WIll Corsair RM650X PSU Be Enough For 1080SLI

ZeeD · Dec 9, 2016

Hi,

The title pretty much says it. I had a GTX 1080 on Rm650x PSU, then I purchased another 1080 for sli. Both my 1080 are Zotac AMP Extreme. WIll the 650 psu be enough because I have had this system for 2 weeks doesn't seem to be a problem and I leave everything to factory overclock. I also run i7 6800k, aio cpu watercooler, 6 fans which are connnected via my fan controller through molex, an SSD, 2 and 4 tb hdd and 32gb of ram. I don't seem to be having any problems I can game perfectly and render videos fast.

Is there something im missing because im not a really techinical person when it comes to it, or is it totally fine for now?

thanks

turkey3_scratch · Dec 9, 2016

An RM550x would be fine for two.

bignastyid · Dec 9, 2016

650w is pushing it imho. Personally I'd run atleast a 750w unit.
http://www.guru3d.com/articles_pages/geforce_gtx_1080_2_way_sli_review,4.html

turkey3_scratch · Dec 9, 2016

bignastyid :

Your own link is contrary to your statement. 362W for two cards, not a big deal at all, especially on an RM550x or RM650x which should last 10 years running at 100% load 24/7 under 50C ambient temps.

ZeeD · Dec 9, 2016

Is there a way to monitor how many watts my system is taking?

bignastyid · Dec 9, 2016

turkey3_scratch :

It was an opinion(what the o in imho stands for). Never said it wouldn't work simple said I would run a 750w PSU with such a high end setup. I(and many others) prefer to run at 50-80% capacity as this is where they usually run quiet and most efficient. Even with a very good PSU I would never suggest someone runs it close or at 100% for extended periods of time.

bignastyid · Dec 9, 2016

ZeeD :

The RMx doesn't support corsair link, but you could use a kill-a-watt to measure power consumption from the outlet then factor an estimated 87-90% for the gold efficiency rating and that will give you a decent idea of how much the PSU is outputting.

logainofhades · Dec 9, 2016

turkey3_scratch :

That was just for the cards though. Add in an overclocked broadwell-E CPU, that is 140w TDP at stock, then those low wattage units are not going to cut it.

turkey3_scratch · Dec 9, 2016

logainofhades :

When you're gaming, the CPU is not fully utilized. What is the I5-6600K TDP, 91W? Let's take a look at how much power that uses when gaming.

http://www.tomshardware.com/reviews/skylake-intel-core-i7-6700k-core-i5-6600k,4252-11.html

51W. That is about 60% of the TDP. Of course it depends on the particular game, but the CPU is not going to be fully utilized always. Even if whatever CPU was doing 140W, who cares? It still doesn't really matter, still will be perfectly fine.

Onus · Dec 9, 2016

364W for the two cards, probably at least another 150W for the rest of the system (assuming a load); that's 514W. That's almost 80% of a 650W PSU, so should be okay. I would not use anything smaller; it might work, even safely, but considering spikes that have been measured which exceed TDP ratings, you'll be banging on it pretty constantly, which will likely reduce component lifespan.

turkey3_scratch · Dec 9, 2016

Onus :

Those PSUs are so underrated anyway. The RM550x should handle ~700W fine. The RM650x handles 807W continuous fine http://www.tomshardware.com/reviews/corsair-rm650x-psu,4611-6.html

The truth is, when you go from an RM550x to Rm750x, you're getting very little difference. They're almost identical, just some more filtering capacitors, stronger bridge rectifier, etc. in the end, the RM550x should handle heavy loads just fine.

If anything, the RM650x running at 80% load could last longer than the RM850x running at 50% load. This is because the RM650x fan will be spinning faster under the same load, keeping the capacitors cooler, whereas in the RM850x the capacitors might not live as long under the same exact system.

Though I don't know for sure. And neither can anyone.

TechyInAZ · Dec 9, 2016

turkey3_scratch :

Even if this is true, why risk it? I'd MUCH MUCH rather get a overkill PSU than risk buying a PSU and running it over it's specifications, just to save a few dollars.

Plus, there are also cases where both CPU and GPUs are fully utilized, like in F@H or mining or video rendering etc etc. When your buying a PSU, you have to make sure your getting enough power as if you were going to run every component at 100%, because that could very well happen at least a few times per the computers life.

turkey3_scratch · Dec 9, 2016

TechyInAZ :

turkey3_scratch :

Even if this is true, why risk it? I'd MUCH MUCH rather get a overkill PSU than risk buying a PSU and running it over it's specifications, just to save a few dollars.

Plus, there are also cases where both CPU and GPUs are fully utilized, like in F@H or mining or video rendering etc etc. When your buying a PSU, you have to make sure your getting enough power as if you were going to run every component at 100%, because that could very well happen at least a few times per the computers life.

You know how the saying goes, always getting a higher quality PSU is better than getting a higher wattage PSU. The RMx are some of those really high quality PSUs.

Onus · Dec 9, 2016

The OP asked a simple question; is a [specific] 650W PSU sufficient for [a specific load]? The answer is "Yes, it is."

On the subject of smaller different PSUs...

turkey3_scratch :

Exactly, which is why, particularly for the sake of people in similar situations looking for guidance, suggesting alternate parameters just muddies the water.

turkey3_scratch · Dec 9, 2016

Onus :

I wasn't the one muddying the waters, my initial response to the OP was crisp and concise. The water got muddied elsewhere so then I had to dive in.

logainofhades · Dec 9, 2016

But it makes more sense to get both the higher wattage, and the higher quality. Especially when you can get the higher wattage version for less, or for less than $20 more. The RMX750w is selling for $10 less than the 650, and the 850 is selling for $10 more than the 650w right now. Just because it "might/should" be good enough, doesn't mean you should do it. I have seen you often ask why, on a higher wattage PSU, ignoring the minor price difference. I'd rather spend that extra $10 and not worry about it.

The OP may be safe, as they are, but it would be something I would be concerned about, long term. My seasonic 650w was one of those good enough units, and it didn't hold up, to my system.

Onus · Dec 9, 2016

No, your initial response mentioned a different PSU. Keep in mind that in some cases, PSUs from the same line but of different wattages may use a different project and be of differing quality.
In any case, the OP's question has been answered. Let's move on please.

turkey3_scratch · Dec 9, 2016

logainofhades :

Ya but you can also save $10 and not worry about it, too. Nobody needs to be worried. It all just seems like too much FUD for me.

Onus :

Yes, I used it to make a point. And the RM550x is the same platform as the 650x.

Onus · Dec 9, 2016

turkey3_scratch :

In this case, they are; in the general case, they may not be.
T i m e t o m o v e o n.

4745454b · Dec 9, 2016

Who cares if it's the same platform? The OCP would be set to limit it to a "550W" PSU. No manufacturer I know sells the 550W with the OCP set at the same limit as the 750W. They wouldn't make any money once news of this got out because everyone would just buy the 550W model. Yes, review sites might test the OCP and find it set sky high, but how do you know the manufacturer didn't send them a "cherry" sample?

The RM550x should handle ~700W fine.

The "extra"/unlisted power provided by the higher OCP point shouldn't be "planned use" power. Meaning you shouldn't see 700W until the OCP kicks in and plan on using that full 700W. It doesn't allow for surges or anything like that. Going flat out to the max on your PSU is a bad idea. Period. As mentioned above, 50-80% of the RATED PSU output is where you should be targeting. Not only is it most efficient at that load, but it also won't fry your system if a spike in power usage is needed. For example.

http://www.tomshardware.com/reviews/nvidia-geforce-gtx-1080-pascal,4572-10.html

Spikes above 300W are a thing of the past. Nvidia’s GeForce GTX 1080 barely has any

Meaning that while it's a 180W card, if you check the power draw at a small enough interval there are times where it draws more. It seems it can spike as high as 300W+. What happens if you have a 550W PSU and both of your 1080s spike up to 300W each? How long do you think your PSU lasts then?

An RM550x would be fine for two.

Did you see where the OP said he's using two Zotac AMP Extremes? Those are dual 8pin cards, so four 8pin PCIe plugs are needed. How many plugs does your RM550x have? Looking at that PSU on newegg it seems you are a few plugs short.

I don't mean to pick on the RM550x at all. It's a good PSU. But I wouldn't pair it with those GPUs. It simply isn't a good idea. Some 650s can handle it, but a 750W would be best, more so if you plan on doing any OCing. You said you didn't understand why it works and it's because you have one of those 650s that I would consider safe. If you want to OC anything I'd bump up to a bigger PSU seeing as you'll need the extra power. But it works because you have a good 650W.

ZeeD · Dec 9, 2016

I'd like to thanks everyone that replied to this post now that I have an insight to power supplies. My 650 psu is doing fine for the time being, I don't do any manual OC so I should be okay. I want to upgrade my ram and hard drives first then hopefully when 1080ti comes out i want to build another system. Everyone is saying 650 is okay for now, I will probably upgrade it later on next year at some point

4745454b · Dec 9, 2016

Instantaneous spikes are handled, they're allowed to well surpass the ratings of the power supply. That's where the continuous vs max rating comes from.

Exactly, but you are talking about tapping into that "reserve" power as if it's ok to use all the time. That extra ~10A that the OCP is set at before it trips is the reserve power to handle spikes. Max might be 700W, but you need to plan on using only 550W. Earlier you mentioned or implied that it's ok to load that 550W PSU to 700W for 24/7 use for 10yrs and everything will be fine. If someone were to do that they would have one dead PSU because there is NOTHING left to handle a surge from the devices installed. I already know you are going to claim otherwise, but if you stop and look at others reaction to what you posted that's the impression we were left with.

I want to upgrade my ram and hard drives first then hopefully when 1080ti comes out i want to build another system.

You should be good upgrading ram/drives. Little things like that only change a draw of 12W or less. I'd be careful adding lots of drives as you might go over what your PSU can provide on the 3.3/5V rail if it's supplying so much to the 12V rail. But if you add a drive and pull one you should be fine.

WIll Corsair RM650X PSU Be Enough For 1080SLI

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