Is there a reason why writing to an external HDD via eSATA would be considerably slower than reading back from same. When I write files to this external drive it seems to pause intermittently while using eSATA which slows down transfer time, yet using USB connection it goes smoothly without the pauses. The external drive is a WD7500AACS (one of those "Green Power" drives) so I don't know if this is normal behavior for this drive or I should consider returning it. Everything else seems to be OK with this HDD...runs very quiet and cool...no bad sectors...did a full format just to check. I just can't understand why it reads back much faster than it writes using eSATA. Also I don't know if SATA I/II setting has anything to do with it (I use a PCI card with 150 speed and it's possible the HDD is set for 300 speed but I can't open the case without voiding the warranty). Tried 3 different eSATA cables, same result. Also have used another external eSATA case with same setup and that one has no such problem as this (but this one I know the drive inside is jumpered for 150 speed). So at this point I don't know if I have a defective hard drive, defective eSATA port on the enclosure, wrong jumper setting for SATA I/II speed, or something else. Anyone have any suggestions on what I can check?
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E-SATA runs on SATA II so I'm assuming your PCI 150 speed prevents it from actually running it at the 300 spd. you may want to consider buying a E-SATA PCI CONTROLLER CARD.
I'm using this PCI card (my mobo is IDE only), but judging by the poor reviews on Newegg maybe this card is the problem.
Though this card works fine with Antec MX-1 enclosure.
I think I would replace the PCI card. You should notice only a slight difference, if at all, with a SATA 150 compared to a SATA 300 card as far as read/write speed goes. eSATA is basically a cable and connector improvement. Otherwise it should perform the same as regular SATA. It could also be the controller in your external case. I would replace the card first and if you have the same problems, then the external enclosure or drive.
The Rosewill or IoGear cards are cheap enough and should be a better setup. I also recommend the Silicon Image chipset cards.
One last thing to try before you give up with your present setup is to move the PCI card to a different slot. On older motherboards, the slot directly below the video card shares IRQs with the video card. Definitely not the place to use a high speed card. Even without that, sometimes moving the card to a different slot can make a difference.
You're probably better off with a E-SATA PCI CONTROLLER CARD that has a SILICON IMAGE CHIPSET. I've learned that chipsets on controller cards do make a big difference when it comes to compatibility on hardware such as hard drives and optical drives.
Here's one that supports 3.0gbs for SATA II. But the one below only is internal esata.
Here's one that has external SATA II and it supports 3.0gbs.
Is there any way to check which chipset the external enclosure is using for eSATA without opening the case? Maybe there could be a firmware update or something. I don't think there's anything wrong with the HDD itself since USB works OK and eSATA works fine when sending data out, just that sending data in via eSATA seems slower than USB sometimes due to pauses during transfer. It almost seems like it is verifying the data written or something the way it pauses and the light on the enclosure flickers different colors for a few seconds then resumes. Device manager identifies the drive as WDC WD7500AACS-00ZJB SCSI Disk Device. Not sure what the -00ZJB stands for. Write caching options are grayed out (but locked on "optimize for performance"). Tried updating the driver for the Initio chipset on the PCI card, but no improvement.
Just tried moving the PCI card to another slot, and the PC couldn't find the card at all. Probably not a good card. Ordered a Rosewill card with Silicon Image chip to try out.