Underclocking to reduce TDP

[zaku26]

I have a biostar mobo MCP6PB M2+. it supports Phenom II x4 955 95w. the problem is it is phased out already. the only remaining is the black edition which is 125w. My question is, can you underclock or undervolt a Phenom II x4 955 Black Edition 125w in order for its TDP to become 95w? Also, it says in the biostar website in my mobo "It is recommended to use 95w CPU" does this mean I can use 125w CPUs in it? Thanks a lot.

for reference: http://www.biostar.com.tw/app/en/mb/content.php?S_ID=456

 

[beenthere]

You probably could under-volt/clock the 965 BE so it's peak TDP is 95w but it may not be worth it unless you can get the CPU real cheap. The 125w 965 BE is less efficient and that's why it requires a higher voltage than the 95w version.

 

[geekapproved]

Why not a Phenom II X4 840?

Check make sure your mobo supports it before buying.

 

[henydiah]

955 Be wil drop to x12 maybe ran at 2.4ghz ... And not stable. If you have this cpu get am3+ mobo and if you had this mobo re-sell and get Am3+ .
Time is upgrage next generation

 

[zaku26]

thanks for your inputs. the phenom IIx4 840 is not supported by my mobo, the 955 is the best supported cpu on my mobo. I really want to upgrade to am3+ but I don't have the money right now. I wish I could get it to work on my mobo.

 

[FALC0N]

You probably could under-volt/clock the 965 BE so it's peak TDP is 95w but it may not be worth it unless you can get the CPU real cheap. The 125w 965 BE is less efficient and that's why it requires a higher voltage than the 95w version.

Thats not true at all. Its rated at 125 watts because it has higher default voltage to facilitate overclocking.

You most certainly CAN undervolt the 965 to get it to 95 watts.

All you have to do is drop the voltage to 1.20v and it becomes a 95 watt part. It should work. Then stress test it to make sure it works under load at that voltage.

Alternatively, the x4 945 is still floating around at 3.0 ghz and 95 watts.

 

[FALC0N]

.......Also, it says in the biostar website in my mobo "It is recommended to use 95w CPU" does this mean I can use 125w CPUs in it? Thanks a lot.

for reference: http://www.biostar.com.tw/app/en/mb/content.php?S_ID=456

You can, abut I wouldn't recommend it. 95 watt boards don't have strong power regulation circuitry. It would likely work, but undervolting or using a native 95 watt part is the better choice.

 

[geekapproved]

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103809&nm_mc=EMC-IGNEFL082511&cm_mmc=EMC-IGNEFL082511-_-EMC-082511-Latest-_-ProcessorsDesktops-_-19103809-L03D

$95

 

[zaku26]

Thats not true at all. Its rated at 125 watts because it has higher default voltage to facilitate overclocking.

You most certainly CAN undervolt the 965 to get it to 95 watts.

All you have to do is drop the voltage to 1.20v and it becomes a 95 watt part. It should work. Then stress test it to make sure it works under load at that voltage.

Alternatively, the x4 945 is still floating around at 3.0 ghz and 95 watts.

okay I finally decided to undervolt a phenom II 955 BE, thanks!

p.s. I used this http://www.extreme.outervision.com/tools.jsp#cpuoc to estimate the wattage of an undervolted/underclocked Phenom II x4 955 and at 3ghz with 1.2v vcore its estimated wattage is 93w. Do you think it's somewhat accurate? and is cpu wattage same as tdp?

I hope this works, cheers

 

[FALC0N]

okay I finally decided to undervolt a phenom II 955 BE, thanks!

p.s. I used this http://www.extreme.outervision.com/tools.jsp#cpuoc to estimate the wattage of an undervolted/underclocked Phenom II x4 955 and at 3ghz with 1.2v vcore its estimated wattage is 93w. Do you think it's somewhat accurate? and is cpu wattage same as tdp?

I hope this works, cheers

Yes it is accurate. I used the same tool to come up with the 1.2v figure suggested earlier.

 

[zaku26]

Best answer selected by zaku26.

 

[geekapproved]

I fail to understand why you would buy a 955BE and underclock it when you can buy a 95w 945 for $95.......Makes zero sense.

 

[zaku26]

It is because the 945 95w is phased out here in my country. The 945 is what I was supposed to buy if only there was still some here. and unfortunately amazon,newegg, etc. doesn't ship here.

 

[FALC0N]

And if someday you move the chip to a better board, you have the unlocked multiplier to play with.

 

[Mousemonkey]

This topic has been closed by Mousemonkey