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Threadripper 3960X CPU & RAM Overclocking - Results ( might help you with your OC )

Pooh

Pooh

Pooh

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Joined
22 Oct 2006
Posts
1,103
Over the last few days I have been dialling in my CPU and RAM looking for stable 24/7 overclocks at the same time keeping voltages and thermals under control.

The CPU was the easy bit. It's now sitting at 4200MHz at 1.25 V with very nice temps.

The RAM was another matter. Initially I struggled to get it to run anything like stable over it's 3200 stock speed. but many hours or work later and numerous CMOS clearing to reset the C6 Memory Error during POST I managed to get somewhere, eventually getting to run stable at 3400 which I understand is not bad for 128GB of RAM in four 32GB Sticks. With a little success in hand I decided to see how far I could push it, with crazy results.

To make a very long story short I managed to get the RAM stable at 3800 using 19,21,21,21,58,45 timings.

I know it's not all about the highest MHz when it comes to RAM, it's a combination of all the timings so I ran an AIDA64 test on each stable configuration to understand the performance gains or losses.

For stress testing Prime95 was the instrument of choice.

In summary I saw between 12% and almost 15% increase in data throughput.

The results are as below, and I hope that they can be of some help to others. The system details are on the spreadsheet

I have also attached an image of the BIOS power control settings that I used.

Time now for some flight sim fun.





 
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Hard to say just yet. Clocking the RAM is never going to give as much bang for your buck as clocking the CPU but it's good the be able to get the best out of what you've got.

I'm going to start clocking the individual CCXs to see how far I can get it while keeping thermals and volts under control.
 
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I've been messing about with my RAM speeds to see what effect it had on a benchmark I was testing, anyway here is my AIDA64 result running at 3733MHz:

83Pk7Lc.png


The CPU is running at stock.

83Pk7Lc.png
 
What RAM are you using as those timings are very tight compared to mine and how much do you have.

You say the CPU is running at stock but the multiplier is showing as 43.5X

Interested to compare your system to mine

Having done some more studying on the subject I'm now playing with the best combo of FCLK and UCLK as when you go above 3600MHZ the ratio tends to go from 1:1 to 1:2 which gives a big performance hit apparently. There are some reports that you can maintain 1:1 at speeds up to 3733MHz so that's what I'm playing at. I've now set FCLK at 1866 as you get a 2:1 ratio for the RAM speed and manually set UCLK ratio to 1:1 in the BIOS.

I also notice that my FSB drops to 99.8 while yours stays at 100 so I've manually set mine at 100.2 to force it to stay above the 100Mhz mark.

After much more testing I have settled for CPU 4250MHz across all cores at 1.2125V and 3733MHz RAM as per below which did show a performance improvement compared to the 3800MHz setting

Overall a happy camper seeing as how I was struggling to get it over 3200MHz at the beginning of the week.



 
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Looks like you've gone into a lot testing on the RAM front @Pooh , and quite impressive to get your RAM 3800Mhz, even if you settled for 3733 in the end. Seems like you have a much better 3960X than mine. I used to overclock mine but abandoned it, it wasn't stable with AVX loads with 1.275v @4.2Ghz. Just left it to stock, especially as the Noctua can only dissipate so much heat. Your 15k+ flex on CB20 at 4.4 ain't to shabby either, but I guess that's what you get with water.
 
tommoT.Striker said:
Looks like you've gone into a lot testing on the RAM front @Pooh , and quite impressive to get your RAM 3800Mhz, even if you settled for 3733 in the end. Seems like you have a much better 3960X than mine. I used to overclock mine but abandoned it, it wasn't stable with AVX loads with 1.275v @4.2Ghz. Just left it to stock, especially as the Noctua can only dissipate so much heat. Your 15k+ flex on CB20 at 4.4 ain't to shabby either, but I guess that's what you get with water.
Click to expand...

Thanks.

It’s been a bit of a journey but for me part of the enjoyment is figuring out a new system and how to get the best from it. I’ve been an Intel user since my core2duo days having moved there from an Athlon64 many years ago.

Learning a new system is always daunting at the start but the payback when you start to get your head around it is equally rewarding.

It seems like I’ve got myself a good chip and RAM combo. I could probably tweak it some more but I think it’s time to start enjoying the performance.

I’m away for the weekend but when I get back Monday I’m going to rerun the CB20 tests from my other posts with the CPU at 4.425 and 4.3 to see if that improves the scores with the new RAM timings.

I’m also going to drop the RAM voltage back from 1.39 to 1.36 and see if it stays stable.
 
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Pooh said:
What RAM are you using as those timings are very tight compared to mine and how much do you have.

You say the CPU is running at stock but the multiplier is showing as 43.5X

Interested to compare your system to mine

Having done some more studying on the subject I'm now playing with the best combo of FCLK and UCLK as when you go above 3600MHZ the ratio tends to go from 1:1 to 1:2 which gives a big performance hit apparently. There are some reports that you can maintain 1:1 at speeds up to 3733MHz so that's what I'm playing at. I've now set FCLK at 1866 as you get a 2:1 ratio for the RAM speed and manually set UCLK ratio to 1:1 in the BIOS.

I also notice that my FSB drops to 99.8 while yours stays at 100 so I've manually set mine at 100.2 to force it to stay above the 100Mhz mark.

After much more testing I have settled for CPU 4250MHz across all cores at 1.2125V and 3733MHz RAM as per below which did show a performance improvement compared to the 3800MHz setting

Overall a happy camper seeing as how I was struggling to get it over 3200MHz at the beginning of the week.
Click to expand...


My RAM is Corsair: CMK16GX4M2K4133C19 - (32GB) as read from Taiphoon, which wasn't in their database at the time, so I uploaded it a while back now.

Had zero issues cranking up the speed, just changed the respective speed and timings and rebooted, no crashes, errors, BSOD's etc....100% rock solid.

The CPU speed will be reporting to what the clock speed was at the time the bench was run, but its all running at stock.

The infinity fabric is 1:1
 
Thanks for the update.

I’m not sure that would qualify as cranking up the speed as that ram is 4133mhz rated. Why are you running it at 3733 which would be an underclock.

It should be easier to clock with 4 x 8GB sticks than my 4 x 32GB sticks.
 
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To keep the timings a bit tighter and keep it at the optimal IF speed. Could prob try for CL14 but think the gains wouldn't be worth it.

I see your point re. the ram speed, - this kit is fantastic.
 
ketma said:
To keep the timings a bit tighter and keep it at the optimal IF speed. Could prob try for CL14 but think the gains wouldn't be worth it.

I see your point re the ram speed, - this kit is fantastic.
Click to expand...

fair point but you board does support up to 4400MHz. While that does mean you would be on 1:2 ratio it would be interesting to see if you could get your RAM there and if so what the throughput would be like.

would also be interesting to see the numbers at CL15 and CL14 if possible.

at the end of the day you have some nice RAM to play with.
 
Got home a bit early and seeing as how the weather was terrible I had a go at the CB20 tests.

There were some nice improvements from 4250MHz and 4300MHz and a lesser increase from the 4425MHz overclock

Sores as Follows

4250 :- 14207 to 14564
4300 :- 14224 to 14772
4425 :- 15005 to 15127






 
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