I'm running a fresh installed Ubuntu 12.04 LTS with ext4 on a SSD 520 by Intel. My mainboard is an ASUS Crosshair (latest BIOS 1207) with a Sil 3132 SATA Controller which claims to support SATAII. I have TRIM enabled. But my results are pretty bad in comparison to what could be expected:

sudo hdparm -Tt /dev/sda



/dev/sda:

 Timing cached reads:   2510 MB in  2.00 seconds = 1255.51 MB/sec

 Timing buffered disk reads: 376 MB in  3.00 seconds = 125.21 MB/sec

Is my mainboard bottlenecking it? Here are some info about the SSD in use:

sudo hdparm -I /dev/sda

/dev/sda:



ATA device, with non-removable media

    Model Number:       INTEL SSDSC2CW120A3                   

    Serial Number:      CVCV227301JE120BGN  

    Firmware Revision:  400i    

    Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0

Standards:

    Used: unknown (minor revision code 0x0110) 

    Supported: 9 8 7 6 5 

    Likely used: 9

Configuration:

    Logical     max current

    cylinders   16383   16383

    heads       16  16

    sectors/track   63  63

    --

    CHS current addressable sectors:   16514064

    LBA    user addressable sectors:  234441648

    LBA48  user addressable sectors:  234441648

    Logical  Sector size:                   512 bytes

    Physical Sector size:                   512 bytes

    Logical Sector-0 offset:                  0 bytes

    device size with M = 1024*1024:      114473 MBytes

    device size with M = 1000*1000:      120034 MBytes (120 GB)

    cache/buffer size  = unknown

    Nominal Media Rotation Rate: Solid State Device

Capabilities:

    LBA, IORDY(can be disabled)

    Queue depth: 32

    Standby timer values: spec'd by Standard, no device specific minimum

    R/W multiple sector transfer: Max = 16  Current = 1

    Advanced power management level: 254

    DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 

         Cycle time: min=120ns recommended=120ns

    PIO: pio0 pio1 pio2 pio3 pio4 

         Cycle time: no flow control=120ns  IORDY flow control=120ns

Commands/features:

    Enabled Supported:

       *    SMART feature set

            Security Mode feature set

       *    Power Management feature set

       *    Write cache

            Look-ahead

       *    Host Protected Area feature set

       *    WRITE_BUFFER command

       *    READ_BUFFER command

       *    NOP cmd

       *    DOWNLOAD_MICROCODE

       *    Advanced Power Management feature set

            Power-Up In Standby feature set

       *    SET_FEATURES required to spinup after power up

       *    48-bit Address feature set

       *    Mandatory FLUSH_CACHE

       *    FLUSH_CACHE_EXT

       *    SMART error logging

       *    SMART self-test

       *    General Purpose Logging feature set

       *    WRITE_{DMA|MULTIPLE}_FUA_EXT

       *    64-bit World wide name

       *    IDLE_IMMEDIATE with UNLOAD

       *    WRITE_UNCORRECTABLE_EXT command

       *    {READ,WRITE}_DMA_EXT_GPL commands

       *    Segmented DOWNLOAD_MICROCODE

       *    Gen1 signaling speed (1.5Gb/s)

       *    Gen2 signaling speed (3.0Gb/s)

       *    Native Command Queueing (NCQ)

       *    Host-initiated interface power management

       *    Phy event counters

       *    unknown 76[14]

            DMA Setup Auto-Activate optimization

            Device-initiated interface power management

       *    Software settings preservation

       *    SMART Command Transport (SCT) feature set

       *    SCT Data Tables (AC5)

       *    Data Set Management TRIM supported (limit 1 block)

       *    Deterministic read data after TRIM

Security: 

    Master password revision code = 65534

        supported

    not enabled

    not locked

    not frozen

    not expired: security count

        supported: enhanced erase

    4min for SECURITY ERASE UNIT. 2min for ENHANCED SECURITY ERASE UNIT.

Logical Unit WWN Device Identifier: 5001517bb29a74d4

    NAA     : 5

    IEEE OUI    : 001517

    Unique ID   : bb29a74d4

Checksum: correct