separate hard drives = no encoding performance gain

[supaidaaman]

I just got set up with a new core i7 940, evga x58, 12gb ram, vista64, gtx285

onboard - intel controller
2x 640gb drives in raid0
150gb 10k raptor for OS

onboard - seperate jmicron controller
640gb external drive connected through esata


here is the strange thing. No matter what drive im rendering to or from, the speeds are the same across the board. Except in adobe media encoder, its fastest when rendering from the raid0 to the same raid0. ???????

Now everything about that seems completely wrong. At my home I have a raid0 and raptor. Rendering to another drive is ALWAYS faster. I get slower speeds at home rendering from and to the same drive....but somehow on this new work build it makes no difference.

Does anyone have an idea? Im trying to come up with a plan to tell people the performance benefit of having multiple drives....when clearly...on this system there is none.

 

[Phynaz]

When you say rendering, I'm going to assume you mean video re-encoding?

What makes you think a relatively low bandwidth operation like this would benefit from fast disks?

 

[supaidaaman]

Im rendering from AE/Premeire and then re-encoding files to different formats. These are 1920x1080 files, some of which are almost lossless.

My other work computer gets a benefit of up to 3x the rendering/encoding speed by simply rendering to a separate raid array/drive.

I assumed that this would be true for this build.

 

[HendrixFan]

I was encoding a 170GB file in Huffyuv to x264 and I had all four cores (8 with HT on) maxed out at 100%. My bottleneck was my processor speed during the encode process.

I have always found faster drives more useful during the editing process than the encode process. What is your setup on your other work computer?

Edit: Just had another thought. Maybe your RAM was maxed out before (certainly not now with 12GB) and Windows was using the hard drive swap to help and that really slowed things down.

 

[Yellowbeard]

Try manipulating your hardware setup a little and see what happens.

Cut back to 4GB of RAM

Drop CPU speed to slowest possible.

See if any of this effects your encoding times. If it's not changing between the various drive combinations then apparently your HD thruput is not a bottleneck.

 

[supaidaaman]

hmm.

According to HD tune my raid0
read min is 109
max 195
average 167
access time 15.4
burst rate 113.8

that seems a bit low to me?

 

[HendrixFan]

If that is for the 640Gb drives that sounds about right. Most reviews online show them maxing out around 96MB/s which sounds like your max doubled. The average is 83MB/s per drive, which seems about right. Access time is reasonably good, RAID will always slow that down.

 

[pjkenned]

Just as a thought, I do lots of 1080 video editing and x264 encoding... Stuff that kills performance is really the lack of sufficient amounts of RAM and CPU speed. And the Core i7 w/ HT is sometimes more than twice as fast as the old Core 2 Quad when both are at 3.6Ghz. I will say that when you are doing the 1920x1080 video that is 2GB/ 90s that can be challenging for the disk I/O, but remember that is still under 23MB/s of bandwidth, largely sequential read/write. When you have to move the final product to/from disk to disk you will of course use lots more bandwidth assuming the source/target is at least as fast.

Hands down though, CPU and RAM size are going to be the big factors that you will notice speed up your performance, and right now the i7 is just spectacular at most of those applications with semi-mature multi-threading.