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US15W IDE driver


The US15W spec mentions that DMA transfer modes are supported for storage devices. It also mentions there is a SATA > IDE bridge chip.

Under Win7, this is detected as a Standard IDE Controller using the standard Microsoft driver. After installation of the Intel chipset drivers for US15W, no changes are made to the IDE controller.

The performance of this with an Atom Z520 @ 1.33Ghz is poor to say the least, even with a 7200 rpm Western Digital Caviar Black, transfer rates are 2 - 3Mb/s. This was upgraded from a stock Seagate 5400 rpm, again transfer rate about 2Mb/s. Under the standard windows driver, only PIO Mode 4 is available and Use DMA is grayed out. CPU usage is high when reading/writing to the drives.

Are there drivers from Intel for this bridge chip that enable DMA transfer modes? If this is a third party bridge, what is the make/model?

Thanks in advance.

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2 Replies

The US15W has only a IDE interface. It does not provide SATA interfaces.

To implement SATA interfaces, a third party chip is required. This could be a IDE-to-SATA converter or a PCIe SATA device.

Either way, for the IDE interface of the US15W, there seem to be no Intel drivers. However, they are not necessary because the standard drivers should work fine.

Have you checked your BIOS settings yet? Maybe they are set to allow PIO modes only. It might also help to uninstall all IDE devices in the Device Manger and reboot.


Hi, thanks for replying.

This is on a Dell Mini 1010, with the HDMI interface. The BIOS (latest) does not allow selectable hard drive functions as to supported modes.

I was aware that a bridge was being used but it was unclear whether this was supplied by Intel as part of the chipset or a third party add-on by the hardware OEM.

Either way performance using the "Standard IDE Controller" under Win7 is poor, with UDMA modes unavailable. I might be wrong but this is the first Intel chipset that does not have a proper storage driver in a long time, not sure why. Even if not necessary to work usually Intel at least release an inf file that identifies the controller properly. Is the lack of driver on this platform solely due to the need for a third party bridge for storage?