Is my 300W PSU Enough?

[gvx64]

I had thought a few months ago (when I did this build) that my 300W PSU would be sufficient, however, I have been reading some recent posts on this board about newer GPU's causing power spikes (eg. this thread: https://hardforum.com/threads/will-my-old-psu-be-enough-for-this-build.2024161/) and so I am becoming a bit more concerned about the adequacy of my existing PSU.

I had originally used the Shuttle PSU calculator to determine my system's expected power consumption and this is what I came up with:
https://global.shuttle.com/support/power?productId=2344

BTW, note that I have a GTX 1650 Super (not available on the dropdown) which has a TDP that is 20W lower than the 1060 and so the total usage for my system should theoretically be 262W not 282W shown above. I figured that being below 90% rated capacity should be enough safety factor but I would like to get your thoughts here.

Note also that I am using a CyberPower UPS with sinewave power output. It obviously won't save the PSU from power spikes from hardware in the PC but my thoughts are that it should reduce the risk to the PSU of utility-side voltage spikes.

If there are concerns with the 300W PSU, I can upgrade to a 500W Shuttle PSU. It's a bit pricey, however, it is on my long-term radar of planned upgrades regardless so that I can eventually get a better GPU. That said, if there are risks of overloading this PSU with my existing components, then I will prioritize getting the PSU upgrade done sooner rather than later.

Thanks a lot.

 

[Phazer Tech]

It might be okay but the only way to be sure is to test it yourself and hook up a watt meter to see how much power its drawing. Run a CPU and GPU stress test simultaneously and if it shuts down then you know its not enough. If it stays on then the watt meter will tell you how much headroom you have.

 

[Phazer Tech]

Another thing, undervolting the CPU and/or GPU might help a lot in cases like this. Also reducing the power limit for the GPU in MSI afterburner is easier than undervolting it.

 

[gvx64]

It might be okay but the only way to be sure is to test it yourself and hook up a watt meter to see how much power its drawing. Run a CPU and GPU stress test simultaneously and if it shuts down then you know its not enough. If it stays on then the watt meter will tell you how much headroom you have.

Thanks a lot for that suggestion, I didn't think of measuring actual usage (duh).

So, I turned everything off that was connected to my UPS except for my PC, the monitor and an idling raspberry Pi that I didn't want to disconnect and then ran Heaven Benchmark 4.0 (gpu benchmark). The total power consumption on my UPS averaged around 160-170W with occaisonal spikes up to close to 200W. From what I could tell, it never went over 200W. That being said, I don't think that there was multicore CPU utilization in the benchmark that I used and so these values may not be the true max load during full multi-core CPU+GPU load. That benchmark is from 2009 and so I will see if there is anything more recent that I don't have to pay money for.

 

[Phazer Tech]

Thanks a lot for that suggestion, I didn't think of measuring actual usage (duh).

So, I turned everything off that was connected to my UPS except for my PC, the monitor and an idling raspberry Pi that I didn't want to disconnect and then ran Heaven Benchmark 4.0 (gpu benchmark). The total power consumption on my UPS averaged around 160-170W with occaisonal spikes up to close to 200W. From what I could tell, it never went over 200W. That being said, I don't think that there was multicore CPU utilization in the benchmark that I used and so these values may not be the true max load during full multi-core CPU+GPU load. That benchmark is from 2009 and so I will see if there is anything more recent that I don't have to pay money for.

That's correct, the CPU wasn't being fully utilized. You can run Prime95 small FFT while running Heaven to find the max load.

 

[Dreamerbydesign]

I had thought a few months ago (when I did this build) that my 300W PSU would be sufficient, however, I have been reading some recent posts on this board about newer GPU's causing power spikes (eg. this thread: https://hardforum.com/threads/will-my-old-psu-be-enough-for-this-build.2024161/) and so I am becoming a bit more concerned about the adequacy of my existing PSU.

I had originally used the Shuttle PSU calculator to determine my system's expected power consumption and this is what I came up with:
https://global.shuttle.com/support/power?productId=2344
View attachment 535027
BTW, note that I have a GTX 1650 Super (not available on the dropdown) which has a TDP that is 20W lower than the 1060 and so the total usage for my system should theoretically be 262W not 282W shown above. I figured that being below 90% rated capacity should be enough safety factor but I would like to get your thoughts here.

Note also that I am using a CyberPower UPS with sinewave power output. It obviously won't save the PSU from power spikes from hardware in the PC but my thoughts are that it should reduce the risk to the PSU of utility-side voltage spikes.

If there are concerns with the 300W PSU, I can upgrade to a 500W Shuttle PSU. It's a bit pricey, however, it is on my long-term radar of planned upgrades regardless so that I can eventually get a better GPU. That said, if there are risks of overloading this PSU with my existing components, then I will prioritize getting the PSU upgrade done sooner rather than later.

Thanks a lot.

Just chiming in to say the UPS will not regulate the power spike from the utility side as you may think. A power conditioner may work though. The UPS doesnt do too much filtering between the mains voltage and the outputs to the pc, For instance, chances are that UPS does not add voltage during a voltage dip utility side. You may think it would, but they do not unless you have a fancy high end enterprise UPS setup. They are rather limited in filtering. Mainly they are used for what they say. As a battery backup to keep things running during a power outage or a momentary power drop.

 

[gvx64]

That's correct, the CPU wasn't being fully utilized. You can run Prime95 small FFT while running Heaven to find the max load.

OK, I used a 12 thread cpu stress test in CPU-Z and then initiated Heaven at the same time and then looked at the power consumption on my UPS. For the first 5 seconds or so the power consumption shot up to around 280-285W but then came down and settled at around 200-210W and stayed there after for the remainder of the test. I looked into what was going on using the Intel Extreme Tuning Utility and it looks like the CPU briefly goes up to 128-129W TDP at the beginning of the stress test but then after a few seconds at that level, power throttling initializes and brings the TDP down to 65W (65W is the advertised power consumption of the i5-11400f, I have no idea why it's being allowed to draw >125W for a while, I am not overclocking anything).

Yeah, so I guess that the 285W is a bit concerning for me, it's very close to the 300W limit of the PSU even if it is just for a few seconds. It is certainly a lot closer than what Shuttle's PSU calculator indicated. I am not sure, maybe I should plan a PSU upgrade sooner rather than later. Alternatively, maybe there is a way that I can cap the i5-11400F at 65W maximum and not let it draw double it's rated TDP for the few seconds that it does.

Just chiming in to say the UPS will not regulate the power spike from the utility side as you may think. A power conditioner may work though. The UPS doesnt do too much filtering between the mains voltage and the outputs to the pc, For instance, chances are that UPS does not add voltage during a voltage dip utility side. You may think it would, but they do not unless you have a fancy high end enterprise UPS setup. They are rather limited in filtering. Mainly they are used for what they say. As a battery backup to keep things running during a power outage or a momentary power drop.

Thanks for the information. I wish that I had spoken to somebody like you before I made the purchase. That is a bit disappointing to hear as the product advertises itself that it "corrects for minor power fluctuations to protect your valued electronics":

https://www.bestbuy.ca/en-ca/produc...Dd1KbEG5Irq6qg_YTaxoC1igQAvD_BwE&gclsrc=aw.ds

I mainly got it because I live in a rural area where there are lots of outages and blips in the power. I wanted something that is a bit better than a surge protector, however, I probably should have done more research into the details before buying. The battery backup is nice to have so I guess if that's all it does it still has some value.

 

[gvx64]

Hey, I apologize for the double post but I found this option in the Intel Extreme Tuning Utility. Reducing this value down to 65W seems to fix the problem!

 

[deaedius]

That is during stress testing, that is an extreme situation that you wont encounter very often. I would say your system will hover around 175 to 220 watt range. Unless you sit and play with benchmarks all the time then you should have nothing to worry about.

 

[Phazer Tech]

Hey, I apologize for the double post but I found this option in the Intel Extreme Tuning Utility. Reducing this value down to 65W seems to fix the problem!


View attachment 535519

Yep that looks like the setting you want!

 

[chameleoneel]

Hey, I apologize for the double post but I found this option in the Intel Extreme Tuning Utility. Reducing this value down to 65W seems to fix the problem!


View attachment 535519

That's the normal turbo power usage. If your CPU is under full load, it will turbo at up to 150 watts, for about 60 seconds. Then it will restrict itself to 65w after that, if the full load remains constant.

In gaming, your CPU will basically never sustain a full load. You will never see a constant 150w of CPU usage, while gaming. Limiting your turbo to 65w could hurt your gaming performance, in certain situations.
But, it shouldn't be too noticeable, for that CPU. As 65w should be enough to turbo 1 or 2 threads at their max speed, for most gaming loads. However, there may be situations where more threads are needed and your CPU could temporarily burst to say---120watts, to power the turbo for a few threads. Those situations will suffer.

300w power supply is fine for your system

 

[gvx64]

That's the normal turbo power usage. If your CPU is under full load, it will turbo at up to 150 watts, for about 60 seconds. Then it will restrict itself to 65w after that, if the full load remains constant.

In gaming, your CPU will basically never sustain a full load. You will never see a constant 150w of CPU usage, while gaming. Limiting your turbo to 65w could hurt your gaming performance, in certain situations.
But, it shouldn't be too noticeable, for that CPU. As 65w should be enough to turbo 1 or 2 threads at their max speed, for most gaming loads. However, there may be situations where more threads are needed and your CPU could temporarily burst to say---120watts, to power the turbo for a few threads. Those situations will suffer.

300w power supply is fine for your system

Thanks for this info. What would you recommend setting this value to given my 300W PSU? Would you allow the full ~130W to be drawn (my cpu never seems to hit 150W even though the setting was there) or maybe set it a bit lower to 120 or 110W? Thanks again.

 

[chameleoneel]

Thanks for this info. What would you recommend setting this value to given my 300W PSU? Would you allow the full ~130W to be drawn (my cpu never seems to hit 150W even though the setting was there) or maybe set it a bit lower to 120 or 110W? Thanks again.

I would just leave it at stock Intel settings.

I don't think you will have power issues. But, you can always limit the power, if your power supply starts to get loud or something. Or if your SFF cooling gets too loud. Generally, Intel CPUs scale pretty well in gaming, down to about 100 watts. Under that is when they start having larger performance loss.

 

[Axman]

Yeah, so I guess that the 285W is a bit concerning for me, it's very close to the 300W limit of the PSU even if it is just for a few seconds.

Bear in mind, if that's power from wall (like, are you using a Kill-a-Watt?) then 285 includes the lost efficiency by the PSU. A 90 percent efficient PSU delivering 300 watts will consume 330 watts. So you might not be that close to your ceiling, although if you add enough USB devices...

 

[gvx64]

Bear in mind, if that's power from wall (like, are you using a Kill-a-Watt?) then 285 includes the lost efficiency by the PSU. A 90 percent efficient PSU delivering 300 watts will consume 330 watts. So you might not be that close to your ceiling, although if you add enough USB devices...

OK, that's a really good point. So the 300W rating of the PSU is the amount of DC power output from it to the computer components, not what is being drawn from the UPS? Yes, my PSU is a 300 Bronze meaning that it is 82% efficient under full load and so you would be absolutely right, what is drawn by the PSU (and displayed in kW on the UPS display) could even be 50W higher than what is actually delivered to the computer components.

Thanks again for bringing that point up.