GTX 1080 Ti SLI possibly overwhelming PSU

[PCMasterDebater]

18 hours ago, quan289 said:

Considering how he is powering said setup shows that a quality 850w PSU is capable of powering it.

You're not helping the OP with this nonsense, you're confusing him. I'm not going to regurgitate the same shit over and over though when all the information is readily available for him to make the CORRECT choice in this matter. I'm sure he already googled it and realized how wrong you are. 

 

OP, you need a Seasonic, XFX, or Superflower 1000w PSU or greater. Simple as that. Personally, I go with Seasonic.

[aL_eX]

7 hours ago, quan289 said:

TBH, even if you were to get the power readings from your meter, it wouldn't explain your issue (you could used it if you feel the need to replaced it - I don't think you do). There isn't any sort of data connection between the PSU and your system that make your GPUs detect what power supply you are using. The PSU is supplying power to your system on demand. If your GPUs demands a 600wDC power draw for that application / instance, it will draw 600wDC regardless if it's 750w or 1600w. If it exceeds what the PSU is design to be able to output, it is the PSU job to cut power to the system via the safety protections integrated in the PSU ( for example, Over Power Protection / OPP), which your system is still running and able to complete all of its tasks.

 

Of course, a low quality (which the 850 P2 isn't) or defective PSU can lead to stability issues such as your system crashing / locking up; however, it shouldn't be affecting your system performance in that sort of manner. There's a possibility of a driver issue, as well as your situation remind this thread on reddit where s/he saw both low CPU and GPU usage but fixed it with an CPU overclock : https://www.reddit.com/r/nvidia/comments/3pob04/are_my_980_tis_in_sli_only_supposed_to_be/

I'm actually starting to think it might be a driver issue. The thing is, my CPU is already overclocked to 4.2GHz, and going any higher would require 1.45V, which I'm not comfortable with using for extended periods of time. Is there a way to uninstall old GPU drivers (I had a GTX 660 prior to the upgrade) or make sure that they are installed correctly?

[stealth80]

1 hour ago, PCMasterDebater said:

You're not helping the OP with this nonsense, you're confusing him. I'm not going to regurgitate the same shit over and over though when all the information is readily available for him to make the CORRECT choice in this matter. I'm sure he already googled it and realized how wrong you are. 

 

OP, you need a Seasonic, XFX, or Superflower 1000w PSU or greater. Simple as that. Personally, I go with Seasonic.

Regardless, psu wouldn't cause the op problems, it would be unstable or shut down. I agree 850w is probably on the low side with regards efficiency for oc x99 and 2x 1080 in sli but it should run it. Remember 1080ti is the fastest gpu and he's using 2 I think this is a utilisation issue 

[aL_eX]

1 hour ago, PCMasterDebater said:

You're not helping the OP with this nonsense, you're confusing him. I'm not going to regurgitate the same shit over and over though when all the information is readily available for him to make the CORRECT choice in this matter. I'm sure he already googled it and realized how wrong you are. 

 

OP, you need a Seasonic, XFX, or Superflower 1000w PSU or greater. Simple as that. Personally, I go with Seasonic.

Thanks for the suggestion. I found an EVGA SuperNova G3 1000W on amazon for £160, compared to the Seasonic PSU which is over £250 (pricing in the UK is really weird for PC components). Would you recommend that EVGA PSU?

[stealth80]

18 minutes ago, aL_eX said:

Thanks for the suggestion. I found an EVGA SuperNova G3 1000W on amazon for £160, compared to the Seasonic PSU which is over £250 (pricing in the UK is really weird for PC components). Would you recommend that EVGA PSU?

Evga will be fine, I'm however not convinced this issue is your psu 

 

http://www.guru3d.com/articles_pages/geforce_gtx_1080_ti_review,7.html

 

says here a good 800w psu should be enough but I still think a good 1000w is in the order

[stealth80]

11 hours ago, aL_eX said:

The CPU usage is about 30% - 40% and I'm playing at 1440p 165Hz. I'll try and bring the CPU back to stock frequency and see what difference it makes, but I'll probably do that tomorrow after my power meter arrives (which will definitely shed some light on the problem).

Had a thought. Can you try running a few games with dsr set to 1.5 or 2? This should work the GPUs harder and eliminate any cpu bottleneck, check cpu and gpu utilisation throughout. If it stays the same we can look at other aspects 

[stealth80]

Also look here, I think you have some bottleneck 1080ti is too damn fast 

 

https://uk.hardware.info/reviews/7270/21/nvidia-geforce-gtx-1080-ti-review-incl-sli-faster-card-for-the-same-price-gtx-1080-ti-slinperformance

 

 

https://uk.hardware.info/reviews/7270/22/nvidia-geforce-gtx-1080-ti-review-incl-sli-faster-card-for-the-same-price-gtx-1080-ti-slinperformance-per-game

 

[aL_eX]

13 minutes ago, stealth80 said:

Had a thought. Can you try running a few games with dsr set to 1.5 or 2? This should work the GPUs harder and eliminate any cpu bottleneck, check cpu and gpu utilisation throughout. If it stays the same we can look at other aspects 

Using 2x and 4x DSR in Mirror's Edge Catalyst and The Division doesn't seem to make much of a difference. The GPU usage on both GPUs is still at about 60%, but the CPU usage did drop a bit.

[aL_eX]

7 minutes ago, stealth80 said:

Also look here, I think you have some bottleneck 1080ti is too damn fast 

 

https://uk.hardware.info/reviews/7270/21/nvidia-geforce-gtx-1080-ti-review-incl-sli-faster-card-for-the-same-price-gtx-1080-ti-slinperformance

 

 

Maybe I should get Rise of The Tomb Raider and test that, it seems like it's the only game that scales really well.

[stealth80]

1 minute ago, aL_eX said:

Maybe I should get Rise of The Tomb Raider and test that, it seems like it's the only game that scales really well.

It's actually a really good game to boot. And a 4K monitor ?

[stealth80]

Stupid question - you using the hbm sli bridge not the motherboard one right?

[aL_eX]

Just now, stealth80 said:

Stupid question - you using the hbm sli bridge not the motherboard one right?

Yeah, it's the Nvida HB Bridge

[PCMasterDebater]

1 hour ago, stealth80 said:

Regardless, psu wouldn't cause the op problems, it would be unstable or shut down. I agree 850w is probably on the low side with regards efficiency for oc x99 and 2x 1080 in sli but it should run it. Remember 1080ti is the fastest gpu and he's using 2 I think this is a utilisation issue 

Agreed, I wouldn't place all the eggs in this basket, but its the best basket to start with.

[Kommanche]

I'm pretty sure this isn't a PSU issue

[aL_eX]

I've found a fix. Disabling G-Sync makes GPU usage go up to 90% - 98% . I also just got the power meter when I found this out (I'm pulling 750W from the wall), so that was a waste of money . 

 

Does anyone know why this might be happening? I would like to continue to use G-Sync if possible.

[aL_eX]

33 minutes ago, PCMasterDebater said:

Agreed, I wouldn't place all the eggs in this basket, but its the best basket to start with.

Please see my post above

[aL_eX]

57 minutes ago, stealth80 said:

Stupid question - you using the hbm sli bridge not the motherboard one right?

Please see my post above

[PCMasterDebater]

11 minutes ago, aL_eX said:

I've found a fix. Disabling G-Sync makes GPU usage go up to 90% - 98% . I also just got the power meter when I found this out (I'm pulling 750W from the wall), so that was a waste of money . 

 

Does anyone know why this might be happening? I would like to continue to use G-Sync if possible.

Don't consider it a waste of money. Wait til you start tweaking things and find yourself pulling more then 750w's for extended periods of time. Ever have a PSU fail on you? I wish it upon no one, it sucks.

 

 

Glad you found the problem. That is after all, the only thing matters.

[NinJake]

What refresh rate is your monitor rated for?

 

If you only have a 60hz monitor, g-sync will only allow you to keep 60fps... which should be a breeze for 1080ti sli.

[aL_eX]

3 minutes ago, NinJake said:

What refresh rate is your monitor rated for?

 

If you only have a 60hz monitor, g-sync will only allow you to keep 60fps... which should be a breeze for 1080ti sli.

Refresh rate is 165Hz, but the framerate never went above that with GSync enabled

[NinJake]

Wow, that's awesome lol. Is it 1080p, 1440p or 3840p?

 

Depending on how many pixels your pushing, like if you have a 1080p monitor and are only playing CS:GO, your gpu(s) won't have to work, like... at all to achieve that 165fps to sync with your refresh rate.

[quan289]

4 hours ago, PCMasterDebater said:

You're not helping the OP with this nonsense, you're confusing him. I'm not going to regurgitate the same shit over and over though when all the information is readily available for him to make the CORRECT choice in this matter. I'm sure he already googled it and realized how wrong you are. 

 

OP, you need a Seasonic, XFX, or Superflower 1000w PSU or greater. Simple as that. Personally, I go with Seasonic.

If you want to argue about what giving him confusion, it's once contradictions of information had been given to him. Someone said it should be enough, then someone said it not. Then someone told the person he calculated wrong because he added the power draw of a entire system twice at AC power draw while adding a power draw of a CPU on top of that (showing a calculated power draw accumulating of 2.5 systems - totaling 837.1W. That point alone shows that the calculated power is well within the 850w capability). Then you decide to come along only making the statement that everybody else is wrong.

 

Multiples of contradictions regarding the PSU without trying to isolate the actual issue that the OP is having to be 100% sure if he should invest a large sum of cash in buying something that he isn't completely sure if is the issue. If I'm confusing him, you are playing a role in that.

 

He has the PSU and powering the system already. His EVGA Supernova 850 P2 is a high quality, high-end PSU that's based on the Super Flower Leadex platform, that's capable of offering good electrical performance in respect to load regulation, line regulation, ripple suppression, and response to transient load. And it could do so while doing a 10% overload at 930wDC continuously as shown here which is understandable because many high-end units are over-engineer to output greater amounts of power than what it is rated (like how the Antec HCP 1200 can output up to 1700wDC while still offering 1% v.reg and 20mVpp ripple suppression. It also have shown to draw up to 2200wAC at the wall - which is around 1700wDC at that load / efficiency).

 

So the OP's issue shouldn't be a stability issue cause by poor electrical performance (which the system would have locked up or crash if it were). A lack of power shouldn't affect performance and cause the GPU usage to drop down in such a manner, as the GPUs does not know that he has a 850w or 1000w, so it isn't doing any sort of compensation to keep the power draw low or whatever. What a lack of power will do, on the other hand, cause a safety mechanism in the PSU to cut power to the system. Meaning he wouldn't be asking about his GPU usage but rather why his computer is off.

 

Googling found me this review with an i7-6850K that's overclocked to 4.3GHz with two Titan X pascal which has a similar power draw to the 1080 Ti that the OP has. It had show in 650wAC power draw at the wall which is inline with my 600wDC estimation I had before, as shown here and this RM1000x review kitguru used (shows an AC power draw of 650w and a DC power draw of 600w. Since Kitguru station in the EU where they used a 230V line, efficiency at that load should be comparable). This shows that a 850w will be enough for such a setup.
 

Of course, I'm aware that his mileage may varied due to manufacturing variances, specific cards he bought, the voltages that the CPU/GPU is set at to maintain his overclock, and what sort of application he is running (using power bug applications that stresses the components 100% simultaneously like Prime95+Furmark). My statement of the 850w should be fine allows him to verify his power draw and act accordingly to that reality (if it turn out that I'm wrong, then by all means replace it). It also allow him to further diagnose his problem thoroughly to see if he can fix his issue (for free) without spending a large sum of money that he doesn't know will work. Your contribution to the thread is tell me I'm wrong and he should spend money when you, yourself, don't know the actual power draw of specific setup, as well as don't know if the PSU is causing his issues in the first place.

[stealth80]

40 minutes ago, aL_eX said:

Please see my post above

 

48 minutes ago, aL_eX said:

I've found a fix. Disabling G-Sync makes GPU usage go up to 90% - 98% . I also just got the power meter when I found this out (I'm pulling 750W from the wall), so that was a waste of money . 

 

Does anyone know why this might be happening? I would like to continue to use G-Sync if possible.

I didn't think 850w PSU was the issue, it's still worth swapping it out for a 1000w though if you can so you aint stressing it as hard. As for Gsync hmm - is vsync enabled in the NV panel?

 

A quick google suggests this isn't an isolated issue. I would say try different drivers but ........ well you cant lol - although I never had any issues with 2x 970's

 

 

[stealth80]

2 minutes ago, quan289 said:

SNIP

Just adding, I never thought it was PSU issue and stated it numerous times throughout

[quan289]

2 hours ago, aL_eX said:

I'm actually starting to think it might be a driver issue. The thing is, my CPU is already overclocked to 4.2GHz, and going any higher would require 1.45V, which I'm not comfortable with using for extended periods of time. Is there a way to uninstall old GPU drivers (I had a GTX 660 prior to the upgrade) or make sure that they are installed correctly?

Yeah, I understand. You could uninstalled it in the Control Panel or Device Manager. There are also third party applications that will thoroughly all traces of the driver like the Display Driver Utility (DDU) here (which I usually used in Safe Mode when switching to Nvidia from AMD and vice versa. You're likely be fine without using, but if you want to be thorough, you can used it if you want ) : http://www.guru3d.com/files-details/display-driver-uninstaller-download.html