我想换个CPU，选什么型号的呢？

你这个主板是很老的945芯片组，只支持LGA775的CPU

他能支持的CPU有这些：
Celeron 420(1.60GHz,800 FSB,L2 512KB,LGA775,revA1) ALL 0902

Celeron 430(1.80GHz,800 FSB,L2 512KB,LGA775,revA1) ALL 0902

Celeron 440(2.00GHz,800 FSB,L2 512KB,LGA775,revA1) ALL 0902

Celeron D 351 (3.2 GHz, 533 FSB, LGA775)E0,EM64T ALL 0202

Celeron D 352 (revC1,65nm,3.20 GHz, 533 FSB, L2:512KB, LGA775) ALL 0202

Celeron D 355 (3.33 GHz, 533 FSB, L2:256KB, revG1, LGA775) ALL 0202

Celeron D 356 (65nm,3.33 GHz, 533 FSB, L2:512KB, revD0, LGA775) ALL 0202

Celeron D 356 (revB1, 65nm,3.33 GHz, 533 FSB, L2:512KB, LGA775) ALL 0202

Celeron D 356 (revC1,65nm,3.33 GHz, 533 FSB, L2:512KB, LGA775) ALL 0202

Celeron Dual Core E1200(revM0,1.6GHz,800 FSB,L2:512K) ALL 1002

Celeron Dual Core E1500(revM0,2.2GHz,800 FSB,L2: 512K) ALL 1002

Core 2 Duo E4300 (1.8GHz,800FSB,L2:2MB,65W,rev.L2) ALL 0803

Core 2 Duo E4400 (2.0GHz,800FSB,L2:2MB,65W,rev.L2) ALL 0501

Core 2 Duo E4500 (2.2GHz,800FSB,L2:2MB,65W,rev.M0) ALL 0904

Core 2 Duo E4600 (2.4GHz,800FSB,L2:2MB,65W,rev.M0) ALL 0904

Core 2 Duo E4700 (2.6GHz,800FSB,L2:2MB,revG0) ALL 1002

Core 2 Duo E6300 (1.86GHz,1066FSB,L2:2MB,rev.B2) ALL 0202

Core 2 Duo E6320 (1.86GHz,1066FSB,L2:4MB,rev.B2) ALL 0801

Core 2 Duo E6400 (2.13GHz,1066FSB,L2:2MB,rev.B2) ALL 0202

Core 2 Duo E6420 (2.13GHz,1066FSB,L2:4MB,rev.B2) ALL 0801

Core 2 Duo E6600 (2.40GHz,1066FSB,L2:4MB,rev.B2) ALL 0202

Core 2 Duo E6700 (2.66GHz,1066FSB,L2:4MB,rev.B2) ALL 0202

Core 2 Extreme X6800(2.93GHz,1066FSB,L2:4MB,revB2) ALL 0202

P4-3.73 GHz Extreme Ed. (1066 FSB, HT, revN0, LGA775) ALL 0202

P4-515 (2.93 GHz) (533 FSB)(E0,D0) ALL 0202

P4-516 (2.93 GHz) (533 FSB, EM64T)(D0,E0) ALL 0202

P4-530/530J (3E GHz) (800 FSB) (D0,E0) ALL 0202

P4-551 (3.4GHz, 800 FSB, L2 1MB,D0,E0) ALL 0202

P4-571 (3.8GHz, 800 FSB, L2 1MB V E0) ALL 0202

P4-631 (65nm,3.0GHz, 800 FSB, L2:2MB, revB1) ALL 0202

P4-631 (65nm,3.0GHz, 800 FSB, L2:2MB, revC1) ALL 0202

P4-641 (65nm,3.2GHz, 800 FSB, L2:2MB, revB1) ALL 0202

P4-641 (65nm,3.2GHz, 800 FSB, L2:2MB, revC1) ALL 0202

P4-661 (65nm,3.6GHz, 800 FSB, L2:2MB, revB1) ALL 0202

P4-661 (65nm,3.6GHz, 800 FSB, L2:2MB, revC1) ALL 0202

P4-670 (3.8 GHz, 800 FSB, L2:2MB,N0) ALL 0202

P4-672 (3.8 GHz, 800 FSB, L2:2MB, revR0) ALL 0202

Pentium D 805 (2.66 GHz, 533 FSB, revB0) ALL 0202

Pentium D 820 (2.8 GHz, 800 FSB, revA0) ALL 0202

Pentium D 820 (2.8 GHz, 800 FSB, revB0) ALL 0202

Pentium D 830 (3.0 GHz, 800 FSB, revA0) ALL 0202

Pentium D 830 (3.0 GHz, 800 FSB, revB0) ALL 0202

Pentium D 840 (3.2 GHz, 800 FSB, revA0) ALL 0202

Pentium D 840 (3.2 GHz, 800 FSB, revB0) ALL 0202

Pentium D 915(2.8GHz, 800 FSB, L2 4MB, revC1, without VT function) ALL 0202

Pentium D 915(2.8GHz, 800 FSB, L2 4MB, revD0,without VT function) ALL 0202

Pentium D 920(2.8GHz, 800 FSB, L2 4MB, revB1) ALL 0202

Pentium D 925(3.0GHz, 800 FSB, L2 4MB, revC1, without VT function) ALL 0202

Pentium D 925(3.0GHz, 800 FSB, L2 4MB, revD0, without VT function) ALL 0202

Pentium D 930(3.0GHz, 800 FSB, L2 4MB, revB1) ALL 0202

Pentium D 930(3.0GHz, 800 FSB, L2 4MB, revC1) ALL 0202

Pentium D 935(3.2GHz, 800 FSB, L2 4MB, 95W, revD0) ALL 0202

Pentium D 940(3.2GHz, 800 FSB, L2 4MB, revB1) ALL 0202

Pentium D 940(3.2GHz, 800 FSB, L2 4MB, revC1) ALL 0202

Pentium D 945(3.4GHz, 800 FSB, L2 4MB, revC1, without VT function) ALL 0202

Pentium D 945(3.4GHz, 800 FSB, L2 4MB, revD0, without VT function) ALL 0202

Pentium D 950(3.4GHz, 800 FSB, L2 4MB, revB1) ALL 0202

Pentium D 950(3.4GHz, 800 FSB, L2 4MB, revC1) ALL 0202

Pentium D 950(3.4GHz, 800 FSB, L2 4MB, revD0) ALL 0202

Pentium D 960(3.6GHz, 800 FSB, L2 4MB, revC1) ALL 0202

Pentium D 960(3.6GHz, 800 FSB, L2 4MB, revD0) ALL 0202

Pentium Dual Core E2140(1.6GHz, 800FSB, L2 1MB,L2) ALL 0803

Pentium Dual Core E2140(1.6GHz,800FSB,L2 1MB,M0) ALL 0904

Pentium Dual Core E2160(1.8GHz, 800FSB, L2 1MB,L2) ALL 0803

Pentium Dual Core E2180(2.0GHz,800FSB,L2 1MB,M0) ALL 0904

Pentium Dual Core E2200(2.2GHz,800FSB,L2 1MB,M0) ALL 0904

Pentium Dual Core E2220(2.4GHz,800FSB,L2 1MB,M0) ALL 0904

Pentium Extreme ED-965(3.73GHz, rev C1)

官方网站的支持列表：http://www.asus.com.cn/Motherboards/P5PL2E/HelpDesk_CPU/

建议你要买就买E4300，不过你这套配置是在太老了，换CPU提升不大，最好都换了吧

Model GA-945PL-S3G
PCB 1.0
Vender Model FSB 1066
Intel Core™ 2 Extreme QX9770(C1,Yorkfield,45nm,3.2GHz,12 MB) 1600 -
Intel Core™ 2 Extreme QX9770(C0,Yorkfield,45nm,3.2GHz,12 MB) 1600 -
Intel Core™ 2 Extreme QX9650(C1,Yorkfield,45nm,3GHz,12 MB) 1333 -
Intel Core™ 2 Extreme QX9650(C0,Yorkfield,45nm,3GHz,12 MB) 1333 -
Intel Core™ 2 Quad Q9650(E0,Yorkfield,45nm,3.0 GHz,12MB) 1333 -
Intel Core™ 2 Quad Q9550(E0,Yorkfield,45nm,2.83GHz,12MB) 1333 -
Intel Core™ 2 Quad Q9550s(E0,Yorkfield,45nm,2.83GHz,12MB) 1333 -
Intel Core™ 2 Quad Q9550(C1,Yorkfield,45nm,2.83GHz,12MB) 1333 -
Intel Core™ 2 Quad Q9505s(R0,Yorkfield,45nm,2.83GHz,6MB) 1333 -
Intel Core™ 2 Quad Q9505(R0,Yorkfield,45nm,2.83GHz,6MB) 1333 -
Intel Core™ 2 Quad Q9450(C1,Yorkfield,45nm,2.66GHz,12MB) 1333 -
Intel Core™ 2 Quad Q9400(R0,Yorkfield,45nm,2.66GHz,6MB) 1333 -
Intel Core™ 2 Quad Q9400s(R0,Yorkfield,45nm,2.66GHz,6MB) 1333 -
Intel Core™ 2 Quad Q9300(M1,Yorkfield,45nm,2.50GHz,6MB) 1333 -
Intel Core™ 2 Quad Q8400(R0,Yorkfield,45nm,2.66GHz,4MB) 1333 -
Intel Core™ 2 Quad Q8400s(R0,Yorkfield,45nm,2.66GHz,4MB) 1333 -
Intel Core™ 2 Quad Q8300(R0,Yorkfield,45nm,2.50GHz,4MB) 1333 -
Intel Core™ 2 Quad Q8200(M1,Yorkfield,45nm,2.33GHz,4MB) 1333 -
Intel Core™ 2 Quad Q8200(R0,Yorkfield,45nm,2.33GHz,4MB) 1333 -
Intel Core™ 2 Quad Q8200s(M1,Yorkfield,45nm,2.33GHz,4MB) 1333 -
Intel Core™ 2 Duo E8600(E0,Wolfdale,45nm,3.33GHz,6MB) 1333 -
Intel Core™ 2 Duo E8500(C0,Wolfdale,45nm,3.16GHz,6MB) 1333 -
Intel Core™ 2 Duo E8500(E0,Wolfdale,45nm,3.16GHz,6MB) 1333 -
Intel Core™ 2 Duo E8400(C0,Wolfdale,45nm,3GHz,6MB) 1333 -
Intel Core™ 2 Duo E8400(E0,Wolfdale,45nm,3GHz,6MB) 1333 -
Intel Core™ 2 Duo E8300(C0,Wolfdale,45nm,2.83GHz,6MB) 1333 -
Intel Core™ 2 Duo E8200(C0,Wolfdale,45nm,2.66GHz,6MB) 1333 -
Intel Core™ 2 Duo E8190(C0,Wolfdale,45nm,2.66GHz,6MB) 1333 -
Intel Core™ 2 Extreme QX6850(G0,Kentsfield,65nm,3GHz,8MB) 1333 -
Intel Core™ 2 Extreme QX6800(G0,Kentsfield,65nm,2.93GHz,8MB) 1066 -
Intel Core™ 2 Extreme QX6700(B3,Kentsfield,65nm,2.66GHz,8MB) 1066 -
Intel Core™ 2 Extreme X6800(B2,Conroe XE,65nm,2.93GHz,4MB) 1066 -
Intel Core™ 2 Quad Q6700(G0,Kentsfield,65nm,2.66GHz,8MB) 1066 -
Intel Core™ 2 Quad Q6600(G0,Kentsfield,65nm,2.40HGz,8MB) 1066 -
Intel Core™ 2 Quad Q6600(B3,Kentsfield,65nm,2.40GHz,8MB) 1066 -
Intel Core™ 2 Duo E7600(R0,Wolfdale,45nm,3.06GHz,3MB) 1066 -
Intel Core™ 2 Duo E7500(R0,Wolfdale,45nm,2.93GHz,3MB) 1066 -
Intel Core™ 2 Duo E7400(R0,Wolfdale,45nm,2.8GHz,3MB) 1066 -
Intel Core™ 2 Duo E7300(M0,Wolfdale,45nm,2.66GHz,3MB) 1066 -
Intel Core™ 2 Duo E7200(M0,Wolfdale,45nm,2.53GHz,3MB) 1066 -
Intel Core™ 2 Duo E6850(G0,Conroe,65nm,3GHz,4MB) 1333 -
Intel Core™ 2 Duo E6750(G0,Conroe,65nm,2.66GHz,4MB) 1333 -
Intel Core™ 2 Duo E6700(B2,Conroe,65nm,2.66GHz,4MB) 1066 -
Intel Core™ 2 Duo E6600(B2,Conroe,65nm,2.40GHz,4MB) 1066 -
Intel Core™ 2 Duo E6550(G0,Conroe,65nm,2.33GHz,4MB) 1333 -
Intel Core™ 2 Duo E6540(G0,Conroe,65nm,2.33GHz,4MB) 1333 -
Intel Core™ 2 Duo E6420(B2,Conroe,65nm,2.13GHz,4MB) 1066 -
Intel Core™ 2 Duo E6400(L2,Conroe,65nm,2.13GHz,2MB) 1066 -
Intel Core™ 2 Duo E6400(B2,Conroe,65nm,2.13GHz,2MB) 1066 -
Intel Core™ 2 Duo E6320(B2,Conroe,65nm,1.86GHz,4MB) 1066 -
Intel Core™ 2 Duo E6300(L2,Conroe,65nm,1.86GHz,2MB) 1066 -
Intel Core™ 2 Duo E6300(B2,Conroe,65nm,1.86GHz,2MB) 1066 -
Intel Core™ 2 Duo E4700(G0,Conroe,65nm,2.60GHz,2MB) 800 -
Intel Core™ 2 Duo E4600(M0,Conroe,65nm,2.40GH,2MB) 800 -
Intel Core™ 2 Duo E4500(M0,Conroe,65nm,2.20GHz,2MB) 800 -
Intel Core™ 2 Duo E4400(M0,Conroe,65nm,2GHz,2MB) 800 -
Intel Core™ 2 Duo E4400(L2,Conroe,65nm,2GHz,2MB) 800 -
Intel Core™ 2 Duo E4300(L2,Conroe,65nm,1.80GHz,2MB) 800 -
Intel Pentium Dual-Core E6500(R0,Wolfdale,45nm,2.93GHz,2MB) 1066 -
Intel Pentium Dual-Core E6300(R0,Wolfdale,45nm,2.80GHz,2MB) 1066 -
Intel Pentium Dual-Core E5400(R0,Wolfdale,45nm,2.70GHz,2MB) 800 -
Intel Pentium Dual-Core E5300(R0,Wolfdale,45nm,2.60GHz,2MB) 800 -
Intel Pentium Dual-Core E5200(M0,Wolfdale,45nm,2.50GHz,2MB) 800 -
Intel Pentium Dual-Core E2220(M0,Conroe,65nm,2.40GHz,1MB) 800 -
Intel Pentium Dual-Core E2200(M0,Conroe,65nm,2.2GHz,1MB) 800 -
Intel Pentium Dual-Core E2180(M0,Conroe,65nm,2.0GHz,1MB) 800 -
Intel Pentium Dual-Core E2160(M0,Conroe,65nm,1.8GHz,1MB) 800 -
Intel Pentium Dual-Core E2160(L2,Conroe,65nm,1.8GHz,1MB) 800 -
Intel Pentium Dual-Core E2140(M0,Conroe,65nm,1.6GHz,1MB) 800 -
Intel Pentium Dual-Core E2140(L2,Conroe,65nm,1.6GHz,1MB) 800 -
Intel Celeron Dual-Core E3300(R0,Wolfdale,45nm,2.5GHz,1 MB) 800 -
Intel Celeron Dual-Core E3200(R0,Wolfdale,45nm,2.4GHz,1 MB) 800 -
Intel Celeron Dual-Core E1600(M0,Conroe,65nm,2.4GHz,512KB) 800 -
有些需要刷新bios 你主板是否提供 比你差的就不贴了

　　笔记本cpu是不能升级的，就算是更换也是更换相同型号的，
　　不跟台式机一样，可以随意更换插拔，笔记本cpu是焊接上去的。
　　而且楼主笔记本显卡也不好，图形性能垃圾到家，就算是神仙给你换个cpu，还是照样玩不成。
　　你就算低价买到CPU，焊一下的钱比你比卖二手笔记本的钱都多，你还是卖个版型一样的主板直接换上去实际。

建议不用换了，换下来性能提升也不是太明显。