I have this same problem, though it definitely seems to be complicated. Copying large files (>2GB) from one SATA drive to another, or to another location on the same drive pretty much seems to always cause slow speeds (and i mean like 3Mb/sec, it can take 20-30 mins to copy a 4gig file, its seriously faster to burn the same file). Copying a say, 700MB file between the same two drives is reasonably fast (~30mb/sec).
I have a mix of NTFS and reiserfs drives, but it doesnt seem to matter which are the source and target drives. For what its worth, I had the same problem in gentoo, and 32 vs 64-bit doesnt seem to matter either. I'm fairly sure this is a kernel bug, possibly related to specific motherboards or chipset (i'm using the onboard SATA of my nforce4 board). I dont have any of the obvious problems mentioned earlier like disabled write cache or no DMA modes enabled, hdparm gives me a 72MB/s reads (is there a way to test writes?).
It's frustrating to know that I have drives capable of 50+MB/sec, and dont seem to have a problem getting those speeds in windows, and can only get half that in linux at best. Anyone with any insight would be much appreciated.
I have this same problem, though it definitely seems to be complicated. Copying large files (>2GB) from one SATA drive to another, or to another location on the same drive pretty much seems to always cause slow speeds (and i mean like 3Mb/sec, it can take 20-30 mins to copy a 4gig file, its seriously faster to burn the same file). Copying a say, 700MB file between the same two drives is reasonably fast (~30mb/sec).
I have a mix of NTFS and reiserfs drives, but it doesnt seem to matter which are the source and target drives. For what its worth, I had the same problem in gentoo, and 32 vs 64-bit doesnt seem to matter either. I'm fairly sure this is a kernel bug, possibly related to specific motherboards or chipset (i'm using the onboard SATA of my nforce4 board). I dont have any of the obvious problems mentioned earlier like disabled write cache or no DMA modes enabled, hdparm gives me a 72MB/s reads (is there a way to test writes?).
It's frustrating to know that I have drives capable of 50+MB/sec, and dont seem to have a problem getting those speeds in windows, and can only get half that in linux at best. Anyone with any insight would be much appreciated.