Biostar

Yes, it will support by Ubuntu 12.1.

Due to chipset limitation for B75 chipset, it will only be able to support one analog display for output.

So B75MU3+ cannot use DVI to D-Sub converter for support two analog display at same time.

However, it still be able to support on-board D-Sub+DVI or D-Sub+HDMI® or DVI+HDMI® combination for dual display output.

Windows 8 system require Execute Bit function for Intel CPU.

Please enable the CPU's Execute Bit function in BIOS, then the problem should be resolved.

However, if your CPU does not have this function, then it will not be able to support Windows 8 system.

Please install Windows 7 system if your Intel CPU does not support Execute Bit function.

Our motherboard will be able to support USB boot function.
By using USB converter to connect SATA DVD drive to USB port will be able to detect by motherboard BIOS and install Windows 7/8.
Then 4 SATA ports on board will be able to run under RAID configuration.

Go to CMOS> Chipset> North bridge >GFX configuration> Intergrated graphics, then set to [Force].

Then it will be able to select share memory size for on-board VGA.

1. Set memory frequency to 2133 MHz and reboot the system.

2. Go to CMOS again and set CPU FSB to 113 MHz.

Memory will be able to OC to 2400 MHz by these setting.

Yes, A55ML+ DVI port will be able to support video output with sound to HDMI® monitor.

If motherboard is socket AM2+, then it will not be able to insert socket AM2 CPU.

So these two sockets' and CPU cannot compatible to each other.

Please refer CPU support page for proper CPU for each model.

BIOS will only display CPU L2 Cache size per core.

Each of CPU core on A4-3300 or A4-3400 has 512 KB of L2 cache size.

Total of 1 MB (1024 KB) L2 cache size for each CPU.

Here is the recommendation list for AMD FM2 CPU to enable Dual Graphic (Hybrid Crossfire) function.

A10: HD 6670 or HD 6570

A8: HD 6670 or HD 6570

A6: HD 6570 or HD 6450