Potential performance/unoptimised issue

bignev72

bignev72

bignev72

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22 Mar 2012
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Hi Guys,

I built a PC about 1.5 years ago and I've always felt that I should be getting higher FPS in games due to the fact I have a RTX 3090. Performance has always been good but there's just this niggling feeling it should be better. It started with CP2077 where I was getting 20FPS on max settings without the use of DLSS but I accepted that the game was very demanding and enabled DLSS. Since then I've had to use DLSS in several games (Metro Exodus, Dying Light 2 etc) to get 50-60fps at maximum settings. But again I put it down to Raytracing being such a killer.

I play at 5120 x 1440 resolution and have a 5800x, RTX 3090, 4000MHZ RAM and a 750w PSU. A lot of my worry is that the PSU is underpowered and the RAM is not running at the CPU infinity fabric. However underclocking the RAM to 3600MHZ seems to make no real difference in my FPS in games. I've checked YouTube videos for game performance 4K benchmarks in the past and my performance is similar so have largely put off doing anything about it. I've always thought that perhaps I'm expecting too much.

What's kicked this off again is that my friend has recently bought a 3080ti. He has a 10850k CPU and games at the same resolution as me so we should be getting similar performance in games. He is getting 120FPS on Tiny Tina's Wonderland on Ultra and I'm getting 70-80FPS at Ultra. Obviously this is a new game so won't be well optimised and I'm taking my friends word that his settings are the same as mine so this could be nothing. However the disparity in performance does seem quite large.

I ran a benchmark on TTW with RAM @4000MHZ and @3600MHZ and there was 1FPS difference between the FPS average. All other settings were the same. So I don't know how much difference RAM speed being in sync with infinity fabric makes?.

I can't find anything which shows total system power draw. However I had GPU-Z running in the background while running the benchmarks and I can see the following peaks - Board Draw (350w), GPU chip Draw (185w), MVDDC Power Draw (115) and PWR_SRC Power Draw (125w). Those all add up to 775w which is higher than my PSU supports. So I'm thinking that my issue is probably my PSU. I do see perflimit pwr shown at certain points in both GPU-Z and HWiNFO when gaming. However my understanding is that this is due to the GPU reaching it's allocated power limit rather than the system not providing it enough power.

Sorry I realise the above is meandering so basically in summary what I'm asking is;

Is there anyway to prove that my PSU is limiting my gaming performance?

How much difference does RAM speed / IF being in sync make?

What else can I check or do to improve or better understand whether my performance is normal?


*Update with more info*

My PSU is a Corsair RMx 750W so it's not a really cheap PSU brand or anything.

I have previously checked CPU / GPU temps as well as GPU Memory temps and these have always been ok. But I will run some tests and get some figures to bring back here.
 
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bignev72 said:
Is there anyway to prove that my PSU is limiting my gaming performance?
Click to expand...

It's not your PSU.

Have you run Afterburner with stats enabled to see what sort of % utilisation your GPU is at while playing a game? If not download it, and run heaven benchmark for a while, and CP2077, note the GPU usage, and the clock speeds, see where they peak and where they settle after 30-60 mins.
 
You do not mention the brand or the particular psu you are using. It is best to have some headroom with a psu but almost all of them are good for at least 10% over their stated wattage so I would be surprised if you are limiting performance in that way.I am also not sure that is how power draw with a psu works at all, my understanding is that the pc will draw the wattage it needs and if your psu is overloaded for its specs it will shut down , Over voltage protection or something similar.

You are playing at a very high resolution so the vast majority of stress is placed upon the gpu and cpu+ram are far less important. The best way to check if you are getting the expected performance is to run 3Dmark, or another gpu benchmark, and compare your score with other similar systems.

Potential problems to look for. 3090 has memory modules on the back and they can get hot. If they are overheating it will limit the performance of the entire card so you need to loop a benchmark and monitor gpu memory temps to see if you have an issue.
 
bignev72 said:
Board Draw (350w), GPU chip Draw (185w), MVDDC Power Draw (115) and PWR_SRC Power Draw (125w). Those all add up to 775w which is higher than my PSU supports
Click to expand...
no these do not add up, these are breakdown of the first item by source and consumer
GPU will draw 350w with transient spikes to 400-450w.
Insufficient PSU would manifest as crashing and reboots in high power situations.

PSU is not your problem

bignev72 said:
I ran a benchmark on TTW with RAM @4000MHZ and @3600MHZ and there was 1FPS difference between the FPS average
Click to expand...
Still recommend running RAM in sync with IF. It will give a slight improvement for CPU limited stuff, maybe 1% lows.
But there is probably even more to gain by tuning timings manually.
To get an idea if CPU or RAM is ever the limiting factor, check how often GPU utilisation is below 99%.

RAM is not your problem, not at that high resolution and settings

bignev72 said:
He is getting 120FPS on Tiny Tina's Wonderland on Ultra and I'm getting 70-80FPS at Ultra.
Click to expand...
This is a huge gap, hard to even imagine what could cause this.
There must be something really different between the two.
CPU? Should be in your favour.
Cooling? Could your GPU be downclocking from insufficient cooling? I heard memory on GPU backside is often overheating on 3090? Although yours is custom MSI...
Settings? Are you sure its the same settings? Something like forced heavy antialiasing would result in a hit that big.
Something silly like single channel RAM - in wrong slots?

Need to monitor what clocks and utilisation the GPU is running in games to know more.
 
OP's PC is similar to mine except I have a 5900X and (although I don't think its relevant) a 1600W PSU.
I couldn't get my CPU IF to reach 2000MHz for my 4000MHz memory and not 1900MHz either so I left it in AUTO and it chooses 1800MHz.
I recently had a BIOS issue so for a few days I had the memory on non-XMP (2333MHz I think). This did not affect FPS.
I leave my G9 Neo set to 120Hz and all my games play fine - occasionally I check it and generally I don't see it below 120FPS.
However most of my games are less taxing - I think the only time I saw less than 120FPS was with a game called Outriders.
What about GPU temperature? One thing that is guaranteed to reduce FPS is if the GPU starts to throttle.
 
alec said:
Cooling? Could your GPU be downclocking from insufficient cooling? I heard memory on GPU backside is often overheating on 3090? Although yours is custom MSI...
Settings? Are you sure its the same settings? Something like forced heavy antialiasing would result in a hit that big.
Something silly like single channel RAM - in wrong slots?
Click to expand...

I have checked GPU memory temps before and they went to 88C at the maximum from what I can remember. My understanding is that 110C is the temp at which they overheat. But I will do some more testing on this.

The motherboard manual says the RAM has to be in slots A2 and B2 if you have two RAM sticks. I've just double checked and that's where the RAM is.
 
A quick update for everyone. I went through all the in-game settings with my friend and they match. He even sent me a screenshot with 120fps showed.

However I have looked at some benchmarking videos of TTW on youtube and it seems like everyone else is getting the same performance that I am, with similar hardware. So I think my friend has some sort of special once in a lifetime setup where everything comes together perfectly.

I might try and raise my infinity fabric on my CPU and see what kind of difference that makes.

Thanks for your help.
 
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