Slow IDE with Nforce3

[Tim Schmidt]

I have terminally slow IDE (between 500k/s and 1Mb/s) on a pretty
generic Nforce3 board.  After som research it looks like it's due to
ide_generic being loaded instead of amd74xx for handling the PATA
controller.  Is there any way to specify loading amd74xx instead of
ide_generic on boot while still using the official kernel?  I've tried
aappending hda=amd74xx to the grub kernel line...  no dice.

The funny thing is that hdparm allows me to turn on DMA, etc without
complaint.  Here's the settings:

/dev/hda:
 multcount    = 16 (on)
 IO_support   =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 59554/16/63, sectors = 60030432, start = 0

Here's my lspci output:

0000:00:00.0 Host bridge: nVidia Corporation nForce3 250Gb Host Bridge (rev a1)
0000:00:01.0 ISA bridge: nVidia Corporation nForce3 250Gb LPC Bridge (rev a2)
0000:00:01.1 SMBus: nVidia Corporation nForce 250Gb PCI System
Management (rev a1)
0000:00:02.0 USB Controller: nVidia Corporation CK8S USB Controller (rev a1)
0000:00:02.1 USB Controller: nVidia Corporation CK8S USB Controller (rev a1)
0000:00:02.2 USB Controller: nVidia Corporation nForce3 EHCI USB 2.0
Controller (rev a2)
0000:00:05.0 Bridge: nVidia Corporation CK8S Ethernet Controller (rev a2)
0000:00:06.0 Multimedia audio controller: nVidia Corporation nForce3
250Gb AC'97 Audio Controller (rev a1)
0000:00:08.0 IDE interface: nVidia Corporation CK8S Parallel ATA
Controller (v2.5) (rev a2)
0000:00:0a.0 IDE interface: nVidia Corporation CK8S Serial ATA
Controller (v2.5) (rev a2)
0000:00:0b.0 PCI bridge: nVidia Corporation nForce3 250Gb AGP Host to
PCI Bridge (rev a2)
0000:00:0e.0 PCI bridge: nVidia Corporation nForce3 250Gb PCI-to-PCI
Bridge (rev a2)
0000:00:18.0 Host bridge: Advanced Micro Devices [AMD] K8
[Athlon64/Opteron] HyperTransport Technology Configuration
0000:00:18.1 Host bridge: Advanced Micro Devices [AMD] K8
[Athlon64/Opteron] Address Map
0000:00:18.2 Host bridge: Advanced Micro Devices [AMD] K8
[Athlon64/Opteron] DRAM Controller
0000:00:18.3 Host bridge: Advanced Micro Devices [AMD] K8
[Athlon64/Opteron] Miscellaneous Control
0000:01:00.0 VGA compatible controller: nVidia Corporation NV35
[GeForce FX 5900XT] (rev a1)
0000:02:08.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394
Host Controller (rev 46)