Optimal stripe block size for this application?

[apriest]

Hey Guys & Gals,

Here?s something for y?all to mull over. I?m building a workstation for Lightwave rendering. http://www.newtek.com/products/lightwave/index.php Here are the specs of the new workstation:

• Lian-Li PC-71 Black Case

• Enermax EG651P-VE FM(24P) 550W Power Supply, Supports EPS 12V, necessary for motherboard

• Tyan S2665ANF Thunder i7505 Dual Xeon Motherboard, 2 mPGA604 CPU w/ 533MHz FSB, Hyper-Threading Support, 2 64-bit 100MHz 3.3v PCI-X, 1 64-bit 133MHz 3.3v PCI-X, 2 32-bit 33MHz 5v PCI, 1 8x AGP Pro50 1.5v, 4 184-pin 2.5v PC2100 DDR DIMM (up to 4GB RAM), 1 IEEE1394 FireWire, 1 Intel 82540EM 1000Mbps LAN, 4 USB 2.0, 6-Channel Audio w/ SPDIF, Intel E7505 Chipset

• Two Intel Xeon 2.4GHz Retail Box w/ Fan, PGA package, 604 pins, .13µ, 512 KB L2 Cache, 533MHz FSB, Supports Hyper-Threading and Dual Processing

• Two Kingston KVR266X72C2/512 512MB 266MHz DDR PC2100 ECC DIMM CAS2 (1GB total)

• ATI Radeon 9500 Pro, 8x AGP, 128MB DDR, DVI & CRT connectors, TV out

• Promise Technology SuperTrak SX4000 Pro Ultra ATA/100 RAID Controller, RAID 0, 1, 0+1, or 5, 4 ATA/133 Channels, 32-bit/66MHz PCI, Supports up to 256MB Cache

• Kingston KVR100X72C2L/256 256MB Low Profile PC100 ECC DIMM CL2 (for RAID controller)

• Five Western Digital WD1200JB, 120GB, 7200 RPM, 8.9ms, Ultra ATA/100, 8MB Cache. 1 system drive, 4 in RAID 0+1 config for rendering storage.

• Lite-On XJHD-166 Black 16x DVD-ROM / 48x CD-ROM

• WinXP Pro

• Two NEC AccuSync 95F, 19" Flat Screen Monitor, .25dpi diagonal, .20dpi horizontal, 1600x1200

This thing should render outrageously fast in Lightwave, compared to what we have anyway. Now my question is this: what stripe block size would be fastest for this application? I have a choice of 16, 32, or 64K, the default being 64K. Block sizes are still something that I have no knowledge about. Is there a formula you should go on, based on hard drive sizes, RAID level, average file size, or hard drive activity? I?d hate to re-create the array 5 or 6 times and test it under each environment; I don?t have that kind of time unfortunately. It goes into production Monday (if I can get it all built tomorrow)! What do y?all suggest?

 

[LeadMagnet]

16k - because any files you have that are under 16k - TMP , TXT , INI , INF , LOG , ect .... will take one entire stripe block by themselves.

or a 17k file would take two 16k stripe blocks. It's just more effecient use of space. Buying fast drives with larger cache sizes that are defragmented regularly would give you a greater performance boost than the stripping size. also the fastest you can get would be a RAID 0+1 configuration using a hardware RAID controller.

 

[apriest]

Well, this will have a separate system drive, where temp files and smaller sizes would be. The other 4 drives will be in a RAID 0+1 config. Each drive has an 8MB cache, and the controller itself (XOR processor) will have 256MB. Probably nothing on this array will be smaller than 100MB. Many of the files will be nearly a gig or more. It sounds like 64K block size might work fine. What would be any drawbacks of going 16K though?

 

[chizow]

What would be any drawbacks of going 16K though?

None really. You would see a slight performance edge using larger stripes when working with larger files. That's all.

Chiz

 

[sharkeeper]

Promise Technology SuperTrak SX4000 Pro Ultra ATA/100 RAID Controller, RAID 0, 1, 0+1, or 5, 4 ATA/133 Channels, 32-bit/66MHz PCI, Supports up to 256MB Cache


Kingston KVR100X72C2L/256 256MB Low Profile PC100 ECC DIMM CL2 (for RAID controller)


Five Western Digital WD1200JB, 120GB, 7200 RPM, 8.9ms, Ultra ATA/100, 8MB Cache. 1 system drive, 4 in RAID 0+1 config for rendering storage.

Dual Channel Ultra320 SCSI RAID10 would be better. 73GB 10K drives aren't that expensive...

EDIT: Please excuse my ignorance for not answering the question or giving some input!

Don't even try to calculate stripe sized based on your applications, and especially by the drive's buffer and the cache that's present on the HBA! Real calculations are possible, but trust me they will make your head hurt! :Q If possible, ask what the manufacturer recommends. Most will tell you 8K or 64K. IME, 64K works the best. You could create an image of the OS with Ghost and try every stripe size available but you will most likely find that 64KB is what you would stick with.

Cheers!

 

[apriest]

Originally posted by: shuttleteam

Dual Channel Ultra320 SCSI RAID10 would be better. 73GB 10K drives aren't that expensive...

I would have loved to have done Ultra320 and RAID 5+0 or something (what is RAID 10 again?), but to get that many drives to hit this size would have been quite expensive. I was originally looking at 4x200GB, but my customer dropped it to 4x120GB for the RAID at the last minute to cut more cost. This whole system is costing less than $3,500. That was our limit. :Q