin, who make a living doing this on the MAC.

Again, I can only make suggestions based on what I am familiar with here

Does the hard drive controller in your system allow for configuration? If so a wrong setting will certainly effect drive speeds.

A controller in an improper slot in the Mobo, or one that is contention with another device will certainly cause problems (drop frames being a big one)

Again, physical drive issues in the array. Drives are not designed to just sit for lengthy periods of time once they have been in use. Drives have gotten better over the years but I am guessing your array is several years old :)

Capturing the wrong flavor of uncompressed with an array that isn't fast enough. For example there is a huge difference in needed thruput for 8bit YcbCr (YUV) than for 10bit RGB.

Try wiping your array clean and re-formating.

Hope that helps a bit, good luck

Ramona







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