Overclock your AMD Epyc

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ExecutableFix

Active Member
Nov 25, 2019
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Nice. I'm able to get some rome 2 64/128 1.8ghz cpus, these could be a good overclockers then.
Well not really, as I mentioned before it's currently not possible to push above the max boost clock and even if it would be possible there's no board VRM that's going to handle those frequencies long. What's the boost clock of those chips? Never seen 1.8Ghz 64C's
 
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hrvoje.sedlic

New Member
Dec 23, 2019
21
3
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Maximum boost power on all cores is alot, if I'll be able to oc 7742's to 3.0 all core, thats 25% increase, alot in my opinion.

I will send cpuz once recieved from my reseller.
 

Gordan

Member
Nov 18, 2019
39
8
8
Being able to permanently run at full boost clocks would still be really useful. I have 7402P and I cannot maintain full 3.35GHz of boost under load. Under all-core load it drops to about 3150-3200. And it's not the heat, I haven't seen the CPU get above 60C.
 

diogin

Member
Mar 28, 2018
55
15
8
Beijing, China
Being able to permanently run at full boost clocks would still be really useful. I have 7402P and I cannot maintain full 3.35GHz of boost under load. Under all-core load it drops to about 3150-3200. And it's not the heat, I haven't seen the CPU get above 60C.
Have you raised the cTDP to 200W? This may helps as the default TDP of 7402P is 180W
 

hrvoje.sedlic

New Member
Dec 23, 2019
21
3
3
Being able to permanently run at full boost clocks would still be really useful. I have 7402P and I cannot maintain full 3.35GHz of boost under load. Under all-core load it drops to about 3150-3200. And it's not the heat, I haven't seen the CPU get above 60C.
That sounds good. How much better performance in % you get?
 

Gordan

Member
Nov 18, 2019
39
8
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Have you raised the cTDP to 200W? This may helps as the default TDP of 7402P is 180W
I did, both TDP and cTDP, and up to 250W. On the EPYCD8 board going to 200W seems to get me an extra 100MHZ or so of permanent boost. Going higher seems to make no difference. Still 150-200MHz below the maximum 3350MHz boost with a less intensive load.
 

diogin

Member
Mar 28, 2018
55
15
8
Beijing, China
I did, both TDP and cTDP, and up to 250W. On the EPYCD8 board going to 200W seems to get me an extra 100MHZ or so of permanent boost. Going higher seems to make no difference. Still 150-200MHz below the maximum 3350MHz boost with a less intensive load.
Seems like 200W is the hard limit of cTDP, so numbers above 200W is treated as 200W.
The boost frequency is not advertised as all core boost frequency, it usually means frequency for 1-2 core(s). So a drop of 150-200MHz is reasonable.

If someone could manage to unlock the hard limit of cTDP, it may be much easier to overclock :D
 

epyc es001

New Member
Jan 2, 2020
2
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i bought zs1406e2vjug5_22/14_n 64c128t epyc 7742 es sample. its only 400 dollars.
this cpu can be run on krpa u16,ererything was fine just like normal cpu, i have been using it to run premiere pro.
but its base clock is only 1.4 and boost 2.2, aida64 shows its base clock is 22x100=2.2g windows task manager shows 1.4.
this cpu runs cinebench r20 for only 10800 scores due to its low base clock.
if rome can be overclocked, this cpu would be great.
QQ截图20200102195310.png AMD-EPYC-ROME-SiSoftware.jpg QQ截图20200102195300.png
 
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jerrytsao

MILAN X P5800X
Sep 11, 2016
39
31
18
Shanghai, CN
Hello,

Some examples (for Matisse/Rome/CastlePeak)

1. Enable Manual Overclock
Change command to 0x5A and hit Apply. Status should say "OK" and the CPU should be forced to base frequency.
2. Disable Manual Overclock
Change command to 0x5B and hit Apply. Status should say "OK" and the CPU should be back to default.
3. Set Overclock Frequency for all cores
Manual OC should be enabled first (step 1). Change command to 0x5C and Argument 0 to 4000 (or your frequency of choice). Hit Apply. Status should be OK and a dialog with the response should be the frequency in HEX.​
Tested in Rome 7702 + ASRock EPYCD8-2T + SMU Debug Tool v1.1.1, unfortunately typing 0x5A resulted in "Error SMU Write"

 
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Gordan

Member
Nov 18, 2019
39
8
8
Is there a way to change the boost clock vid? The boosting seems to be limited by the cTDP, which something seems to cap at 200W on a 24-core 7402P. So if there is some margin for undervolting, that will reduce the cTDP and it might allow for running higher boost under full load.
 

Gordan

Member
Nov 18, 2019
39
8
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my motherboard is asus krpa u16, actually i dare not to make any changes because its an es cpu.
It shouldn't be a permanent change, this should just write to a register. Worst case, power cycle to get it back to stock. You might stand a better chance with the ES model, as there is a chance the registers arent't locked read-only.
 

68k-dude

Member
Jan 2, 2020
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Gordan

Member
Nov 18, 2019
39
8
8
You can OC 1st gen Epycs that you have using zenstates. It's the 2nd gen Epycs that we are struggling with here.
 

charliehorse55

New Member
Oct 3, 2019
16
2
3
Are there programs available to do in-OS overclocking on threadripper 3? The 1st gen epycs had the exact same OC registers as threadripper 2, correct? It would just be a matter of checking to see if the equivalent registers on rome are unlocked.
 

ExecutableFix

Active Member
Nov 25, 2019
123
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28
Are there programs available to do in-OS overclocking on threadripper 3? The 1st gen epycs had the exact same OC registers as threadripper 2, correct? It would just be a matter of checking to see if the equivalent registers on rome are unlocked.
Yea just ZenStates all-core overclock :)
 

Gordan

Member
Nov 18, 2019
39
8
8
Zenstates tools don't work on Time. BIOS OC settings on EPYCD8 board don't work on Rome.