Performance quandry

[Sovereign]

Problem: Transfer rates between hard drives are extremely poor!

First off, the motherboard is an nForce 4 AMD Edition SLI 16x Asus A8N32-SLI Deluxe. The hard drives are Western Digital 2500KS (16MB cache, SATA300MB/sec) and a single Western Digital 7500AAKS (16MB cache, 300MB/sec).

The problem is transfer rates between the 750GB drive and the dual 250GB drives. With the OS (Vista Ultimate x64) idle, a transfer from the 750GB to one of the 250GB (not in RAID anymore, using the big 750GB to un-RAID the 250GB drives without losing data or burning huge numbers of discs) reads transfers at 20MB/sec, no more. In RAID0, the transfer rates from the 500GB RAID0 topped at 50MB/sec to the 750GB drive.

Naturally, with 300GB+ of data to move this is frustrating as it makes the whole backup/restore process take an obscene amount of time. It took 2 hours just to dump the RAID0 array to the 750GB drive! Average was about 45MB/sec (maximum 79MB/sec, minimum 20MB/sec).

I have tried re-installing the latest nVidia chipset drivers to no avail. Horrible transfer speeds are making this un-RAID a nightmare! Help!

[KnightRid]

Before typing I will remind you of my stupidity.

Now, that said....shouldnt the transfer rates from 1 drive be half what the raid array was anyway since you cant read from both drives at once?

Mike

1 other thing, and it sounds even more stupid ( stupider ) - try removing both the 250gb drives after transferring everything to the 750, then restart, then shut down and install 1 drive, restart, then shut down and install the other, then restart again. Ignore sata being hot swappable etc.

Sounds like a pain in the arse, but I had a slow 120gb drive until I did this exact same thing - just reinstalled each drive other than the boot drive one by one, and then it worked - well formatting each one in between using FULL format not quick also.

stupid out.

[Sovereign]

Yes the transfers are half what the RAID array were, but since the RAID array could barely top 40MB/sec, something was very wrong anyway

I'll try swapping out drives then, thanks, I would have not thought of that.

The RAID array was not compressed. Do compressed files inhibit performance this much? I formatted the volumes as NTFS Compressed but am uncompressing them now.

[kenc51]

Writing to a RAID 0 array is slower than reading and never works out a double the performance of a single drive. This is because on-board controllers are software based.

~40mb/sec does sound slow though, you should be in the high 50's or mid 60's.

Have you installed the latest motherboard bios and OS drivers?

[toolegit2quit]

Def sounds like a bios / OS device manager issue. Of course if you had a handy alternate system to benchmark the drives on it would illiminate the raid being the issue.