How to Upgrade Your CPU

[nextpage title=”Introduction”]
This tutorial is for people that are willing to replace their CPU by a faster one but don’t have a clue on what CPUs their system supports. In this tutorial we will list all CPU models you can install on your system without replacing your current motherboard.
In order to upgrade your CPU you will need to know two things about your motherboard: its CPU socket and its maximum external clock rate (a.k.a. FSB, Front Side Bus – for AMD CPUs based on AMD64 architecture you don’t need this information). These two data are written on the motherboard manual. If you don’t have your motherboard manual, please read our tutorial How to Find Out Your Motherboard Manufacturer and Model.
There is one very important thing to note about motherboard manuals: usually they bring wrong information about what is the fastest processor you can install on your board. This happens because usually motherboard manuals are written well before all CPU models are available on the market, so your motherboard may accept a faster CPU than your motherboard manual is telling you.
You can only replace your CPU with another CPU that uses the same socket. Otherwise you will need to replace also your motherboard (and maybe other components, like memory, if your new motherboard requires a different kind of memory, for example).
On the next pages we will list all CPU upgrading options you have depending on the CPU socket your motherboard has.
Before replacing your CPU we strongly recommend you to perform a BIOS upgrade on your motherboard to update your motherboard with the latest available BIOS. Please read our How To Perform a BIOS Upgrade tutorial for further instructions. This will assure you that your motherboard will recognize your new CPU. Several times when you install a new CPU that you know that your motherboard supports your motherboard won’t turn on because it needs a BIOS upgrade, and you will have to install back your old CPU in order to do this. Avoid this hassle by performing a BIOS upgrade before replacing your CPU.
On our tutorial How to Correctly Apply Thermal Grease you will find detailed information on how to replace a CPU. Of course this procedure must be done with your computer turned off.
After replacing your CPU you will need to run a hardware identification utility such as Sandra, Hwinfo or CPU-Z to check whether your new CPU is running at its correct clock rate or not. If not, you will need to enter the motherboard setup (by pressing Del after turning your computer on) and change your CPU configuration there. This is usually necessary when you replace your current CPU by one that requires a higher external clock rate (FSB).
[nextpage title=”Socket 370″]
Well, if your motherboard is based on socket 370 this means you are in front of a very old computer based on Socket 370 Celeron or on Socket 370 Pentium III. Keep in mind that these CPUs are available for other sockets as well, so we are talking specifically about socket 370 models here. Socket 370 models can also be referred as PPGA or as FC-PGA. In order to know what is the fastest CPU you can install on your motherboard, you will need to know what is the maximum FSB clock rate your motherboard supports. Typical values are 66 MHz, 100 MHz and 133 MHz.
To make things simpler, we compiled the table below. At one side you have your motherboard FSB and on the other which CPUs are supported.

FSB	Celeron	Pentium III
66 MHz	All socket 370 models up to 766 MHz.	Not supported.
100 MHz	All socket 370 models, available up to 1.4 GHz.	All socket 370 models without a letter “B” on its name, available up to 1.1 GHz.
133 MHz	All socket 370 models, available up to 1.4 GHz.	All socket 370 models, available up to 1.2 GHz.

[nextpage title=”Socket 462″]
If your motherboard is based on socket 462 this means that your current CPU is an Athlon, an Athlon XP, a Duron or a Socket 462 Sempron. Socket 462 was also called Socket A in the past, so Socket 462 and Socket A are the same thing (do not confuse with Slot A). In order to know what is the fastest CPU you can install on your motherboard, you will need to know what is the maximum FSB clock rate your motherboard supports. Typical values are 200 MHz, 266 MHz, 333 MHz and 400 MHz.
Also keep in mind that Athlon XP and Sempron CPUs are not rated with their real clock rate but with a “performance index”. So an Athlon XP 2400+ does not run internally at 2.4 GHz, this “2400+” is just a “performance index” (in fact this CPU runs at 2 GHz).
To make things simpler, we compiled the table below. At one side you have your motherboard FSB and on the other which CPUs are supported. Pay attention because some motherboards supporting 333 MHz and 400 MHz can’t provide a 200 MHz FSB. You need to check on your motherboard manual if this is your case – if it is, your motherboard doesn’t support the installation of Athlon and Duron CPUs.
Also keep in mind that Sempron CPUs are also available for other socket types, so here we are talking only about the socket 462 version of this CPU.

FSB	Athlon	Duron	Athlon XP	Sempron
200 MHz	All models up to 950 MHz and models from 1 GHz to 1.4 GHz with 200 MHz FSB (these same models have a 266 MHz version, be careful).	All models up to 1.3 GHz.	Not supported.	Not supported.
266 MHz	All models (available up to 1.4 GHz).	All models (available up to 1.8 GHz).	All models up to 2400+ (2 GHz). There is also a 2600+ model that uses a 266 MHz FSB, but be careful because there is also a 2600+ model that uses 333 MHz FSB.	Not supported.
333 MHz	All models (available up to 1.4 GHz).	All models (available up to 1.8 GHz).	All models up to 2800+ (which can run at 2.08 GHz or at 2.25 MHz). There is also a 3000+ model that uses a 333 MHz FSB, but be careful because there is also a 3000+ model that uses 400 MHz FSB.	All socket 462 models (available up to 3000+, which runs at 2 GHz).
400 MHz	All models (available up to 1.4 GHz).	All models (available up to 1.8 GHz).	All models (available up to 3200+, which runs at 2.2 GHz).	All socket 462 models (available up to 3000+, which runs at 2 GHz).

For more information about all Athlon XP and Sempron socket 462 models available, we recommend you to read our Sempron vs. Athlon XP tutorial.
[nextpage title=”Socket 478″]
Socket 478 was used by Socket 478 Celeron, Socket 478 Celeron D, Socket 478 Pentium 4 and Socket 478 Pentium 4 Extreme Edition CPUs. Keep in mind that these CPUs are available for other sockets as well, so we are talking specifically about socket 478 models here. In order to know what is the fastest CPU you can install on your motherboard, you will need to know what is the maximum FSB clock rate your motherboard supports. Typical values are 400 MHz, 533 MHz, 800 MHz and 1,066 MHz.
To make things simpler, we compiled the table below. At one side you have your motherboard FSB and on the other which CPUs are supported. Pay attention because some newer motherboards supporting 533 MHz and above can’t provide a 400 MHz FSB. You need to check on your motherboard manual if this is your case – if it is, your motherboard doesn’t support the installation of Socket 478 Celeron CPUs.

FSB	Celeron	Celeron D	Pentium 4	Pentium 4 Extreme Edition
400 MHz	All socket 478 models, available up to 2.8 GHz.	Not supported.	All socket 478 models up to 2.20 GHz and the 2.50 GHz model. There are also 2.40 GHz, 2.60 GHz and 2.80 GHz models using a 400 MHz FSB, but be careful as these models are also available for other FSB’s.	Not supported.
533 MHz	All socket 478 models, available up to 2.8 GHz.	All socket 478 models, available up to 3.2 GHz (“350” model). *	All socket 478 models up to 2.80 GHz and the 3.06 GHz model. Please be careful as there are 2.80 GHz, 2.60 GHz and 2.40 GHz versions also available for the 800 MHz FSB. *	Not supported.
800 MHz	All socket 478 models, available up to 2.8 GHz.	All socket 478 models, available up to 3.2 GHz (“350” model). *	All socket 478 models, available up to 3.4 GHz. *	All socket 478 models up to 3.4 GHz.
1,066 MHz	All socket 478 models, available up to 2.8 GHz.	All socket 478 models, available up to 3.2 GHz (“350” model).	All socket 478 models, available up to 3.4 GHz.	All socket 478 models, available up to 3.73 GHz.

* Not all motherboards support Celeron D and Pentium 4 CPUs based on “Prescott” core (all Socket 478 Celeron D CPUs are based on this core). This happens because of the new power specs required by Prescott-based CPUs. So take a careful look at your motherboard manual to find out if it supports Prescott-based CPUs (look for “Prescott” and “Celeron D” – if it supports Celeron D this means it supports Pentium 4 “Prescott” CPUs) or not. Here you can find a full list of Pentium 4 CPUs that are based on Prescott core, which may not work on older motherboards. On this same tutorial there is a list of Pentium 4 CPUs based on Willamette and Northwood cores, which work on all motherboards with the proper FSB.
[nextpage title=”Sockets 754, 939, 940, AM2 and F”]
AMD processors based on AMD64 architecture use a different approach. As their memory controller is embedded inside the chip (instead of being located on the north bridge chip from the motherboard), they don’t use the FSB concept, making it very easy for you to upgrade your AMD64 CPU. AMD64 CPUs include Sempron (socket 754 and socket AM2 versions), Athlon 64, Athlon 64 X2, Athlon 64 FX and Opteron. As Opteron is a CPU targeted to servers, we won’t be covering this CPU on this tutorial.
Like all other CPUs you can only replace one CPU by another that uses the same socket type used by your motherboard. If you want to replace your CPU by another that uses a different socket, you will need to replace your motherboard as well (and sometimes also other devices, such as the RAM memory).
To make things simpler, we compiled the table below. At one side you have your motherboard socket and on the other which CPUs are supported.
Keep in mind that AMD64 CPUs are not rated with their real clock rate but with a “performance index”. So an Athlon 64 4000+ does not run internally at 4 GHz, this “4000+” is just a “performance index” (in fact this CPU runs at 2.4 GHz).
Since this table presents the current AMD CPUs available on the market, it may not have the latest models released (we will try to keep this table updated as much as we can).

Socket	Sempron	Athlon 64	Athlon 64 X2	Athlon 64 FX
754	All socket 754 models, available up to 3400+ (2 GHz).	All socket 754 models, available up to 3700+ (2.4 GHz)	Not supported.	Not supported.
939	Not supported.	All socket 939 models, available up to 4000+ (2.4 GHz)	All socket 939 models, available up to 4800+ (2.4 GHz).	All socket 939 models, available up to FX-60. *
940	Not supported.	Not supported.	Not supported.	All socket 940 models, available up to FX-53 (single-core, 2.4 GHz).
AM2	All socket AM2 models, available up to 3800+ (2.2 GHz)	All socket AM2 models, available up to 4000+ (2.6 GHz).	All socket AM2 models, available up to 6000+ (3 GHz)	So far only FX-62 (dual-core, 2.8 GHz).
F (1207)	Not supported.	Not supported.	Not supported.	All socket F models, available up to FX-74 (dual-core, 3 GHz).

* FX-60 runs at 2.6 GHz and is a dual-core CPU. FX-57 runs at 2.8 GHz but is a single-core CPU.
[nextpage title=”Socket 775″]
Socket LGA775 is the socket type currently used by Intel CPUs. If you have a socket LGA775 motherboard this means you have a Socket LGA775 Celeron D, a Socket LGA775 Pentium 4, a Socket LGA775 Pentium 4 Extreme Edition, a Pentium D, a Pentium Extreme Edition, a Core 2 Duo, a Core 2 Extreme or a Core 2 Quad. Keep in mind that some of these CPUs are available for other sockets as well, so we are talking specifically about socket LGA775 models here. In order to know what is the fastest CPU you can install on your motherboard, you will need to know what is the maximum FSB clock rate your motherboard supports. Typical values are 533 MHz, 800 MHz and 1,066 MHz.
To make things simpler, we compiled two tables, shown below. At one side you have your motherboard FSB and on the other which CPUs are supported.

FSB	Celeron D	Pentium 4	Pentium 4 Extreme Edition	Pentium D	Pentium Extreme Edition
533 MHz	All socket LGA775 models, available up to 3.2 GHz (“351” model).	All socket LGA775 models up to 2.66 GHz, and 2.80 GHz, 2.93 GHz and 3.06 GHz models. Be careful, as there is a 2.80 GHz version also available with an 800 MHz FSB.	Not supported.	So far only 2.66 GHz model (“805” model). *	Not supported.
800 MHz	All socket LGA775 models, available up to 3.2 GHz (“351” model).	All socket LGA775 models up to 2.80 GHz, except the 3.73 GHz model.	All socket LGA775 models up to 3.40 GHz.	All models, available up to 3.60 GHz (“960” model). *	So far only 3.20 GHz model (“840” model). *
1,066 MHz	All socket LGA775 models, available up to 3.2 GHz (“351” model).	All socket LGA775 models, available up to 2.80 GHz.	All socket LGA775 models, available up to 3.73 GHz.	All models, available up to 3.60 GHz (“960” model). *	All models, available up to 3.73 GHz (“965” model). *

* Older socket LGA775 motherboards do not support Pentium D, Pentium Extreme Edition, Core 2 Duo, Core 2 Extreme and Core 2 Quad CPUs. This happens because of the new power specs required by these CPUs

FSB	Core 2 Duo	Core 2 Extreme	Core 2 Quad
533 MHz	Not supported.	Not supported.	Not supported.
800 MHz	So far only 1.80 GHz model (“E4300” model).	Not supported.	Not supported.
1,066 MHz	All models, available up to 2.66 GHz (“E6700” model).	So far only two models are available, X6800, a dual-core running at 2.93 GHz and QX6700, a quad-core running at 2.66 GHz.	So far only 2.40 GHz model (“Q6600” model).