Cheapest (energywise) way to fold - 980Ti vs. 980Ti + 960

[2N5R]

Hello everybody,

lets assume two identical computers. One of them is equipped with a GTX 980 Ti, the other is equipped with a GTX 980 Ti and a GTX 960.
Both computers are folding on full power and are stopped upon reaching 10.000.000 Points. Which computer did consume less energy?

The 980 Ti only machine, I would suggest. Is that correct?

[foldy]

Right! (Except the computer with 2 GPUs got hotter and had to downclock the GPUs and CPUs and the remaining used power was less then one gpu computer with full speed power using and or got more PPD for the same amount of power.)

[2N5R]

Thank you!

[Ricky]

foldy,

I have 2 computers that have each have 2 GPUs that run full clock speed on all GPUs and CPUs.

[foldy]

Right! (The part in parantheses was just an theoretical idea against it)

This is how you calculate this:
The gtx 980ti gives 700k PPD for 280 watts. The added gtx 960 gives 180k PPD for 150 watts. And the PC alone will take 100 watts.

For gtx 980ti alone this is 700K PPD at 380 watts. 10 Mill PPD / 700k PPD * 380 watts = 5500 watts in 14 days
For gtx 980ti+gtx 960 this is 880K PPD at 530 watts. 10 Mill PPD / 880k PPD * 530 watts = 6022 watts in 11 days

So the result is close, only 10% difference in power usage and can vary depending on exact hardware.
Of course the dual GPUs are faster and get to 10 Mill PPD 3 days or 25% faster.

[Nathan_P]

Your maths is way off, first watts is measured by the hour, kwh on your leccy meter, and a 980ti would be very hard pushed to do 700k ppd, a more sensible metric would be 600k ppd.

10mill ppd/600k gives a run time of 16.67 days, at 380 watts per hour, that's .380*24*16.67= 152.03 kwh from the meter, at a rate of $0.10 per kwh that's going to cost $15.20
10mill ppd/780k gives a run time of 12.82 days, at 530 watts per hour, that's .530*24*12.82= 163.07 kwh from the meter, at a rate of $0.10 per kwh that's going to cost $16.31

[foldy]

You are right I missed the watts per hour but the relative comparison is still right.

There is a trick to reduce the power target for the GPU to e.g. 70% which will lead to reduced voltage and core clock but more efficiency.
https://www.reddit.com/r/Folding/commen ... om_100_to/

The 70% gtx 980ti will give 500k PPD for 200 watts plus 100 watts of PC = 300 watts
10 Mill PPD / 500k PPD gives a run time of 20 days at 300 watts per hour = .300*24*20 = 144 kwh from the meter, at a rate of $0.10 per kwh that's going to cost
$14.40

So it takes 3 days longer to fold 10 Mill PPD but another 10% power saved.

[bruce]

There's no such thing as"watts per hour"

Watts measures the continuous rate at which power is used.

The power costs is measured based on Watt-hours (or kwh) which is the total amount of energy used if it's consumed at a particular rate (watts) for a period of time (hours).

If the speed at which you tavel is measure in MHP (or KPH) [corresponding to Watts] and you maintian that speed for a period of time (hours) then the distance can be measure in MHP-hours and the fuel burned can be meausred in GPM-hours (or l/h-hours) which end up meaning gallons or liters.