Corsair SF450 with MSI Gaming trio X 3090 GPU - 3x Cables?

[Oliveros]

I have an MSI Gaming trio X 3090 GPU that requires 3x PCI-E Cables from PSU and I'm planning to buy the Corsair SF450 to power only the GPU alone in my workstation (lian-li pc that can handle two PSUs)

 

The SF 450w Comes with 2x PCI-E Cables and 1x 4+4CPU.

 

can I connect 3x PCI-E Cables to it instead of connecting the third 4+4CPU? so I can use all three outputs directly to the msi 3090?

 

the main issue is that the PSU comes with only 2x PCIe cables (check image) 2x total connectors 1x connection per cable. Can I buy an extra one and connect it? or use another one?

[mariushm]

I have serious concerns about how safe it would be to do this.... the 3090 goes above 350 watts with peaks up to 415w in gaming and may have small bursts up to even higher power thresholds (450w was seen in benchmarks).

 

That 450w psu will basically run at 80-90% of its maximum output or more each time you'll play ... not to mention the card will get some voltage through the pci-e slot, and another voltage from the second power supply.  Also, some power supplies don't output all wattage on 12v alone, so double check the label of that sff power supply... it may only output up to 400-420w on 12v, not 450w.

 

Also consider how noisy such power supply will be at 80-90% load and how much heat it will make (is it bronze efficiency, gold?)

 

 

[Oliveros]

Copy that! I can go for the SF 600w then but same issue with the cables. any idea for how can I connect them? because the SF600 comes also with 2x PCIe cables and 4+4 CPU one 

[mariushm]

You could order a custom cable from cablemod or other such store or just use cables with 2 pci-e 8pin per cable .. the individual cables going out the power supply and the headers on the psu can carry more than 150 watts.

But again, using a separate power supply for the video card alone is not a great idea. 

It would be much safer (and better) to just use a 850w or higher power supply to power everything. 

 

 

[Spotty]

Which power supply do you have for the system already? Is it not powerful enough to power the entire system with the graphics card?

 

17 minutes ago, Oliveros said:

can I connect 3x PCI-E Cables to it instead of connecting the third 4+4CPU? so I can use all three outputs directly to the msi 3090?

You can. The SF450 uses type 4 PCIe cables (which are also interchangeable with Corsair's type 3 PCIe cables). You can buy replacement cables from Corsair's website as well as from third party cable makers like cable mod.

 

One thing to keep in mind is the length of the cables with SFF power supplies. Typically much shorter than normal cables since they're meant for smaller cases with less room distance between PSU and components.

 

11 minutes ago, mariushm said:

Also, some power supplies don't output all wattage on 12v alone, so double check the label of that sff power supply... it may only output up to 400-420w on 12v, not 450w.

 

Also consider how noisy such power supply will be at 80-90% load and how much heat it will make (is it bronze efficiency, gold?)

For the Corsair SF450 it's 37.5A on 12V (full 450w) and they're in either 80+ gold or 80+ platinum versions.

 

Though I do share mariushm's concerns about running a 3090 on a 450w PSU.

I would much rather just use one good quality beefy PSU to power the whole system. 

[Oliveros]

Ok, I have the Corsair HX1200w that is powering the whole system. 

 

System Specs:

MB: Asus Zenith II Extreme Alpha

RAM: Corsair Vengeance Pro 256GB Kit

Cooling: NZXT Z73

NVME: 980Pro x2

GPU: msi gaming trio X 3090

 

the main issue is that the 1600w are out of stock and/or they are way expensive.

 

this is why i'm looking for a safe way to get another SF600 for example and connect it with the HX1200 with the dual psu cable: https://www.amazon.ae/gp/product/B09295Z7M3/ref=ox_sc_act_title_2?smid=A5PQZB4MA4IOP&psc=1 (image attached) to power the 3090 alone.

 

what do you think? 

 

[Spotty]

1 minute ago, Oliveros said:

Ok, I have the Corsair HX1200w that is powering the whole system. 

The HX1200 would be more than capable. It's only the one RTX 3090, right? You're not trying to power 5 of them for mining?

[jaslion]

The hx1200 is plenty good to power your system with a 3090 in it no sweat.

[Oliveros]

oh really ? forgot to mention that I have the Threadripper 3970X too running at 4GHz 

 

I was checking https://outervision.com/power-supply-calculator and found that I need more power if I overclocked the CPU to 4.2GHz max and the msi at max boost clock speed if i'm rendering or something. they suggest a 1300W psu.

 

what do you think? 1200w is enough ?

[mariushm]

The outervision site is bullshit. For example it lists 32A on 5v ... that's stupid. Unless you have 20-30 SSDs and mechanical hard drives, your PC is not gonna consume more than 10-15A on 5v

 

The 3970x will consume around 300w-320w overclocked, at full load. See https://www.anandtech.com/show/15044/the-amd-ryzen-threadripper-3960x-and-3970x-review-24-and-32-cores-on-7nm/2

 

The motherboard will consume maybe 20-30w on 12v, basically in powering fans and maybe the ram sticks (though a lot of motherboards use 5v to 1.2-1.35v dc-dc converter to power the ram sticks, around 1-2w per stick). 

 

So let's say 400w for cpu+mobo+cooler/aio + 450w for video card = 850w on 12v ... you still have A LOT of room up to 1100w on 12v (1200w psu, but 100w or so you reserve for the 3.3v and 5v)

 

[Oliveros]

cool thank you! is that correct that the vengeance pro 256gb rams will take 233w of power according to pcpartpicker? check attached

[mariushm]

That's ridiculous... no.  

Anything more than around 10 watts would need to be cooled with a fan, especially when the sticks are so close together. For comparison, the x570 chipset consumes up to around 15 watts and needs a fan to stay cooled. 

 

How much a stick consumes depends on the number of chips on it and frequency and voltage, a typical stick with 8 chips on it consumes around 2 watts.

Crucial says for a  8 GB stick you should allocate around 3 watts :  https://www.crucial.com/support/articles-faq-memory/how-much-power-does-memory-use

 

So let's be conservative and say that each 32 GB stick will consume 4 x 3w (for each 8 GB chunk) = 12 watts. In reality, it's probably gonna be under 10 watts.

 

You have 8 sticks, so just assume these 8 sticks are gonna consume at most around 80-90 watts. If you keep them at 1.2v it wouldn't surprise me if they consume around 50 watts.

I went with the assumption you had 16-32 GB when I said 20-30w for ram and motherboard.

 

Either way, you're still way below that 1200 watts. 

 

I can tell you that the kingpin card will consume more than 350 watts, but the motherboard will consume much less, should be less than 40-50w (chipset, onboard audio, extra controllers, powering extra fans etc)

 

 

[Spotty]

25 minutes ago, Oliveros said:

cool thank you! is that correct that the vengeance pro 256gb rams will take 233w of power according to pcpartpicker? check attached

That seems high to me.

 

This page from Crucial estimates 3W per 8GB, which is backed up by Tom's Hardware testing measuring 2.98W/8GB.

https://www.crucial.com/support/articles-faq-memory/how-much-power-does-memory-use

https://www.tomshardware.com/reviews/intel-core-i7-5960x-haswell-e-cpu,3918-13.html

 

Should be around 3W per 8GB of 2133MHz at 1.2V. Since you're running 3200MHz at 1.35V it will be a little higher, would have to guess but say around 3.5W. For 32GB sticks you're looking at around 12-14W per stick or around 96-112W total. But then you would also need to add a few extra watts to each stick for the RGB lights, I have no idea how much power they draw and it would depend on what colour they are displaying but let's say 2W per stick of memory for RGB adding another 15W or so for a total of around 115-130W for the memory. That still seems high to me for memory and I wouldn't be surprised if it actually draws less than that, but it's still almost half what PCPP estimates.

 

 

My advice: Just try using the HX1200 with the system. It should work, 1200W is a lot even for a high end system like that. If for whatever unforeseen reason it doesn't work and it randomly shuts down under load due to not being able to provide enough power then you could look at replacing the PSU.

Is it the HX1200 (grey label) or the HX1200i (blue letters on label)? The HX1200i includes digital monitoring so you can use iCue to see how much power the system is drawing.

[mariushm]

Keep in mind the article was from 2014 and DDR4 was still relatively new, and they made the chips using older processes (probably 32-20nm -ish) 

Nowadays they use 12nm or even lower processes for some chips, so they save power.

 

Also, back then 16 Gbit (2 GB) chips were less common, they tended to use 4 Gbit and 8 Gbit chips to build sticks (8 x 8 Gbit = 8 GB , or 16 x 4 Gbit = 8 GB stick) 

 

Nowadays, the 32 GB you buy will probably use 16 Gbit (2 GB) chips, so you'll have only 16 chips of 2 GB each on the stick, therefore it may use less power than 4 independent 8 GB sticks. 

 

It's quite possible you'd be able to keep all 8 sticks at 3200 Mhz ... but I don't think you'll have a significant drop in performance if you run them at 1.2v and  2666 mhz or even 3000 mhz to keep them cooler and less power hungry. 

 

[Spotty]

1 hour ago, mariushm said:

Keep in mind the article was from 2014 and DDR4 was still relatively new, and they made the chips using older processes (probably 32-20nm -ish) 

Nowadays they use 12nm or even lower processes for some chips, so they save power.

 

Also, back then 16 Gbit (2 GB) chips were less common, they tended to use 4 Gbit and 8 Gbit chips to build sticks (8 x 8 Gbit = 8 GB , or 16 x 4 Gbit = 8 GB stick) 

 

Nowadays, the 32 GB you buy will probably use 16 Gbit (2 GB) chips, so you'll have only 16 chips of 2 GB each on the stick, therefore it may use less power than 4 independent 8 GB sticks. 

Good point. The Tom's Hardware article measuring 2.98W was from Haswell E era. Should be a little less now.

 

1 hour ago, mariushm said:

It's quite possible you'd be able to keep all 8 sticks at 3200 Mhz ... but I don't think you'll have a significant drop in performance if you run them at 1.2v and  2666 mhz or even 3000 mhz to keep them cooler and less power hungry.

I have a feeling that someone who spent over $1000 on a motherboard and $1700 on RAM is not going to run their memory at 2666MHz just to save a few watts

Edited June 15, 2021 by Spotty

[tdkid]

i would not do this because the GPU seems that its always going to be on with no control from the motherboard. using the EVGA power meter as its the only one i have found and not knowing the exact specs of your system, your current build how i did it with the 1 3090, TRX40 board with 3970x threadripper, 1 SSD and 1 HDD yes to overclock takes 898w so its reccomeding anything 1000 or above.

 

EVGA - Power Meter

[Spotty]

27 minutes ago, tdkid said:

i would not do this because the GPU seems that its always going to be on with no control from the motherboard. using the EVGA power meter as its the only one i have found and not knowing the exact specs of your system, your current build how i did it with the 1 3090, TRX40 board with 3970x threadripper, 1 SSD and 1 HDD yes to overclock takes 898w so its reccomeding anything 1000 or above.

 

EVGA - Power Meter

The EVGA power meter is just as useless as all the other power calculators. I just put in my system and it says it would consume 645W. My system is under load right now doing F@H and sitting at 240W power draw measured at the wall. In the past I've overclocked my CPU to 4.8GHz at 1.45V and ran the GPU overclocked with 150% power limit running Furmark + Cinebench and barely broke 550W. I don't think I could push my system to draw 650W without extreme overclocking or adding another graphics card.

[tdkid]

2 minutes ago, Spotty said:

The EVGA power meter is just as useless as all the other power calculators. I just put in my system and it says it would consume 645W. My system is under load right now doing F@H and sitting at 240W power draw measured at the wall. In the past I've overclocked my CPU to 4.8GHz at 1.45V and ran the GPU overclocked with 150% power limit running Furmark + Cinebench and barely broke 550W. I don't think I could push my system to draw 650W without extreme overclocking or adding another graphics card.

well then i say its pretty accurate as its there to give you a reccomendation above what it thinks you would ever be able to do. for example i have a RTX 2070 super, MSI z370, i7 8700k, 0 SSDs 1 HDD and not OC, "wattage calculated" 475, reccomend anything 500 and up. i have an EVGA supernova 1000G+. i dont think i will ever reach this limit either but i have room to spare if i do get close.