# How to Calculate Overclocked Power Consumption

Discussion in 'Die-hard Overclocking & Case Modifications' started by G L, Jun 30, 2004.

1. ### pereraActive Member

Messages:
71
0
GPU:
x800gto 512mb 580/1200
but what about the fsb? overclocking it also changes the wattage?

and actually its a p4, and it is in the top of its series

i did the math on that power supply test, and i got 320 watts ..and im still with a generic agps400q of vcom... lol

she really does suffer, i already got 11.3 volts on 12+ with it

Last edited: Jul 27, 2005
2. ### G LDon Juan

Messages:
10,261
0
GPU:
Leadtek 8800 GTS 640 MB 600/1000
Well, guess I might as well give a newer example than the old beloved Athlon XP. Here's the Intel 6xx series datasheet:

If you go to page 76, you'll see that the TDP of the 3.8 GHz P4 670 is listed as 115 watts, and the vcore is rather confusingly specified as 1.2 to 1.4 volts on page 25, though of course if you own the processor in question you just use hardware monitoring to see what vcore you're running. I'll use what is apparently the worst-case scenario, 1.4v.

So let's say we OC to 4.2 GHz, which apparently is quite attainable with sufficient power and good cooling, and let's say that requires 1.6 volts. That gives us:

OC Wattage = TDP * (OC MHz / Stock MHz) * (OC Vcore / Stock Vcore)^2

OC Wattage = 115 * (4200 / 3800) * (1.6 / 1.4)^2

OC Wattage = 115 * (1.105) * (1.142)^2

OC Wattage = 115 * 1.105 * 1.304

OC Wattage = 165.7

For 166 watts, if you want both decent temps and barable noise you're going to want a fairly monstrous heatsink or spring for water-cooling.

3. ### G LDon Juan

Messages:
10,261
0
GPU:
Leadtek 8800 GTS 640 MB 600/1000
Most directly by changing the CPU speed... but changing the FSB will also overclock the chipset, which would presumbably also increase wattage. Though if you knew the chipset TDP and voltages, you could presumbably run the same equation for that. RAM is another one, but same deal. Though I don't think chipset and ram consume much more than 25 watts each stock. CPU and video card can both consume over 100 watts each, but after that I'd be suprised if the rest of the system combined topped 65 watts, assuming you're not running a DC pump or TEC module off your power supply, of course.

4. ### pereraActive Member

Messages:
71
0
GPU:
x800gto 512mb 580/1200
changin a bit the subject, i know that the recommended +- voltage is 5% , but im gettin somtimes 11.3 volts at 12+..is it that bad?

5. ### G LDon Juan

Messages:
10,261
0
GPU:
Leadtek 8800 GTS 640 MB 600/1000
Sounds pretty normal to me... I have a \$200 power supply, and I still only have 11.65v right now.

6. ### pereraActive Member

Messages:
71
0
GPU:
x800gto 512mb 580/1200
im gettin a seventeam 420 bkv next month..prolly also vantec tornado, if i like it 2 of them... im also buyin the fan controler a2140 for thermaltake..hes at least meant to take the tornados

7. ### GamuMember

Messages:
15
0
GPU:
MSI 6800GT @ Ultra (ItWill be Leadtek 7800GTX)
Is this a Real A64 Model Number?:

LBBLE 0516MPM
4424684F51654

Because, it's only 3 letters in the end of the 2nd line...

PLs. Hurry, I need this!

8. ### G LDon Juan

Messages:
10,261
0
GPU:
Leadtek 8800 GTS 640 MB 600/1000
Repost this somplace else, please, this thread is for something else entirely.

9. ### redtzm_96Member

Messages:
40
0
GPU:
erh.. here a dummy Q from me.. what is the tdp..? eheh

10. ### G LDon Juan

Messages:
10,261
0
GPU:
Leadtek 8800 GTS 640 MB 600/1000
Thermal design power, basically power consumption/heat dissipation at load. So if you read a review that says a P4 3.8 GHz can dissipate up to 115 watts, that's its TDP. No way to reason it in the abstract, so you have to check the manufacturer's specs for that. I've seen TDP used interchangably to indicate both power consumption and heat dissipation, so apparently all power consumption is converted into heat.

11. ### KainAncient Guru

Messages:
3,857
0
Very nice information.
I have never seen this thread.

Now, i know if i can OC a lot my processor.

G L. Here is a question.

I have the PSU in my Specs.

Now, im upgrading to socket 939 and PCI-E.

Im bought an Opteron 146 CABYE 0540 which im panning to OC to 3.0 ghz or soo
Also i will be using an DFI SLI Infinity mobo
And finally i will be getting a 6800GS the next week.

So, the specs for my system will be the same except for the above mentioned.

I used the very usefull link you gave to calculate the wattaga and it scored about 30 to 340 watts (depending on how you said to double the DDR wattage).

My PSU should be enough to handle this system right?
In that case, i have about 80 watts leaving which should be used for the OC consumption, right?

Is this safety? Or, should i buy another PSU before OCing?

Also, this PSU shows it supports a maximum peak of 500 watts.

12. ### r00723r0New Member

Messages:
9
0
GPU:
XFX GeForce 6800GS XXXe 256MB
Wow, uhh... It's basic algebra... You might as well learn algebra before overclocking

In any case, I know that a 33% increase is about tops for voltage, but what about wattage? Does it depend on the dissipation power of the cooler?

13. ### ShamilMember

Messages:
43
0
GPU:
eVGA 6600GT 128mb AGP w/VF700cu
I have calculated that overclocking my P4 from 3ghz to 3.4ghz will require 102 watts @ peak... Good equation, thank you.

Only problem is I have no idea what the TOTAL power requirements will be on my PSU, and this thread has not helped me determine that at all.

I am using 2x 80mm fans in the front, 1x 80mm fan in the back, 1x 80mm on top (all Vantec Stealths, top fan is a Panaflo). I have another 80mm 2700rpm on top of the CPU.

I am using a 6600GT 128mb AGP overclocked to 570/1060 (no volt mods: AGP slot default @ 1.55v)

4x512mb of DDR400 RAM over-volted to 2.7v

I have a Sound Blaster Audigy 2 which is soft-modded into an Audigy 4.

And I have a USR wireless network PCI card @ 125mbps.

I also have 1x Seagate 120gb SATA and 1x Western Digital 250gb.

Is there ANY way to determine if this will cause problems for my 420 watt Enermax Noisetaker??

14. ### Dublin_GunnerAncient Guru

Messages:
4,642
0
GPU:
Gigabyte Rx 460 4GB

Messages:
2,889