Low 4090 performance in a prebuilt, how to improve?

[dlin95123]

Glad it was somthing so simple it's off by default so I didn't even think of it.

The default on mine is on, probably due to the Studio Driver I use. My work is more similar to rendering than gaming, I suppose.

 

[Deleted member 223428]

The default on mine is on, probably due to the Studio Driver I use. My work is more similar to rendering than gaming, I suppose.

Ahhhh...

I've always been curious how much using ECC affects performance, and now I know. I learned something today.

 

[oxrufiioxo]

The default on mine is on, probably due to the Studio Driver I use. My work is more similar to rendering than gaming, I suppose.

Makes sense. Glad it was a big nothingburger.

Ahhhh...

I've always been curious how much using ECC affects performance, and now I know. I learned something today.

Same.

 

[dlin95123]

Now should I get a larger AIO for my 13900K? It has a 240mm AIO with 2 fans? The case is too short for a 360mm. But will a 280mm AIO help? Currently, I have to limit the PL1 at 230W and PL2 at 180 watts to keep it from thermal throttling.

But guess this topic belongs to another forum group.

Thanks all again.

 

[Belfaborac]

What kind of CPU temps do you see?

A 280mm radiator will give you ~30% more area than a 240mm and just shy of the area of a 360mm. In other words, if you actually need an upgrade a 280 will be just about as good as a 360. And if you do change, get one with a radiator that's thicker than the typical 25mm if you can.

 

[dlin95123]

What kind of CPU temps do you see?

A 280mm radiator will give you ~30% more area than a 240mm and just shy of the area of a 360mm. In other words, if you actually need an upgrade a 280 will be just about as good as a 360. And if you do change, get one with a radiator that's thicker than the typical 25mm if you can.

I get a max core temp of 88-90C. This is with setting the PL1=180watts.

 

[Belfaborac]

Well, it's within spec, but higher than I would like to see over time personally. Chances are it'll be just fine, but if it was me and the work being done on it was important (which it sounds like it is) then I'd get a beefier cooling solution. In the 280mm bracket the Arctic Liquid Freezer II 280 appears to rule the roost, both at Tom's Hardware and several other places. At 38mm it's uncommonly fat, which is a very good thing, and I believe it can be had both with (NO!) and without (YES!) RGB.

 

[Calenhad]

I would suggest that you just start using the computer before worrying about cooling. That CPU will run hot when under max load. But 90C is within spec and the boost frequency seems to be fine as well. No point tinkering unnecessarily with a new computer imho.

 

[oiawshboiwsahnoidaws]

Glad it is working as intended
Not sure how much you like to tinker with your PC but undervolting the cpu can increase efficiency by a decent amount; +15% for my 12700k (every cpu is different! "silicon lottery")
There are multiple ways to go about it, one simple way would be in your bios under DigitAll Power lowering the CPU Loadline Calibration to Mode 3, 4, 5 or lower till Vcore/cpu core voltage is lowered under load compared to auto/default
Will take some trial and error (and crashes lol) to find a good undervolt that works in all workloads tho

 

[dlin95123]

I would suggest that you just start using the computer before worrying about cooling. That CPU will run hot when under max load. But 90C is within spec and the boost frequency seems to be fine as well. No point tinkering unnecessarily with a new computer imho.

Good advice. I should probably not modifying hardware at this time. Instead, I think I should learn more about the basics of BIOS. A reason that the thermal is not exceeding 90C is that I set the long term max power to 180 watts. This seems to be low for a i9-13900K CPU.

Glad it is working as intended
Not sure how much you like to tinker with your PC but undervolting the cpu can increase efficiency by a decent amount; +15% for my 12700k (every cpu is different! "silicon lottery")
There are multiple ways to go about it, one simple way would be in your bios under DigitAll Power lowering the CPU Loadline Calibration to Mode 3 or lower (Doing that will lower Vcore/cpu core voltage under load)
Will take some trial and error (and crashes lol) to find a good undervolt that works in all workloads tho

How is the +15% measured?

I am thinking to increase the long term max power to 200 watts and then lower the CPU loadline calibration. Should I try one at a time or both at the same time?

 

[oiawshboiwsahnoidaws]

It's fine to do both, i have my power limit set to 150W
This is CPU-Z benchmark with default loadline:

And this one is with Loadline mode 3:

Close to 15% higher multi thread score with same power consumption
Note how far the Vcore drops with loadline mode 3 compared to my boards default loadline

Btw when overclocking or undervolting a cpu i can recommend y-cruncher to test for system stability
Running y-cruncher for a few minutes will tell a lot if the system is stable or not
Can also be used to benchmark and test for stability with a command like this: y-cruncher.exe bench 5b -od:0

 

[dlin95123]

I used Loadline mode 3 and increased the long term max power limit to 200w. With Cinebench R23, I saw thermal throttling within 2 minutes. At what core temp does it throttle?

Update: I used CPU Lite Load instead. I dialed it down from default of 9 to 7. With PL1=200w, it does not thermal throttle anymore! The CPU temp stayed at 81C most of the time during the R23 10 minute test.

Why do I need another test tool like y-cruncher when R23 stresses the CPU at 100% already?

 

[oiawshboiwsahnoidaws]

Throttling should happen at 100°C according to intel spec and most motherboards should be set at that, limit can be changed to above 100°C but i wouldn't recommend that
Cool never used the CPU lite load feature... maybe i should give that a try too
Yeah R23 stresses the cpu fine but different programs/algorithms use the cpu differently (cpu can be at 100% load but with different parts of the cpu etc.) and so its possible that the cpu is stable with one program but not with another, so i often use multiple programs to check for stability after i've done any overclock/undervolt and cinebench and y-cruncher are my favorite

 

[dlin95123]

Strange that it already showed thermal throttling when a core hit 90C, as shown in the first diagram on post #62.

I further lowered the CPU Lite Load to 6. The max temp dropped a bit too. I used y-cruncher with the flags you specified above. It did not crash.

Is there any downside to this level of under-volt?

 

[oiawshboiwsahnoidaws]

Nope as long as everything is stable there should be no downside
But i never used CPU lite load, make sure to benchmark single and multi-thread performance and compare it to no undervolt, there should be no performance loss
Also just wanna mention yet another undervolting method and that is setting cpu voltage mode to Adaptive + Offset and apply a negative offset of like 0.05V or more (not sure how low the average 13900k can go)
edit: well i just tried intel's overclocking software and damn didn't know you could undervolt with it (still im oldschool and bios is my thing not some fancy software haha... but it does seem useful)

edit2: found a good short video about why and how to undervolt:

 

[Bobaganoosh]

As others have mentioned, the liquid freezer ii 280 is a great AIO, and they also mentioned the fat radiator, but I just wanted to point to that fact and let you know to make sure you have room for that thicker radiator before buying it. It will make the fans mount lower in the system (closer to the motherboard) and not every case has room for that. In some cases you can lower the motherboard, but not all of them. Also, I wouldn't put that AIO on the front as it will then put that hot air into the system, raising the ambient temperatures of your GPU, VRM, memory, etc. It's often not a deal-breaker to do that, but if your main use is putting the GPU under load, you want fresh air going to it as much as possible, so it's ideal to have that radiator as an exhaust in the top.

That said, the approach you've taken above seems to be good. I was going to suggest you can probably get away with an increase in PL1 and then do a slight voltage offset and gain performance without losing much in terms of temperatures, but it looks like you're there.

The Intel XTU app is helpful for doing some tuning within Windows, but I prefer to do my tuning in the BIOS. Sometimes it's helpful to find what works with the app then go back and try to run it in BIOS once you have those numbers figured out. the XTU settings only stick if you're running that at start-up. It would then apply those settings every time you boot the PC. This is normally fine, but I always prefer less background apps whenever possible, and if it's actually stable, it'll be stable if applied from BIOS.

 

[dlin95123]

I think I am done with the performance tuning of my PC. Thanks again to everyone who has chimed in to help. My current setting is PL1=230w, PL2=253w, and Tau=56s. I use CPU Lite Load to under volt the CPU and set it at 5. I have stress tested it with a few tools and it has been stable. The max max core temp is in the 80s with CB R23 10 minute MC test, and it has a score of 37000 when I set Windows 11 Pro in its "best power efficiency" mode. The 8 P-core's frequency is between 5.2GHz and 5.5GHz during the stress test. For some reason, "best power efficiency" mode yields the highest CB R23 10-min MC score.

This prebuilt PC now is better than the one I received from Corsair 3.5 months ago!