How does clock speed and voltage affects render time in offline multi-thread render engines?

[ojito]

I'm having trouble with high temps on a 7950x build. I read somewhere that it's supposed to run at 95° but don't like it very much. I was wondering how under-volting and under-clocking can affect a multi-thread process. Will my renders take longer? I'll be happy to loose 10% performance if that means I can take my temperatures down to 60° on full load. My cpu runs by default at 5300 all cores all day but with those nasty spikes of +95°C. Also how does RAM speed can affect the same kind of workflow.

If there's no problem with underclocking and undervolting my cpu for rendering, should I have a different profile for gaming with high clock speed?

I work mainly with the V-Ray render engine.

Whole build is as follows:
-7950x
-Aorus Master x670E
-128Gb corsair dominator 6000mhz (3600mhz really please help with this as well if possible )
-Liquid Freezer ii 360
-Corsair 5000x case (without front and top glass)
-P12Max arctic fans x7
-4080 tuf oc
-Corsair rm1200x

 

[Chuk_Chuk]

I'm having trouble with high temps on a 7950x build. I read somewhere that it's supposed to run at 95° but don't like it very much. I was wondering how under-volting and under-clocking can affect a multi-thread process. Will my renders take longer? I'll be happy to loose 10% performance if that means I can take my temperatures down to 60° on full load. My cpu runs by default at 5300 all cores all day but with those nasty spikes of +95°C. Also how does RAM speed can affect the same kind of workflow.

If there's no problem with underclocking and undervolting my cpu for rendering, should I have a different profile for gaming with high clock speed?

I work mainly with the V-Ray render engine.

Whole build is as follows:
-7950x
-Aorus Master x670E
-128Gb corsair dominator 6000mhz (3600mhz really please help with this as well if possible )
-Liquid Freezer ii 360
-Corsair 5000x case (without front and top glass)
-P12Max arctic fans x7
-4080 tuf oc
-Corsair rm1200x

Render times relate to your clock speed. Lower clock speeds will result in a longer render time.

You may need to experiment to figure out how much of an increase in render times you may see.

As for different profiles for gaming vs rendering. That is completely up to you. If you need the extra performance while gaming then you can different profiles. I think you can do this with Ryzen master.

Ram speed on render times is not something I have seen tested but in theory it should have a noticeable affect. Your CPU will constantly be calling for data in RAM. So theoretically the quicker your CPU can get that data the sooner it can process it. However don’t forget stability is more. Important.

 

[Brizzles]

Curve Optimiser might help a little with the temps ( you reduce the voltage per core whilst keeping the boost clocks ), BUT it can take a lot of fine tuning especially on a 16 core.

128gb @ 6000 mhz - running 4 x 32gb at 6000mhz is going to be very doubtful - you might get 5600 / 5200 / 4800mhz ( thats dependant on your ram sticks and board- it will vary from kit to kit )

Your cooling is good and you won't better what you have by anything meaningful.

The 7000 series are 'hot' and 95 degrees is the safe limit for a 7950x , my 7800X3D will go 80+ degrees ( same cooler as yours ), the days of 60 degrees being hot are gone

 

[Tetras]

You might want to read this:

A Lighter Touch: Exploring CPU Power Scaling On Core i9-13900K and Ryzen 9 7950X

www.anandtech.com

and watch this:

AMD Ryzen Eco Mode Deep-Dive & Benchmarks on R9 7950X (Zen 4)

Sponsor: Montech Sky One Lite on Amazon https://geni.us/sux2AMD Ryzen 7000 CPUs on Zen 4, including the R7 7700X, R5 7600X, R9 7900X, and Ryzen 9 7950X, have...

www.youtube.com

 

[ojito]

Render times relate to your clock speed. Lower clock speeds will result in a longer render time.

You may need to experiment to figure out how much of an increase in render times you may see.

As for different profiles for gaming vs rendering. That is completely up to you. If you need the extra performance while gaming then you can different profiles. I think you can do this with Ryzen master.

Ram speed on render times is not something I have seen tested but in theory it should have a noticeable affect. Your CPU will constantly be calling for data in RAM. So theoretically the quicker your CPU can get that data the sooner it can process it. However don’t forget stability is more. Important.

Thanks a lot for the brief and the reply, ill try then to maintain as much clock speed as possible while avoiding 95C, i think i can run it at 5200 under 80C without risking crashes. as for the memory i been trying but can't get pass 3600 with all 128gb installed (i need it all). with two sticks only i can run stable at 6000, its a shame really i could have saved money on slower sticks.
Thanks again i have a better idea of what to look for now, ill create a scene that should render in about 30 mins to use as benchmark and will max out volt and clocks up to 80C.

 

[ojito]

POB with curve optimizer is a pain, but i think im close to get it right, one entire ccd runs over 5800 and the other is *slower* with max of up to 5600, two very different parts but at least this mobo has per ccx manual oc, im trying to combine pob with manual using gigabyte's oc tools at least the voltage allocation with the curve isn't too difficult for the ccd's diferences. as for ram i can't get all 128gb to run over 3600. i get into windows at 3800 but crashes on render time. two sticks only if i wan't to run them at 6000
Thanks for you reply, im getting an idea of what to look for when overclocking for render.

 

[ojito]

You might want to read this:

A Lighter Touch: Exploring CPU Power Scaling On Core i9-13900K and Ryzen 9 7950X

www.anandtech.com

and watch this:

AMD Ryzen Eco Mode Deep-Dive & Benchmarks on R9 7950X (Zen 4)

Sponsor: Montech Sky One Lite on Amazon https://geni.us/sux2AMD Ryzen 7000 CPUs on Zen 4, including the R7 7700X, R5 7600X, R9 7900X, and Ryzen 9 7950X, have...

www.youtube.com

will do, thanks

 

[ojito]

Curve Optimiser might help a little with the temps ( you reduce the voltage per core whilst keeping the boost clocks ), BUT it can take a lot of fine tuning especially on a 16 core.

128gb @ 6000 mhz - running 4 x 32gb at 6000mhz is going to be very doubtful - you might get 5600 / 5200 / 4800mhz ( thats dependant on your ram sticks and board- it will vary from kit to kit )

Your cooling is good and you won't better what you have by anything meaningful.

The 7000 series are 'hot' and 95 degrees is the safe limit for a 7950x , my 7800X3D will go 80+ degrees ( same cooler as yours ), the days of 60 degrees being hot are

POB with curve optimizer is a pain, but i think im close to get it right, one entire ccd runs over 5800 and the other is *slower* with max of up to 5600, two very different parts but at least this mobo has per ccx manual oc, im trying to combine pob with manual using gigabyte's oc tools at least the voltage allocation with the curve isn't too difficult for the ccd's diferences. as for ram i can't get all 128gb to run over 3600. i get into windows at 3800 but crashes on render time. two sticks only if i wan't to run them at 6000
Thanks for you reply, im getting an idea of what to look for when overclocking for render.

 

[Mcnumpty2323]

That's modern cpus for you sadly
Really pushing the limits of silicon
The 5xxx series you can control the temperature
To a reasonable level but 7xxx really go high c
Playing around with curve optimiser may help
But it's pretty time consuming if
You want to do it to each individual core
I tried with my 5950x just out of curiosity
And what was totally stable at full load would
Randomly crash the pc under light/idle loads

Another thing you could try
Play with the PPT EDC TDC limits
Doing mine that way has proved more stable

Built a lower end 7xxx recently
Even with an artic 360mm AIO
Seeing 80c was bad enough to me
95c I would hate seeing even if the chips rated for 95c
That's seriously hot

Edit
Make sure your SOC voltage is at a safe level
It does affect the ram
But as we saw recently too high a SOC voltage
Is seriously bad
If you have latest bios it's probably limited
To 1.3v anyway

 

[snarloas1982]

Does the bios not have a temperature limit for the CPU? I can set specific max temps with the i9/Hero setup if I needed it.

 

[Mcnumpty2323]

Does the bios not have a temperature limit for the CPU? I can set specific max temps with the i9/Hero setup if I needed it.

It might do not a bad question
But never looked at mine
Since mines only 5950x and full custom loop
Never needed to
But if it does it may get over enthusiastic
And drop too much performance
Sort of the opposite of auto overclock
Where it gets a bit enthusiastic with voltage
Manually tuning would be my preference

 

[Tetras]

as for ram i can't get all 128gb to run over 3600. i get into windows at 3800 but crashes on render time. two sticks only if i wan't to run them at 6000

This appears to be normal, unfortunately:

Is 128GB of DDR5 IMPOSSIBLE on AM5? Level1 Investigates!

Check out the forum thread here: https://forum.level1techs.com/t/7950x-i-want-4x32gb-unless-it-sucks-does-it-suck/189825**********************************Che...

www.youtube.com

I thought future BIOS updates might address it.

 

[Meddling-Monk]

128GB above 3600 is possible, I'm rocking 4000 (2000Mhz, 1T and 36CL, 2000Mhz Infinity Fabric for 1:1:1) right now. It's just there's a threshold that it won't go beyond, and what the threshold is limited by, is currently not known. But suspected to the the IMC, the RAM (since some RAM simply won't want to play nice) and voltages (which might be harder to do with the SOC limitation of 1.3v now). BIOS updates might help with compatibility, especially with larger modules down the line, but overall it probably won't allow you to run all banks fully stacked at full speeds.

Unless if your software is going to be able to make use of that memory speed increase, I'm not certain that you'll see a major difference over say keeping the CPU at 5Ghz or more instead of 4.5Ghz anyway.

As for a major difference regarding renders and temps (by association of faster renders puts more stress onto CPU and more power used produces more heat). The first thing I'd do is do a benchmark of your system at default speeds and settings first to get a base line. Then try the CPU at Eco Mode 105, and then Eco Mode 65. Then stack on the Curve Optimisers as well. You'll likely find that at Eco Mode 105, you'll retain most of your performance at lower power draw and heat produced. Eco Mode 65 is not really recommended unless if you are trying really hard to keep temps low (living in the desert) - but past experienced puts it at around 65% odd of the normal mode performance and temps hardly breached 55-60C.

 

[Quartz]

Edit: what @Tetras said.

 

[OliverQueen]

Thanks a lot for the brief and the reply, ill try then to maintain as much clock speed as possible while avoiding 95C, i think i can run it at 5200 under 80C without risking crashes. as for the memory i been trying but can't get pass 3600 with all 128gb installed (i need it all). with two sticks only i can run stable at 6000, its a shame really i could have saved money on slower sticks.
Thanks again i have a better idea of what to look for now, ill create a scene that should render in about 30 mins to use as benchmark and will max out volt and clocks up to 80C.

It is widely known that if running 4 sticks of RAM on AM5 that EXPO is not going to work properly & if it does work, it isn't going to be fully stable (not until AMD sort it out with the memory controller). 2 sticks though seem to be fine with QVL certified AMD EXPO modules & will run at higher speed rating of the module all day long. Most find they can get a small manual overclock after some tweaking of the timings/voltage but everyone's mileage varies with fully populated RAM slots. I personally prefer to have a stable system & drop a few percent of performance if need to have as much RAM as can fit onto the board than live on the edge (& potentially lose money from work taking longer to complete due to strange glitches or crashing).

 

[ojito]

This appears to be normal, unfortunately:

Is 128GB of DDR5 IMPOSSIBLE on AM5? Level1 Investigates!

Check out the forum thread here: https://forum.level1techs.com/t/7950x-i-want-4x32gb-unless-it-sucks-does-it-suck/189825**********************************Che...

www.youtube.com

I thought future BIOS updates might address it.

Thanku, will look into this. Ram speed is hard to tune with all slots on use

 

[ojito]

128GB above 3600 is possible, I'm rocking 4000 (2000Mhz, 1T and 36CL, 2000Mhz Infinity Fabric for 1:1:1) right now. It's just there's a threshold that it won't go beyond, and what the threshold is limited by, is currently not known. But suspected to the the IMC, the RAM (since some RAM simply won't want to play nice) and voltages (which might be harder to do with the SOC limitation of 1.3v now). BIOS updates might help with compatibility, especially with larger modules down the line, but overall it probably won't allow you to run all banks fully stacked at full speeds.

Unless if your software is going to be able to make use of that memory speed increase, I'm not certain that you'll see a major difference over say keeping the CPU at 5Ghz or more instead of 4.5Ghz anyway.

As for a major difference regarding renders and temps (by association of faster renders puts more stress onto CPU and more power used produces more heat). The first thing I'd do is do a benchmark of your system at default speeds and settings first to get a base line. Then try the CPU at Eco Mode 105, and then Eco Mode 65. Then stack on the Curve Optimisers as well. You'll likely find that at Eco Mode 105, you'll retain most of your performance at lower power draw and heat produced. Eco Mode 65 is not really recommended unless if you are trying really hard to keep temps low (living in the desert) - but past experienced puts it at around 65% odd of the normal mode performance and temps hardly breached 55-60C.

Thanks for such detailed explanation, I will try this route of benchmarking and troubleshooting to check for improvements.