Have you ever overclocked ? These Intel CPU's are known for their ability to jump up quite a bit in clock speed .
According to MSI's supported CPU list for the board you can use either of these
I think these are the top tier for this board , but i'm not up on intel stuff so i posted all the core 2 and quad stuff below . It will also run celerons and pentium class cpu's
QX9770 Core 2 Extreme
Q9505S Core 2 Quad
Q9500 Core 2 Quad
Core 2 Duo Conroe SL9S9 E6400 266 2.13 2M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SL9S8 E6600 266 2.40 4M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SL9S7 E6700 266 2.66 4M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SL9SA E6300 266 1.86 2M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SL9TA E6300 266 1.86 2M N/A L2 65 7512v10.zip
Core 2 Duo Conroe SL9ZF E6700 266 2.66 4M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SL9ZL E6600 266 2.40 4M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SL9T9 E6400 266 2.13 2M N/A L2 65 7512v10.zip
Core 2 Duo Conroe SL9TB E4300 200 1.80 2M N/A L2 65 7512v10.zip
Core 2 Duo Conroe SLA4U E6320 266 1.86 4M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SLA3F E4400 200 2.00 2M N/A L2 65 7512v10.zip
Core 2 Duo Conroe SLA4T E6420 266 2.13 4M N/A B2 65 7512v10.zip
Core 2 Duo Conroe SLAA5 E6540 333 2.33 4M N/A G0 65 7512v10.zip
Core 2 Duo Conroe SLA9X E6550 333 2.33 4M N/A G0 65 7512v10.zip
Core 2 Duo Conroe SLA9V E6750 333 2.66 4M N/A G0 65 7512v10.zip
Core 2 Duo Conroe SLA9U E6850 333 3.00 4M N/A G0 65 7512v10.zip
Core 2 Duo Conroe SLA95 E4500 200 2.20 2M N/A M0 65 7512v10.zip
Core 2 Duo Conroe SLA98 E4400 200 2.00 2M N/A M0 65 7512v10.zip
Core 2 Duo Conroe SLA94 E4600 200 2.40 2M N/A M0 65 7512v10.zip
Core 2 Duo Wolfdale SLAPP E8200 333 2.66 6M N/A C0 65 7512v10.zip
Core 2 Duo Conroe SLALT E4700 200 2.60 2M N/A G0 65 7512v10.zip
Core 2 Duo Wolfdale SLAPL E8400 333 3.00 6M N/A C0 65 7512v10.zip
Core 2 Duo Wolfdale SLAPN E8300 333 2.83 6M N/A C0 65 7512v10.zip
Core 2 Duo Wolfdale SLAPK E8500 333 3.16 6M N/A C0 65 7512v10.zip
Core 2 Duo Wolfdale SLAQR E8190 333 2.66 6M N/A C0 65 7512v10.zip
Core 2 Duo Wolfdale SLAPC E7200 266 2.53 3M N/A M0 65 7512v10.zip
Core 2 Duo Wolfdale SLB9L E8600 333 3.33 6M N/A E0 65 7512v11.zip
Core 2 Duo Wolfdale SLAPB E7300 266 2.66 3M N/A M0 65 7512v12.zip
Core 2 Duo Wolfdale SLB9K E8500 333 3.16 6M N/A E0 65 7512v12.zip
Core 2 Duo Wolfdale SLB9J E8400 333 3.00 6M N/A E0 65 7512v14.zip
Core 2 Duo Wolfdale SLB9Y E7400 266 2.80 3M N/A R0 65 7512v14.zip
Core 2 Duo Wolfdale SLB9Z E7500 266 2.93 3M N/A R0 65 7512v15.zip
Core 2 Duo Wolfdale SLGTD E7600 266 3.06 3M N/A R0 65 7512v16.zip
Core 2 Duo Wolfdale SLGW3 E7400 266 2.80 3M N/A R0 65 7512v16.zip
Core 2 Duo Wolfdale SLGTE E7500 266 2.93 3M N/A R0 65 7512v16.zip
Core 2 Extreme Conroe SL9S5 X6800 266 2.93 4M N/A B2 75 7512v10.zip
Core 2 Extreme Kentsfield SL9UL QX6700 266 2.66 8M N/A B3 130 7512v10.zip
Core 2 Extreme Kentsfield SL9UK QX6800 266 2.93 8M N/A B3 130 7512v10.zip
Core 2 Extreme Kentsfield SLACP QX6800 266 2.93 8M N/A G0 130 7512v10.zip
Core 2 Extreme Kentsfield SLAFN QX6850 333 3.00 8M N/A G0 130 7512v10.zip
Core 2 Extreme Yorkfield SLAN3 QX9650 333 3.00 12M N/A C0 130 7512v10.zip
Core 2 Extreme Yorkfield SLAWN QX9650 333 3.00 12M N/A C1 130 7512v10.zip
Core 2 Extreme Yorkfield SLAWM QX9770 400 3.20 12M N/A C1 136 7512v10.zip
Core 2 Quad Kentsfield SL9UM Q6600 266 2.40 8M N/A B3 105 7512v10.zip
Core 2 Quad Kentsfield SLACR Q6600 266 2.40 8M N/A G0 95 7512v10.zip
Core 2 Quad Kentsfield SLACQ Q6700 266 2.66 8M N/A G0 95 7512v10.zip
Core 2 Quad Yorkfield SLAWR Q9450 333 2.66 12M N/A C1 95 7512v10.zip
Core 2 Quad Yorkfield SLAWE Q9300 333 2.50 6M N/A M1 95 7512v10.zip
Core 2 Quad Yorkfield SLAWQ Q9550 333 2.83 12M N/A C1 95 7512v10.zip
Core 2 Quad Yorkfield SLB5M Q8200 333 2.33 4M N/A M1 95 7512v12.zip
Core 2 Quad Yorkfield SLB6B Q9400 333 2.66 6M N/A R0 95 7512v12.zip
Core 2 Quad Yorkfield SLB8W Q9650 333 3.00 12M N/A E0 95 7512v12.zip
Core 2 Quad Yorkfield SLB8V Q9550 333 2.83 12M N/A E0 95 7512v14.zip
Core 2 Quad Yorkfield SLB5W Q8300 333 2.50 4M N/A R0 95 7512v14.zip
Core 2 Quad Yorkfield SLG9T Q8200S 333 2.33 4M N/A R0 65 7512v15.zip
Core 2 Quad Yorkfield SLG9U Q9400S 333 2.66 6M N/A R0 65 7512v15.zip
Core 2 Quad Yorkfield SLGAE Q9550S 333 2.83 12M N/A E0 65 7512v15.zip
Core 2 Quad Yorkfield SLG9S Q8200 333 2.33 4M N/A R0 95 7512v16.zip
Core 2 Quad Yorkfield SLGT6 Q8400 333 2.66 4M N/A R0 95 7512v16.zip
Core 2 Quad Yorkfield SLGT7 Q8400S 333 2.66 4M N/A R0 65 7512v16.zip
Core 2 Quad Yorkfield SLGUR Q8300 333 2.50 4M N/A R0 95 7512v16.zip
Core 2 Quad Yorkfield SLGYY Q9505 333 2.83 6M N/A R0 95 7512v16.zip
Core 2 Quad Yorkfield SLGYZ Q9505S 333 2.83 6M N/A R0 65 7512v16.zip
Core 2 Quad Yorkfield SLGZ4 Q9500 200 2.83 6M N/A R0 95 7512v16.zip