# Will an AM3 CPU work in a AM2+ Motherboard?



## Nick89 (Oct 27, 2011)

I'm trying to upgrade my friends computer for him. I found a Phenom II X4 955 black edition for 110$ and he has a decent AM2+ mother board. His current processor is an Athlon X2 5600+ 2.8 Ghz. So the performance increase would be great. 

I tried to find PII 920's and 940's but they are scarce.

His current setup:

Athlon 64 X2 5600+
2 GB ram
XFX 4870 1GB

We are trying to upgrade to:

Phenom II 920/940/955
4 GB ram
6870 1GB


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## erocker (Oct 27, 2011)

Whatever motherboard it is, I'm quite sure it has a CPU support page on its website. Look it up.


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## sneekypeet (Oct 27, 2011)

erocker said:


> Whatever motherboard it is, I'm quite sure it has a CPU support page on its website. Look it up.



just cause you told me to
http://www.gigabyte.com/support-downloads/cpu-support-popup.aspx?pid=3032


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## erocker (Oct 27, 2011)

sneekypeet said:


> just cause you told me to
> http://www.gigabyte.com/support-downloads/cpu-support-popup.aspx?pid=3032



I'm not sure if that's the motherboard his friend has though.


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## sneekypeet (Oct 27, 2011)

see what I get for trying to help????


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## Frick (Oct 27, 2011)

Aye, just do what erocker tells you to.


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## Super XP (Oct 28, 2011)

Here's a quote from 2009:


> Today AMD is releasing two new processors, the Phenom II X4 955 and 945, which are based on the same “Deneb” architecture though with a few notable changes. The most prominent change is that these are AM3 processors, and therefore *can be used with either DDR2 or DDR3 memory*. AM3 processors are also completely backwards compatible with AM2+ motherboards.


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## Nick89 (Oct 28, 2011)

Thank you Erocker, Sneeky, and Super XP. You guys rock!


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## Thefumigator (Oct 28, 2011)

Nick89 said:


> Thank you Erocker, Sneeky, and Super XP. You guys rock!



just be careful with wattage. the PII 955 is rated at 125watts I think. Well it depends, just google its code.

My motherboard is an ECS GF8200 and despite being AM2+, only 95watts processors are supported. Which means that if I want 6 cores, only the Phenom II X6 1035 will run without making my mobo explode.


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## xBruce88x (Oct 28, 2011)

my board is an AM2+ and it works just fine with a Phenom II X4


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## hat (Oct 28, 2011)

I use an AM3 processor (Phenom II 550) in my AM2+ board (Biostar TF720 A2+) without issue. The difference between AM2+ and AM3 is whether you are using DDR2 (AM2+) or DDR3 (AM3). Just be sure the board can handle the power draw of the CPU.


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## Jetster (Oct 28, 2011)

So Im not an AMD guy but I have to ask; if they work in a AM2 socket whats the benifit of buying a AM3 board?


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## Red_Machine (Oct 28, 2011)

My old AM2+ mobo supported AM3 CPUs, but only if it had a TDP of less than 95w.  You'll want to keep that in mind in case your board has that limitation.


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## xBruce88x (Oct 28, 2011)

Jetster said:


> So Im not an AMD guy but I have to ask; if they work in a AM2 socket whats the benifit of buying a AM3 board?



the am3 boards usually have better IGPs and southbridge chips that AM2 cpu's couldn't work with, however the AM3 cpu's were able to work with the AM2 and AM3 platforms as far as chipsets, but AM2 cpu's couldn't do some of the features of the newer chipsets for AM3, and something about memory. (i think am3 introduced DDR3 with amd, while AM2 was ddr2)

Power draw is usually the biggest concern with using an AM3 cpu on an AM2 board i think.


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## Frick (Oct 28, 2011)

xBruce88x said:


> Power draw is usually the biggest concern with using an AM3 cpu on an AM2 board i think.



Only if you go for the high end CPUs.

This information can normally be found at the motherboards homepage.


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## Derek12 (Oct 28, 2011)

Maybe you will need to update your BIOS if you didn't. My board needed to update it to the latest to accept most AM3 CPUs.


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## Thefumigator (Oct 28, 2011)

Jetster said:


> So Im not an AMD guy but I have to ask; if they work in a AM2 socket whats the benifit of buying a AM3 board?



you don't know what you are missing  

AM3 was released in 2009, just for supporting DDR3 memory. Which is cheaper than DDR2, as far as I take a look at some price list information

AM3 also supports turbo, allowing overclock of each core individually. And supports better Hyper Transport.

Moreover:
AM3 processors work on AM2+ motherboards due to the presence of both the DDR2 and DDR3 memory controllers on the processor.

AM2+ processors do not work on AM3 motherboards due to the processor's lack of a DDR3 memory controller.

There's an exception here, Asrock released not long ago an AM3 motherboard supporting AM2+ processors, featuring both DDR2 and DDR3 slots, and it works really good despite the chipset chosen (nforce 600 with geforce 7000 series IGP). Its the only board I know that features bidirectional compatibility. The only restriction is that if you are going to put an AM2 processor in this board, only DDR2 will work. But the slots are present. Poping in an AM3 cpu will work with both DDR2 or DDR3 memory. 

On the other side, you will find "AM3 ready" motherboards, which are not the same as "AM3" motherboard, since "AM3 ready" refers to those AM2/AM2+ boards that support AM3 cpus.


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## cheesy999 (Oct 28, 2011)

Thefumigator said:


> There's an exception here, Asrock released not long ago an AM3 motherboard supporting AM2  processors, featuring both DDR2 and DDR3 slots, and it works really good despite the chipset chosen (nforce 600 with geforce 7000 series IGP). Its the only board I know that features bidirectional compatibility. The only restriction is that if you are going to put an AM2 processor in this board, only DDR2 will work. But the slots are present. Poping in an AM3 cpu will work with both DDR2 or DDR3 memory.



i have that board, and it does in fact, work really well, it's supposed to be limited to 95W proccesors, but i'm running a phenom x4 at 3.5GHZ with no problems


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## m4gicfour (Oct 28, 2011)

cheesy999 said:


> i have that board, and it does in fact, work really well, it's supposed to be limited to 95W proccesors, but i'm running a phenom x4 at 3.5GHZ with no problems



Yeah most boards can handle processors which are out of spec for wattage as long as they aren't overclocked too much, you just run the risk of burning out the VRMs and potentially taking the CPU with it


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## Thefumigator (Oct 28, 2011)

m4gicfour said:


> Yeah most boards can handle processors which are out of spec for wattage as long as they aren't overclocked too much, you just run the risk of burning out the VRMs and potentially taking the CPU with it



Exactly, also shortening mobo life.
There are some X4 that are 95watts, maybe his?


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## Nick89 (Oct 28, 2011)

Thefumigator said:


> just be careful with wattage. the PII 955 is rated at 125watts I think. Well it depends, just google its code.
> 
> My motherboard is an ECS GF8200 and despite being AM2+, only 95watts processors are supported. Which means that if I want 6 cores, only the Phenom II X6 1035 will run without making my mobo explode.



The Mother board is a Jetway HA07-Ultra, it has 140w CPU support. And I just noticed it has "AM3 Ready" on the box.


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## Thefumigator (Oct 28, 2011)

Nick89 said:


> The Mother board is a Jetway HA07-Ultra, it has 140w CPU support. And I just noticed it has "AM3 Ready" on the box.



Ha! with that SB it will unlock Phenom II X2/X3 to X4 and sempron 140 to X2, with a little bit of luck. Its a very nice motherboard. indeed.


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## Frick (Oct 28, 2011)

Thefumigator said:


> Ha! with that SB it will unlock Phenom II X2/X3 to X4 and sempron 140 to X2, with a little bit of luck. Its a very nice motherboard. indeed.



Also Athlon X3's to X4 or Phenoms.


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