1T of course will give better result without doubt.
2T is a significantly slower than 1T in AMD64 system because of integrated memory controller. Xcrue, normally, for us to understand better the actual behavior of the RAM, there is a program called Sisoft Sandra. No matter what settings that you set, you can keep an eye on whether it improves or degrade performance by looking at the memory bandwidth.

Hope my suggestion helps though...

It's a simple mod, get someone whois familar with soldering to do it for you.

1T or 2T is command rate similar to CPC ON or CPC OFF.
To simplify, 1T is faster dude.....

Command Rate CMD (1/ 2) (Command Rate, MA 1T/2T Select)
Number of clock cycles needed to address the memory module and the memory chip with the desired data zone. If your memory banks (slots) are full to capacity, you will have to raise this rate to two, resulting in a considerable drop in performance.

http://www.obm.co.nz/obmnew/guides/ddrram.htm

DRAM command rate specifies the time to wait after a chip select before activate and read can be started. It is usually suggested that you apply the lowest command rate that your RAM and motherboard can run stable with. The lesser the value, the quicker the memory controller be able to send commands out. On the other hand, at higher frequencies it might be crucial to raise the command rate latency in order to get your system at super stable state.