recommendation for PSU for 8600k and 1080ti

chrcoluk · 21 Mar 2019 at 08:14

I think I am seeing signs I am pushing my PSU too far when playing division 2.

My current psu is 600watts but the 12v rail is limited to 40A 480 watts.

I see modern PSU's allow the 12v rail to use almost all of their capacity so e.g. 650watt PSU 54A 648 watts.

What seems to be happening is after several hours in game on my 1.031v 1974mhz 120% power limit profile on my 1080ti some cuda cores are getting turned off until I reboot as if the card is detecting a dangerous power state or something.

The reason I think cores are getting turned off is I see all the following symptons.

Power utilisation on the card drops sharply from 90-110% to around 70%.
Clock speed stays at 1974mhz
Performance significantly drops whilst pegging 99-100% GPU.

I have to reboot the system to recover proper behaviour, this problem doesnt occur on my lowest power profile which is 90% power limit, 0.875v and 1874mhz.

On the GPU 90% is 225 watts, 120% is 300 watts, OSD reports CPU on average is pulling 30-50 watts.

But I suppose to take into consideration power usage is not 100% efficient its a 80% rated PSU, its also a quite old PSU now, and the usage reported by software may not be accurate. So could be higher, especially on CPU where I dont think its reporting entire CPU package. These are also polled average figures so an average of 50w on cpu probably spiked higher.

so 300+50 = 350 add 20% loss of efficiency 420, on a 480 limit, add in spikes and I think I may have a problem.

Do you guys agree.

If you do whats a good replacement, I seen this PSU reccomended by others on here for intel cpu + 1080ti combo..

https://www.overclockers.co.uk/ante...plus-gold-modular-power-supply-ca-24n-an.html

Although its only an extra 50 watts I noticed the 12v rail has a much higher limit of 54A 648w vs what I have now of 480w.

Is there better suggestions?

Thanks

Update - in hwinfo64 max cpu core power is peaked at 100W, so I think I do need a new psu, if that happened whilst GPU was pulling 250-300.

chrcoluk · 21 Mar 2019 at 08:28

probably would be this instead as I need floppy connector for sound card and have 8 sata devices.

https://www.overclockers.co.uk/antec-hcg-gold-650w-80-plus-gold-modular-power-supply-ca-24w-an.html

pastymuncher · 21 Mar 2019 at 10:41

What you have to remember is that the 1080ti can easily pull more than 300w just by itself, especially if overclocked. The rest of the 1000 series gpu's are pretty efficient but that went out the window when the 1080ti launched. To be absolutely safe and to provide enough spare headroom for future upgrades I would probably go with the 750w version.

My basket at Overclockers UK:

1 x Antec HCG Gold 750W 80 Plus Gold Modular Power Supply= £102.95
1 x Seasonic Focus Plus 750W 80 Plus Gold Modular Power Supply= £104.99

chrcoluk · 21 Mar 2019 at 10:59

to pure gaming with a 980ti you recommended the 650w model saying "its more then enough" yet the 1080ti only uses an extra 20 watts under load vs the 980ti. You have changed your view now on that? His cpu is also heavier on power usage than mine as its HTT vs non HTT.

https://forums.overclockers.co.uk/threads/recommed-me-psu-wattage.18828649/

pastymuncher · 21 Mar 2019 at 13:30

I thought you were wanting efficiency? A 750w psu should be more efficient than a 650w psu when you are running at full load. Are you going to be overclocking that 1080ti? I just checked a couple of reviews and when overclocked your card can draw up to 375w by itself with the power slider at full. The 750w Antec is only a tenner more than the 650w.

fastboy · 21 Mar 2019 at 14:20

I have been running my 8600k at 4.8ghz,and a watercooled zotac 1080ti quite happily on my EVGA GS550w.
I know when I tested it on the wall socket I was drawing 490 watts total maxed out with OC on both

chrcoluk · 21 Mar 2019 at 16:09

in the end I thought I been silly its only a tenner for the 750w over the 650w but order already shipped. However I think it will be fine as its over a 150w boost on the rail.

In terms of efficiency I dont know how much a difference it will make I think most of the power utilisation isnt close to the limit, its occasional spikes that are the issue. Hence it taking several hours for any issue to occur on my existing psu.

My gpu config is detailed in my post.

Power capped to 300w in division 2 but in most games I cap it to 225w. (the slider maxes at 150% so my 120% isnt max).

Its undervolted for the clocks it runs at hence been able to sustain close to 2ghz without needing max slider. I realise a cap is probably breached for short bursts tho.

90% of the time in divison 2 the utilisation is about 60% and power usage about 80%. Thats when outside, indoors its even lower.

chrcoluk · 21 Mar 2019 at 16:17

fastboy said:
I have been running my 8600k at 4.8ghz,and a watercooled zotac 1080ti quite happily on my EVGA GS550w.
I know when I tested it on the wall socket I was drawing 490 watts total maxed out with OC on both

yeah just checked your psu has a better 12v rail then mine as well, 48a vs 40a.

Its possible the psu isnt the problem here, I replace it and the issue persists, I wont know till I swap it.

fastboy · 21 Mar 2019 at 16:37

well I guess it wouldn't hurt,at least its peace of mind

chrcoluk · 22 Mar 2019 at 10:41

Well I will be returning the PSU I think. (still shrinkwrapped box)

So hardOCP review of the PSU clearly shows it as 54A rating on the 12v rail.

https://www.hardocp.com/article/2018/07/24/seasonic_focus_plus_gold_650w_power_supply_review/2

here is mine, seems also less pcie cables perhaps linked to weakening of 12v rail.

A poster on here also said this is essentially the same PSU as the antec 650 HCG Gold PSU which is 54A on the 12v rail as seen in the OCUK picture.

But it looks like some bait and switch has been happening.

The spec on the box whilst it still shows 648w for the 12v it now shows only 45A instead of 54A for the rail.

fastboy · 22 Mar 2019 at 10:52

aye I would be sending it back too if that's happened.

must admit I have been looking for a slightly bigger psu and wouldn't hesitate to go EVGA again.

https://www.custompcguide.net/evga-power-supply-side-by-side-comparison-tool/

you can change the page for different psu and it lists all the specs.

chrcoluk · 22 Mar 2019 at 11:20

their own website still has it as 54A as well, https://seasonic.com/focus-plus-gold (have to select 650w model at top of page to see specs at bottom for rail)

That sticky label at the top left by the way was conveniently stuck over the 12V spec, I had to move it to see it

fastboy · 22 Mar 2019 at 11:26

yes I see.sadly at the bottom of the page:

Specifications are subject to change without prior notice.

chrcoluk · 22 Mar 2019 at 11:35

OCUK are aware now and someone is going down to the warehouse to check the packaging of their stock.

I have ordered the HCG 750W now and hope thats not been bait and switched.

chrcoluk · 22 Mar 2019 at 14:26

Response from seasonic indicates its a typo. I cannot honour their request to open the box tho as I told OCUK it would be returned shrinkwrapped.

Thank you for contacting Seasonic.

It looks like a typo error as the PSU specs didn't change and so are the components inside. Would it be possible to have a picture of the serial number too and check on the PSU if you have the same or not?
We will escalate this error asap.

Thank you and sorry for the inconvenience.

EsaT · 22 Mar 2019 at 17:40

Seasonic isn't maker changing PSU design without changing also model name.

45A is 12V rating of 550W model, so someone likely made copy&paste error in box design.
In modern DC-DC designs 12V can't really be lower than full power:
3.3V and 5V are done from 12V using smaller step down switchers.

chrcoluk · 23 Mar 2019 at 15:47

Done the PSU swap, I have never had such a hard time swapping a component, the cables are very thick and inflexible, and specifically the cpu 2 x 4 pin cable, has a very small separation, took me 3 hours.

Also the clips dont give a click sound when inserting so no audible indication a cable is fully secured in place. The 24 pin board cable is at full stretch between PSU and board whilst been routed through back of case, deffo could have been made a bit longer or the same length would have been ok if it was so think and rigid.

But the size of the PSU shows how tech has progressed, its smaller than the older PSU yet a higher capacity.

chrcoluk · 23 Mar 2019 at 17:17

Well the GPU is behaving differently in division 2.

Previously it would goto my max clock set on my voltage curve when entering the game, and it would stay at that clock (As never hit power limit), but would drop one bin based on temperature.

Now with new PSU installed its hovering between intermediate clocks so been less aggressive in ramping up clock speed, as a result power usage is way lower, I quickly fired up unigine heaven and that does ramp up to full clocks and high power usage just fine, so it seems the card is able to run at high power load, but its deciding to behave different in game now.

As far as I can tell no new patch was downloaded for the game, the drivers are unchanged, same config in afterburner etc is kind of weird. But framerate rate seems fine so I am going to just play the game and see how it goes.

chrcoluk · 24 Mar 2019 at 22:19

Early days but no incidents since PSU swapped, 3 long gaming sessions. The clock speed weirdness I got old behaviour back by setting nvidia profile for the game to high performance, but I may later switch it back to optimal power for the power savings.

However I am now having to disable my headphone amplifier as its amplifying interference from PSU to my soundcard. My old PSU didnt do that, so will need to think on what I do about that long term.