Seasonic X-Series 750W Gold and dual 2080Ti

[Timmah!]

Hello there,

as the title says, i intend to buy 2x 2080Ti graphics cards, while boasting 750W X-Series Gold Seasonic PSU. Do you think it could be enough, or not a chance? I am really not educated in this kind of stuff regarding electricity, so i would prefer more elaborate response from someone, who really has clue. I guess usual answer from most people would be "better get 1300W PSU hurr durr, just to be on the safe side", but i dont see any reason to do that, unless i am told by someone who is clearly into this stuff, that i NEED to do that (or simply get bigger PSU). It may not to look that way, but my wallet is not bottomless :-D, and those cards are already massive investment, i would prefer not to spend another 300 EUROs on bigger quality PSU, if i dont have to.

The cards themselves are rated at 260W TDP and apparently that is more or less their power consumption, so i would be looking at say about 550W just for them - before the rest of the system comes into equation. I would assume those 200W might be good enough for it to fit, but thats the thing, i dont really understand the stuff regarding PSU efficiency, whether its actually capable of powering components asking for more power than its rated for etc, what mean those AC/DC measurements in PSU reviews, what people mean by "power at wall" (how that differs from power consumption of the parts inside computer on their own), etc...... hence this topic.

My CPU is 7940x OCed to 4,1GHz at all cores and per Core Temp it consumes about 250W under full load during Cinebench run. However, during gaming, computer intensive game like Ashes:Escalation (benchmark) its only about 80W in GPU focused bench and 150W in CPU focused bench... i really dont see any real-world scenario, where i would get both CPU and GPUs pegged to their full potential at the same time - in which case the PSU rating would be exceeded no doubt. I actually dont even intend to game in SLI mode - i am buying 2 cards strictly for Octane Render related work, which being pure GPU render, utilizes CPU only relatively lightly during the rendering itself.

Finally, until now i have been on the same system, just with 2x GTX 1080 FTWs (which were rated at 210W IIRC), sometimes overclocked to 2GHz+ and had no issues at all. Granted, even 100 additional Watts for 2080Ti´s may cross it and cause them.

Thanks it advance for your advices

 

[mnewsham]

You should be fine in pretty much any "normal" situation. If you did end up fully loading the 2080Ti's AND the OC'd CPU, you could have some problems, though even then if it weren't a sustained load I imagine it'd be okay.

You'll certainly be pushing the limit though, in games that can actually stress both GPUs and a least a bit on the CPU you could see total system power draw around 600-700w.

 

[Markfw]

I would say at least 700; If you want to be sure you don;t blow the PSU I would have at least 1000 watt quality, as then its at 70%load.

 

[Timmah!]

Thank you both.

I am aware i can come close to that limit and have total system draw perhaps up to those 700W - but is that an issue with 750W? Are the PSUs not build to sustain their rated power consumption? Especially high quality ones like i assume mine is?

 

[Markfw]

Thank you both.

I am aware i can come close to that limit and have total system draw perhaps up to those 700W - but is that an issue with 750W? Are the PSUs not build to sustain their rated power consumption? Especially high quality ones like i assume mine is?

Thats like running your car at 500 rpm less than redline 24 hours a day. OK, maybe it can handle it, but would you take a chance ? When a PSU goes, it usually takes half the components with it. Not chancing it myself.

 

[UsandThem]

One thing to consider that I found out the hard way when I bought my Seasonic Ultra Gold 750w and wanted to run a couple cards with it, is a card like the GTX 1080ti (or GPUs that use more than 220w), Seasonic specifically states to use separate PCIe cables for each connection on the card.

So even though the PC I wanted to do this in would have never come close to using 750w, I was limited because the 750w only came with 2 cables (4 x 6+2 pin connectors). Since I had to use one cable for each connection on my 1080ti, I couldn't use the other GPU in the PC.

https://seasonic.com/faq

 

[Timmah!]

One thing to consider that I found out the hard way when I bought my Seasonic Ultra Gold 750w and wanted to run a couple cards with it, is a card like the GTX 1080ti (or GPUs that use more than 220w), Seasonic specifically states to use separate PCIe cables for each connection on the card.

So even though the PC I wanted to do this in would have never come close to using 750w, I was limited because the 750w only came with 2 cables (4 x 6+2 pin connectors). Since I had to use one cable for each connection on my 1080ti, I couldn't use the other GPU in the PC.

https://seasonic.com/faq

Huh...really? I think i had it this way until now with 2 1080s - without any issues. But i was totally not aware of that. If they deliver 4 8pins with their PSU, one assumes its because they assume you would want it to power 2 GPUs. Is this not more of a cable issue anyway? I mean solvable by buying and using 2 additional cables.

 

[UsandThem]

Huh...really? I think i had it this way until now with 2 1080s - without any issues. But i was totally not aware of that. If they deliver 4 8pins with their PSU, one assumes its because they assume you would want it to power 2 GPUs. Is this not more of a cable issue anyway? I mean solvable by buying and using 2 additional cables.

GTX 1080s don't pull enough to warrant the "caution" from Seasonic, since they top out around 180w. My GTX 1080ti can pull up to 280w (mostly only in synthetic benchmarks, not in "real world" usage).

You can buy extra cables, but they are pricey. You'd come out better (and cheaper) by buying a unit that comes with 4 cables to begin with. Like others here have stated, you don't want to run a PSU that close to its max all the time. It will make it run hot, and your efficiency drops when you are at 80% and above. It differs for each PSU, but that seems where many units have lower efficiency.

 

[Timmah!]

GTX 1080s don't pull enough to warrant the "caution" from Seasonic, since they top out around 180w. My GTX 1080ti can pull up to 280w (mostly only in synthetic benchmarks, not in "real world" usage).

You can buy extra cables, but they are pricey. You'd come out better (and cheaper) by buying a unit that comes with 4 cables to begin with. Like others here have stated, you don't want to run a PSU that close to its max all the time. It will make it run hot, and your efficiency drops when you are at 80% and above. It differs for each PSU, but that seems where many units have lower efficiency.

Thank you. I have/had evga FTWs (sold one already), with 2 8pins and rated at 215W TDP and i assume overclocked might have drawn even more than that (but surely not 280W). So they did not top at 180W.

Anyway, i checked the PSU prices and they are actually quite lower than 2 years ago, when i got this PSU - now Seasonic Prime Gold 1000W is 185 EUROs around here, 1300W one 220 EUROs. I assumed it will be more like 300 - 500, cause IIRC i paid about 250 EUROs for this 750W one. So i guess i will follow your advice.
The question then remains - 1000W or 1300W? :-D I guess those additional 40 EUROs are acceptable, but why spend them, if already 1kW is plenty.

EDIT: Alternatively, the question might be, whether 1000W Gold ULTRA or 1000W Titanium - not ultra, at the same price.

 

[UsandThem]

Thank you. I have/had evga FTWs (sold one already), with 2 8pins and rated at 215W TDP and i assume overclocked might have drawn even more than that (but surely not 280W). So they did not top at 180W.

Anyway, i checked the PSU prices and they are actually quite lower than 2 years ago, when i got this PSU - now Seasonic Prime Gold 1000W is 185 EUROs around here, 1300W one 220 EUROs. I assumed it will be more like 300 - 500, cause IIRC i paid about 250 EUROs for this 750W one. So i guess i will follow your advice.
The question then remains - 1000W or 1300W? :-D I guess those additional 40 EUROs are acceptable, but why spend them, if already 1kW is plenty.

If I was facing the decision, I'd get the 1000w, as it will be plenty. 1300w is too much IMO. Anandtech has total system draw with one GTX 2080ti at 446w (using an overclocked Intel 7820X which is a 140w TDP):

Add another card in pulling a maximum of 300w (should be lower than that though), and you are at 750w maximum.

The prices of the larger PSUs have fallen quite a bit along with GPUs due to the mining crash. They must have increased production during that period, and now they likely have excess inventory.

 

[Campy]

750W is probably the minimum I would want to have with those cards. If overclocking the cards and CPU 850W or 1000W, I would probably choose the 1000W myself.

 

[Markfw]

Thank you. I have/had evga FTWs (sold one already), with 2 8pins and rated at 215W TDP and i assume overclocked might have drawn even more than that (but surely not 280W). So they did not top at 180W.

Anyway, i checked the PSU prices and they are actually quite lower than 2 years ago, when i got this PSU - now Seasonic Prime Gold 1000W is 185 EUROs around here, 1300W one 220 EUROs. I assumed it will be more like 300 - 500, cause IIRC i paid about 250 EUROs for this 750W one. So i guess i will follow your advice.
The question then remains - 1000W or 1300W? :-D I guess those additional 40 EUROs are acceptable, but why spend them, if already 1kW is plenty.

EDIT: Alternatively, the question might be, whether 1000W Gold ULTRA or 1000W Titanium - not ultra, at the same price.

Since I have 4 boxes with dual 1080TI FTW3's, I think I am qualified to answer. They are all 4 threadrippers, and the CPU and both video cards are running 100%load 24/7/365.and run about 700 watts load. All have Corsair AX1200's. I probably could have made do with 1000 watt units, but with that constant load, it makes me feel better.

As far as the power connectors, I have all of them using the "not recommended" way. Thats the first I have heard/seen of that, so its up to you, I have no comment.

 

[Shmee]

All advice here is pretty sound IMO, but I will add something. If I recall, the X series is an older Seasonic model, and you stated you bought it 2 years ago, so keep in mind PSUs also can degrade over time.

I would likely go with a 1000W for safety, and that would be fine. Of course if you want to go higher, it may be overkill, but if not too much more money, it couldn't hurt, and the PSU might last longer at load.

 

[Hans Gruber]

You need at least an 850w power supply. I think 1000w would be overkill but would give you a better margin. I think 1000w is the next level after 850w power supplies.

 

[mnewsham]

. If I recall, the X series is an older Seasonic model, and you stated you bought it 2 years ago, so keep in mind PSUs also can degrade over time.

Yeah, the X series 750W released in 2009/2010 if I remember correctly. While it IS a high end PSU, and overall a great unit, PSUs have improved a fair amount over the last ~8+ years.

He's probably fine using this 750w unit, but it wouldn't be a terrible idea to replace it with a newer gold/platinum/titanium rated 850w seasonic or similar high quality unit.

No need to jump to 1000w, but 850w would give you some comfortable buffer room.

 

[Timmah!]

Many thanks to everyone. I decided to take your advice and added to my GPU order new PSU as well - ultimately i went for the 1kW Seasonic Prime Ultra Gold. Hopefully its a good choice. 850W might have been maybe OK too, after all i planned to get away with 750W one, but since i am paying extra for new PSU, i wanted to have a bigger headroom than 100W against what i already have. The price difference is rather small between them anyway.

 

[Campy]

That's a really good unit. 12 years mfr warranty too.

 

[VirtualLarry]

Very nice choice. I was going to add, since no-one mentioned it. Back in the days of Maxwell, there was a site that measured "instantaneous" load on the +12V line by a high-end GPU, and while the average power usage basically matched up with TDP, there were "instant spikes" that went rather WAY higher.

Whether this was an artifact of how the were measuring, or what, I cannot say. But suffice to say, you might need a bit 'o headroom on your PSU, with a higher-end modern NVidia-arch dGPU, due to these "power spikes".

 

[Jjoshua2]

I'm having issues with this sort of setup with a 1000w Seasonic and 2 x 2080 but I'll make a new thread, but OP should probably follow it since it's almost exact same situation.