How much can I overclock a 95watt cpu on a 95watt MOTHERBOARD? HELP?

Toggle sidebar Toggle sidebar
K

kebbz

Honorable
Jul 27, 2012
212
0
10,680
Hey guys I really want to get some extra juice out of this cpu.

I got an athlon x3 455 3.3ghz. How much can I push it without damaging the board?
 
Sort by date Sort by votes
Maxx_Power

Maxx_Power

Distinguished
Jul 17, 2012
1,861
0
20,160
If you lower the Vcore and increase the base clock a bit, you can get a couple hundred megahertz before anything goes wrong, because the power consumption increase caused by the higher frequency is offset by the decrease in the Vcore. But doing it this way, you will really only have a few hundred Mhz of OC head-room, tops.

Either way, you won't be able to get more than a few hundred Mhz if your motherboard was only designed to take a 95W CPU.
 
Upvote 0 Downvote
Jonathan Sifleet

Jonathan Sifleet

Honorable
Apr 25, 2013
926
0
11,160


TDP on the CPU and MOBO make no effect whatsoever. It's about your Vcore and your cooling solution that you need to worry about.
 
Upvote 0 Downvote
K

kebbz

Honorable
Jul 27, 2012
212
0
10,680


So if i push it to 4ghz i do not need to worry about blowing up my motherboard? Please answer!
I have tested it to 3.6ghz and it booted up fine. But didnt risk taking stability test.
 
Upvote 0 Downvote
Maxx_Power

Maxx_Power

Distinguished
Jul 17, 2012
1,861
0
20,160


His motherboard (likely) only has a VRM system rated for 95 Watts max TDP CPU. A lot of lower end motherboards and brand name boxes do this to cut costs, all of those boards specifically state that the max TDP CPU you can put into those boards is 95 Watts. A while ago there was an OP here on Toms who had a lot of issues trying to run a FX8000 (125Watt TDP) series chip on a motherboard with a 95 Watts max VRM section, he had a lot of throttle and instability issues with that FX8000 chip, not the 95 Watt TDP Phenom II he had before.

When you overclock, the amount of current going through the chip is proportional to the frequency. So the power supplied is proportional to the first power of frequency (and junction capacitance...), and as usual, the 2nd power of voltage (Vcore). Which is why I mentioned that for a fixed power (in his case 95 Watts), if he lower the Vcore, he'll get more frequency in compensation, up to that chip's stability margin, which is usually over-rated a bit, hence the little headroom (couple hundred Mhz).

See this quick wiki for CPU power dissipation as a function of voltage and frequency:

http://en.wikipedia.org/wiki/CPU_power_dissipation

Essentially, P=CV^2 f, where C is total effective junction capacitance, V is typically Vcore and f is frequency. Choose Si units everywhere and you get P in watts.
 
Upvote 0 Downvote
Jonathan Sifleet

Jonathan Sifleet

Honorable
Apr 25, 2013
926
0
11,160


Well, you dont want to ramp up your Vcore to x.x if it only needs to be y.y
 
Upvote 0 Downvote
Maxx_Power

Maxx_Power

Distinguished
Jul 17, 2012
1,861
0
20,160


Please take a look at this information database for your motherboard model and see if the VRM has been deemed "strong" enough for OCing. We don't know what your model is....
http://www.overclock.net/t/946407/amd-motherboards-vrm-info-database
 
Upvote 0 Downvote
K

kebbz

Honorable
Jul 27, 2012
212
0
10,680






My mother board is an Asrock N68-VS3 FX. I see some of its previous versions listed there. So I assume it's a 3 phase.
Also, i do not have Vcore setting in the bios. I only can change the cpu Voltage. The vcore is greyed out.
 
Upvote 0 Downvote
E

ethereal essence

Honorable
Jun 5, 2013
753
0
11,360


Honestly, if you are that concerned about frying your motherboard, do NOT risk overclocking. Under the best of circumstances, overclocking still carries some risks. Since your cpu's TDP is already at the max supported by your board, you don't have any room to work with. The best you could do, as suggested before, is to lower your voltage just a bit and try for a 100-200 mhz overclock.

Honestly it wouldn't be worth the effort and you'd probably have a hard time getting it stable. It would still be a risk since if you didn't lower the voltage enough, you could fry your motherboard. Honestly is 200 mhz really worth ruining your PC and requiring you to replace it or go without one?
 
Upvote 0 Downvote
Maxx_Power

Maxx_Power

Distinguished
Jul 17, 2012
1,861
0
20,160


Does your board look like this ?
n68-vs3-fx-32207.jpg


If so, it is definitely a 3-phase VRM with a 2 transistor forward design (probably one of the worst for overclocking).

You can try to increase the clocks by a very little bit, say 100 to 200 mhz without messing with the voltages. I am not sure what the CPU voltage you refer to means, typically it is the same as Vcore (or core voltage). On the AMD AM3 systems, you'll have a separate voltage for the IMC+Cache and the actual cores. You can probably also get a bit more performance by lowering the ratio, but raise the bus speed. The idea is to speed up the IMC and thus getting better performance by keeping the cores better fed. You can usually get 10% more clock out of this by increasing the bus speed 10% (say, 220 Mhz instead of 200 Mhz), and drop the ratio of the CPU (multiplier) one notch or half a notch to compensate. Your RAM clocks will go up as well, so if you don't have 1600 Mhz RAM, this is usually moot...
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom