System info:

$ lspci

01:00.0 VGA compatible controller: NVIDIA Corporation NV44 [GeForce 6500] (rev a1)

$ free -m

             total       used       free     shared    buffers     cached

Mem:          7940       7646        294         49        168       3908

-/+ buffers/cache:       3568       4372

Swap:         8143          0       8143

cpu:

vendor_id   : GenuineIntel

cpu family  : 6

model       : 42

model name  : Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz

stepping    : 7

microcode   : 0x25

cpu MHz     : 1600.000

cache size  : 8192 KB

$ sudo lshw -short

H/W path        Device      Class          Description

======================================================

                            system         System Product Name (SKU)

/0                          bus            P8H77-M LE

/0/0                        memory         64KiB BIOS

/0/4                        processor      Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz

/0/4/5                      memory         32KiB L1 cache

/0/4/6                      memory         256KiB L2 cache

/0/4/7                      memory         8MiB L3 cache

/0/1                        memory         

/0/1/0                      memory         4GiB DIMM DDR3 Synchronous 1333 MHz (0,8 ns)

/0/58                       memory         System Memory

/0/58/0                     memory         4GiB DIMM DDR3 Synchronous 1333 MHz (0,8 ns)

/0/2                        memory         

/0/3                        memory         

/0/100                      bridge         2nd Generation Core Processor Family DRAM Controller

/0/100/1                    bridge         Xeon E3-1200/2nd Generation Core Processor Family PCI Express Root Port

/0/100/1/0                  display        NV44 [GeForce 6500]

/0/100/14                   bus            7 Series/C210 Series Chipset Family USB xHCI Host Controller

/0/100/16                   communication  7 Series/C210 Series Chipset Family MEI Controller #1

/0/100/1a                   bus            7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2

/0/100/1b                   multimedia     7 Series/C210 Series Chipset Family High Definition Audio Controller

/0/100/1c                   bridge         7 Series/C210 Series Chipset Family PCI Express Root Port 1

/0/100/1c.5                 bridge         7 Series/C210 Series Chipset Family PCI Express Root Port 6

/0/100/1c.5/0   eth0        network        RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller

/0/100/1c.6                 bridge         82801 PCI Bridge

/0/100/1c.6/0               bridge         ASM1083/1085 PCIe to PCI Bridge

/0/100/1d                   bus            7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1

/0/100/1f                   bridge         H77 Express Chipset LPC Controller

/0/100/1f.2                 storage        7 Series/C210 Series Chipset Family 6-port SATA Controller [AHCI mode]

/0/100/1f.3                 bus            7 Series/C210 Series Chipset Family SMBus Controller

/0/5            scsi0       storage        

/0/5/0.0.0      /dev/sda    disk           500GB WDC WD5000AAKX-0

/0/5/0.0.0/1    /dev/sda1   volume         243MiB Linux filesystem partition

/0/5/0.0.0/2    /dev/sda2   volume         465GiB Extended partition

/0/5/0.0.0/2/5  /dev/sda5   volume         465GiB Linux LVM Physical Volume partition

/0/6            scsi4       storage        

/0/6/0.0.0      /dev/cdrom  disk           CDDVDW SH-222BB

/1                          power          To Be Filled By O.E.M.

Installed nvidia-304 proprietary driver.

The system sometimes getting extremely slow especially performing desktop video effects (all those fade-ins and fade-outs, blurs, etc.)

Previously I had Ubuntu 10.04 and I didn't have any issues with performance.

Is this due to poor video card which is scored just 68 at glmark2 test?
What can I do to improve overall performance?