When working with VMware ESXi 4.0 on Intel platforms with VT-d capability, passing through native SATA drives can be particularly tricky. The Intel DX58S0 motherboard's 88SE6121 controller presents specific challenges that require careful configuration.

Before proceeding with passthrough configuration, verify:

1. VT-d is enabled in BIOS
2. ESXi detects the controller under Storage Adapters
3. No existing datastores are using the target drives
4. The controller appears in the PCI devices list (esxcli hardware pci list)

Here's the exact procedure I've successfully used with similar hardware:

# First, identify the PCI device ID
esxcli hardware pci list | grep -i 88SE6121

# Mark the device for passthrough
vim-cmd hostsvc/devices | grep -i 88SE6121
vim-cmd hostsvc/devices.passthrough "device_id" true

# Reboot the ESXi host to apply changes

When the guest OS doesn't detect passed-through drives:

• Verify the controller is properly reset during passthrough (check dmesg in Linux guests)
• Test with different SATA operation modes (AHCI usually works best)
• Ensure no BIOS-level RAID configuration is active

If direct controller passthrough proves problematic, consider these workarounds:

# Raw Device Mapping (RDM) alternative:
vmkfstools -z /vmfs/devices/disks/naa.xxxxxxxx /vmfs/volumes/datastore/rdm.vmdk

# Then add the RDM to your VM configuration file (.vmx):
scsiX:Y.present = "TRUE"
scsiX:Y.fileName = "/vmfs/volumes/datastore/rdm.vmdk"
scsiX:Y.deviceType = "scsi-hardDisk"

When benchmarking both methods on my test system:

For optimal performance with passed-through SATA controllers:

# In the VMX file, add these parameters:
pciPassthru.use64bitMMIO = "TRUE"
pciPassthru.64bitMMIOSizeGB = "4"
pciPassthru.msiEnabled = "FALSE"

These settings help prevent memory mapping issues that can occur with older chipsets like the 88SE6121.

When working with ESXi 4.0 on Intel platforms with VT-d capability, passing through native SATA controllers presents unique challenges. The Intel DX58S0 motherboard's 88SE6121 controller behavior differs significantly from modern AHCI implementations.

Before attempting passthrough, verify these critical requirements:

# Check VT-d activation in ESXi
esxcfg-info | grep -i "VT-D"
# Expected output: "VT-D: Supported and Enabled"

# List available PCI devices
lspci -v | grep -i "sata"

The complete process involves multiple layers of configuration:

# 1. Enable PCI passthrough in ESXi configuration
/etc/vmware/esx.conf:
/pciPassthru/0/ids = "1b4b 6121"
/pciPassthru/0/present = "true"
/pciPassthru/0/function = "0"
/pciPassthru/0/device = "6121"
/pciPassthru/0/vendor = "1b4b"
/pciPassthru/0/name = "Marvell 88SE6121"

Add these parameters to your VMX file:

pciPassthru0.present = "TRUE"
pciPassthru0.deviceId = "0x6121"
pciPassthru0.vendorId = "0x1b4b"
pciPassthru0.functions = "8"
scsi0:0.present = "FALSE" # Remove virtual controller if conflicting

For Windows guests, you'll need to:

1. Download Marvell 88SE6121 drivers from Intel
2. Inject during installation using DISM
3. Configure storage controller in IDE compatibility mode

Common issues and solutions:

# Check dmesg output in Linux guests
dmesg | grep -i "marvell"

# Verify IRQ assignments
cat /proc/interrupts | grep -i "sata"

# Alternative approach using RDM (Raw Device Mapping)
vmkfstools -z /vmfs/devices/disks/naa.XXXXXXXXXXXXXXXX -a lsilogic MyVM/rdm0.vmdk

After successful passthrough, consider these tweaks:

# Set queue depth in Linux
echo 64 > /sys/block/sdX/queue/nr_requests

# Windows registry tweaks
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\disk]
"EnableCounterForIoctl"=dword:00000000