One user's experiences with RAID 0 and RAID 5

[stevech]

Here's an interesting post from user Ray on the forums at extremetech.com
His experiences with RAID 0 and RAID 5

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I cant answer the question about the Intel Matrix or Marvell Raid performance.

But I can comment on the performance of the arrangements I have tried

System Asus A8n-SLI Premium, 2G DDR400, winfast 7800 graphics. XP 64bit. FIle size is typically 1-4GBtye Video files.

2x 500G samsung Raid0 on the NVidia port & 8x 500G Samsung Raid 5 on the Highpoint 2320 PCI-eX in a 4x slot.

Test method is to copy a block of about 10, greater than 1GB files from one array to the other and use windows performance monitor to measure the physical disk read and write in bytes/second. Visual average over the length of time to copy the files.

Previous test results.

4x 200G Raid 5 Array on the Asus A8n-SLI Premium NVidia port. Windows Raid 5, read about 75MB/s, Write <25MB/s

4x 300G Raid 5 Array on the Asus A8n-SLI Premium SIL 3114 port. Hardware Raid 5, Read about 70MB's, Write <15MB/s

6x 300G PATA Raid 5 on Rocket Raid 454 PCI Card. Read about 70-80MB/s, Write <15MB/s

Current setup.

2x 500G samsung Raid0 on the NVidia port to the 8x 500G Samsung Raid 5 on the Highpoint 2320 PCI-eX in a 4x slot.

Read NV Raid >130MB/s (HDTach), copy from Highpoint to NV Raid, average 80MB/s, peak >120MB/s

Copy from NV Raid to Highpoint, Average 100MB/s, peak >110MB/s

One thing that makes a huge difference with the Highpoint Array is to turn NQC off on each disk on the raid 5 array and turn "write back" on.

HDTach 3.01 went from about <60MB/s to >130MB/s.

Also be prepared to have a backup strategy in place should you chose to grow the Highpoint array from 6 to 8 disks as I did. Windows lost the partition after the ORLM was finished. And I had to use the old 6x 300G disks to recover the data to before recreating the GPT partition and reformatting. It's taken the best part of a week to recover 2TB. Only half was mirrored on another PC.

So conclusion. Get as many disks as you can. Beware >2TB needs XP 64bit or Vista. And buy a decent card if you want speed.

Ray