What is the problem pairing Seasonic S12ii 620W PSU with GTX 1080ti ?

[TechnoStyle]

https://seasonic.com/faq/#custom-collapse-0-63e8eb9921d6b91c69c9ecbd00490c41

Seasonic says : "It is very important to use a separate PCIe cable per slot with only one of the connectors attached to the GPU"

My PSU has 2 x 8 pin connector which comes from the same cable. (Daisy chained)
So, look for three PCIe Slots connection and "don't do this" type connection.

According to Seasonic FAQ:
Three Pci-e slot connection delivers 300W from single cable two 8 pin connection. --> No problem.
SLI/ Crossfire setup --> No problem.
Connecting them to single GPU --> DON'T DO THIS! (Why ? The same 300 W usage, why it causes problems ?)

What do you think about ? I think this is wrong. Are Seasonic serious ?
So I can't connect my S12 with 1080ti or any 2 x 8 pin GPU in the future ?
Also I can't connect it with 8+6 pin GPU (for ex. GTX 1080). Oh really ?

 

[13thmonkey]

I can only think of internal balancing, which when you have 2 cards goes away, but why, no idea.

 

[TechnoStyle]

MERGED QUESTION
Question from TechnoStyle : "Do anybody use GTX 1080 or above with daisy chained two 8 pin PCI-E cable ? Any problems ??"

Hello.
I have Seasonic S12ii-620W PSU.
It has one PCI-E cable which has two 8 pin connectors. (daisy chained from Seasonic. )
Seasonic says "Don't use daisy chained 8 pin connector for single GPU"
But I think this is wrong. There is no another manufacturer which gives the same warning AFAIK.

This PSU has single rail design. (According to reviews on the web and box label of the PSU.) And multi rail information is wrong AFAIK.
Also it has enough power for single GPU.
PCI-E 8 pin cables are 18 AWG in this PSU. Each cable can deliver 12V 10A in 0.7 meters with %3 acceptable loss. (120W per cable.)
If we look for 8 pin PCI-E pinout, we can see it has three +12V cable.
So three 12V cable, each can deliver 120W = 360 Watts.
Other cables are enough for grounding etc. purposes.
For example, GTX 1080ti consumes around 250W even on torture test. 60-75 W of power delivered from motherboard PCI-E slot.
Let's say 60W.
250-60 = 190W
If 18 AWG cables deliver up to 360W; 190W shouldn't make any problems i think.

So, do anybody use GTX 1080 or above with daisy chained two 8 pin PCI-E cable ? Any problems ?

 

[tokeylokey66]

Not like your card would explode. Basically my understanding is each 8 Pin will deliver 150 watts per cable. If you have 2 8 pins on a single cable they are sharing that 150 watts. So if your card needs to pull more your PC will freeze or shut down.

 

[13thmonkey]

Not like your card would explode. Basically my understanding is each 8 Pin will deliver 150 watts per cable. If you have 2 8 pins on a single cable they are sharing that 150 watts. So if your card needs to pull more your PC will freeze or shut down.

It depends on how calmly the psu shuts down, the seasonic will be nice and calm about it and probably turn on afterwards quite happily, cheap psu's will may well just explode.

 

[tokeylokey66]

Not like your card would explode. Basically my understanding is each 8 Pin will deliver 150 watts per cable. If you have 2 8 pins on a single cable they are sharing that 150 watts. So if your card needs to pull more your PC will freeze or shut down.

It depends on how calmly the psu shuts down, the seasonic will be nice and calm about it and probably turn on afterwards quite happily, cheap psu's will may well just explode.

True that, even though it is a low end Seasonic they are solid power supplies. I'm planning to get the modular version because my PSU is 7 years old. Doesn't show any signs of its age ... but i dunno i feel like its time. It's an antec BP 550 btw... very solid imo.

 

[Rexper]

Seasonic wouldn't post that chart if it didn't mean anything. Also, your PSU isn't really good, and based off a very old design. Not made for modern systems, and I highly recommended upgrading to a better, modern PSU if you're upgrading to the GTX 1080ti.

You can read a bit about it here: http://www.jonnyguru.com/forums/showthread.php?t=14939

 

[jankerson]

https://seasonic.com/faq/#custom-collapse-0-63e8eb9921d6b91c69c9ecbd00490c41

Seasonic says : "It is very important to use a separate PCIe cable per slot with only one of the connectors attached to the GPU"

My PSU has 2 x 8 pin connector which comes from the same cable. (Daisy chained)
So, look for three PCIe Slots connection and "don't do this" type connection.

According to Seasonic FAQ:
Three Pci-e slot connection delivers 300W from single cable two 8 pin connection. --> No problem.
SLI/ Crossfire setup --> No problem.
Connecting them to single GPU --> DON'T DO THIS! (Why ? The same 300 W usage, why it causes problems ?)

What do you think about ? I think this is wrong. Are Seasonic serious ?
So I can't connect my S12 with 1080ti or any 2 x 8 pin GPU in the future ?
Also I can't connect it with 8+6 pin GPU (for ex. GTX 1080). Oh really ?

You need to get a different PSU if you want to use a GTX 1080Ti.

Seasonic is serious about it also.

The S12ii is based off an old design and not designed for modern systems and the latest GPU's.

If you can afford a GTX 1080Ti then you can and should get a better PSU to run it.

Seasonic doesn't want people using the Daisy chain 6+2 x 2 on a single cable on 2x 8 Pin connections on the cards that will pull 225w or more.

I just spoke with Seasonic on this last week because the Prime Titanium 650w has 2x PCIe cables and 4x 6+2 connections. They don't recommend using a single cable for the GTX 1080 FTW2 even on THAT PSU.


Also Spoke with EVGA and they told me they don't recommend it either on ANY PSU, need to use 2 separate cables.


So the bottom line is if the PSU doesn't have 2 separate PCIe cables with 6+2 Pin connections then you can't use it.

 

[jankerson]

To help with pictures here are two Modular PSU's showing the PCIe Connections on the PSU end.

Here is the 650W Prime Titanium, has two PCIe cables (4 Connections) and 2 CPU 4x4 cables.

And the Seasonic X-650W, it has 4 separate PCIe cables (6+2) and 2 CPU cables (4x4 and 8 Pin).

 

[TechnoStyle]

I can't buy 1080ti. Too expensive for me. Graphics card which require more than 1 8 pin connector, generally expensive.
I though, I can get second hand one after 3-4 years. But I can also buy newer graphics card with same performance, similar price and much less power consumption in the future.
Anyway, for the wattage and single 8 pin connection, S12 is okay for my usage.
Now I'm thinking about the quality of it...

 

[jankerson]

I can't buy 1080ti. Too expensive for me. Graphics card which require more than 1 8 pin connector, generally expensive.
I though, I can get second hand one after 3-4 years. But I can also buy newer graphics card with same performance, similar price and much less power consumption in the future.
Anyway, for the wattage and single 8 pin connection, S12 is okay for my usage.
Now I'm thinking about the quality of it...

Nothing wrong with the quality, it's just based on an older platform and it's not modular.

Just remember 1 PCIe cable per 8 Pin connection on the high end cards ~ 225w

 

[TechnoStyle]

I can't buy 1080ti. Too expensive for me. Graphics card which require more than 1 8 pin connector, generally expensive.
I though, I can get second hand one after 3-4 years. But I can also buy newer graphics card with same performance, similar price and much less power consumption in the future.
Anyway, for the wattage and single 8 pin connection, S12 is okay for my usage.
Now I'm thinking about the quality of it...

Nothing wrong with the quality, it's just based on an older platform and it's not modular.

Just remember 1 PCIe cable per 8 Pin connection on the high end cards ~ 225w

Old group regulation design and HY510N protection IC are the problems.
I read 3.44 or 3.456V from 3.3V rail output via softwares when PC idle or light usage. It is within the ATX specs. (%5 tolerance). But it is very close to the upper limit, which concerns me a bit.
Software shows 3.42 - 3.44 V when I play Hitman 2017 game.

 

[jankerson]

I can't buy 1080ti. Too expensive for me. Graphics card which require more than 1 8 pin connector, generally expensive.
I though, I can get second hand one after 3-4 years. But I can also buy newer graphics card with same performance, similar price and much less power consumption in the future.
Anyway, for the wattage and single 8 pin connection, S12 is okay for my usage.
Now I'm thinking about the quality of it...

Nothing wrong with the quality, it's just based on an older platform and it's not modular.

Just remember 1 PCIe cable per 8 Pin connection on the high end cards ~ 225w

Old group regulation design and HY510N protection IC are the problems.
I read 3.44 or 3.456V from 3.3V rail output via softwares when PC idle or light usage. It is within the ATX specs. (%5 tolerance). But it is very close to the upper limit, which concerns me a bit.
Software shows 3.42 - 3.44 V when I play Hitman 2017 game.

You could update to the Focus+ or G-Series, both are updated designs and excellent. Also there are some great deals on the Prime Gold now.

I don't run a Focus, but I have a G-550W and it's excellent, I run a Prime Ti 650W, X-650W and G-550W currently.

Retired my M12ii 620W and M12ii 650W units.

 

[Rexper]

I can't buy 1080ti. Too expensive for me. Graphics card which require more than 1 8 pin connector, generally expensive.
I though, I can get second hand one after 3-4 years. But I can also buy newer graphics card with same performance, similar price and much less power consumption in the future.
Anyway, for the wattage and single 8 pin connection, S12 is okay for my usage.
Now I'm thinking about the quality of it...

Nothing wrong with the quality, it's just based on an older platform and it's not modular.

Just remember 1 PCIe cable per 8 Pin connection on the high end cards ~ 225w

Old group regulation design and HY510N protection IC are the problems.
I read 3.44 or 3.456V from 3.3V rail output via softwares when PC idle or light usage. It is within the ATX specs. (%5 tolerance). But it is very close to the upper limit, which concerns me a bit.
Software shows 3.42 - 3.44 V when I play Hitman 2017 game.

Good to see someone do some research on these forums rather than rely on a silly tier list.

Software voltage reading aren't always accurate as they are measured by an IC on the motherboard rather than the PSU itself.

Though those results don't surpise me all that much seeing the 3.3V rail could rise to 3.37V when it was new, as tested by Oklahomawolf: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=185

If your using the GTX 1080ti, I strongly suggest upgrading your PSU to a better quality DC-DC, with better protections aswell.

 

[jankerson]

I can't buy 1080ti. Too expensive for me. Graphics card which require more than 1 8 pin connector, generally expensive.
I though, I can get second hand one after 3-4 years. But I can also buy newer graphics card with same performance, similar price and much less power consumption in the future.
Anyway, for the wattage and single 8 pin connection, S12 is okay for my usage.
Now I'm thinking about the quality of it...

Nothing wrong with the quality, it's just based on an older platform and it's not modular.

Just remember 1 PCIe cable per 8 Pin connection on the high end cards ~ 225w

Old group regulation design and HY510N protection IC are the problems.
I read 3.44 or 3.456V from 3.3V rail output via softwares when PC idle or light usage. It is within the ATX specs. (%5 tolerance). But it is very close to the upper limit, which concerns me a bit.
Software shows 3.42 - 3.44 V when I play Hitman 2017 game.

Good to see someone do some research on these forums rather than rely on a silly tier list.

Software voltage reading aren't always accurate as they are measured by an IC on the motherboard rather than the PSU itself.

Though those results don't surpise me all that much seeing the 3.3V rail could rise to 3.37V when it was new, as tested by Oklahomawolf: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=185

If your using the GTX 1080ti, I strongly suggest upgrading your PSU to a better quality DC-DC, with better protections aswell.

The S12ii 520W that was reviewed back in 2010 was the old one before the updated models came out.

 

[Rexper]

Here's a review of the updated on I believe, https://en.gecid.com/power/seasonic_s12ii-520_bronze_ss-520gb_2015/?s=all

Includes 2 6+2pin PCIe connectors on one cable.

Protection IC is still HY510N, and 3.3V rail is reaches 3.39v. Still same platform as older version of unit.

 

[jankerson]

Here's a review of the updated on I believe, https://en.gecid.com/power/seasonic_s12ii-520_bronze_ss-520gb_2015/?s=all

Includes 2 6+2pin PCIe connectors on one cable.

Protection IC is still HY510N, and 3.3V rail is reaches 3.39v. Still same platform as older version of unit.

Still the older one.

The new ones had/have 5 year warranties.

The M12ii EVO is the same platform as the S12ii.

 

[Rexper]

Warranty was probably changed after the review. See here: http://www.realhardtechx.com/index_archivos/Page678.htm

Old S12ii had 1 6pin and 1 6+2 pin. New ones have two 6+2 pins on a 55CM + 10CM cable, exact same as the review, same as what OP has. Unless you would care to post what you believe is the right review...

Not sure the point of this argument is either. They're all the same platform, poor IC, group regulated and performance could be better.

 

[jankerson]

Warranty was probably changed after the review. See here: http://www.realhardtechx.com/index_archivos/Page678.htm

Old S12ii had 1 6pin and 1 6+2 pin. New ones have two 6+2 pins on a 55CM + 10CM cable, exact same as the review, same as what OP has. Unless you would care to post what you believe is the right review...

Not sure the point of this argument is either. They're all the same platform, poor IC, group regulated and performance could be better.

There aren't any current reviews, old models you know.

They are old platform.

In their day they were some of the best available, but that was 2010. (more so the M12ii's)

Things do however get better as time goes on, the reason why I recommended what I did.