Overclock your AMD Epyc

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heavyarms2112

Member
Feb 11, 2022
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anyone unlocked AMD CBS on asrock epycd8-2t board?
It seems this option was available with an engineering sample 7742 processor chip but not with retail 7551p chip.
 

RolloZ170

Well-Known Member
Apr 24, 2016
6,709
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anyone unlocked AMD CBS on asrock epycd8-2t board?
It seems this option was available with an engineering sample 7742 processor chip but not with retail 7551p chip.
seems only the rome BIOS has CBS settings , not the naples part.
 

evolucian911

Member
Jun 24, 2017
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you can't unlock not existing BIOS settings, only hidden ones.
That's sad. I wish I had a menu to OC or change ram speed or timings. Or a way to set that in windows at least. Bought the EPYCD8-2T for the dual 10G among other things but I have some ram with B-Die i used to run at 3200 cl14 on aa TR-Pro build. upgraded that system at work but at home i use a 7351.

I modified a hp dl325 to run dual 8 pin GPU with the cover off and only run at 2400 with said kit. on the epycd8 I get 2666(kit advertised speed) but the CB and CPUz scores didnt change much if any change.

Seperate note... I actually got the asrock stable at 4.1ghz with 1.381v but dialed back since i didnt have proper thermal compound at the time. Should receive krynaught this weekend. Ill send some CB scores. Thats on a Enermax tr4 rev2 360aio...
 

jtaj

Member
Jul 13, 2021
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After all the fun and benefits that I have had from this thread I figured I should post up my build and results.

I think that a 90k on Cinebench is possible if I run the test enough times. The IceGiants are extremely efficient and I can stress test at 3.8ghz without ipmi reporting overheating (both CPU claiming they are under 70c ), however the system will still report overheating and CPU throttling in the server event log, which is unusual as typically I see nothing there when was using less efficient cooling. All attempts at going over 3.8 no matter how much i 'undervolted' it were successful, everytime its an immediate voltage protection reboot.

I did underclock the RAM to the lowest setting in BOIS for the run that got me 89.7k, I had noticed in other OC runs that the DRAM frequency had always dipped slightly on all runs over 3.6ghz. I also set the cTDP to 200 in BIOS, but I doubt this has much effect.

The IceGiants are inpull/push configuration and that means air is flowing over the VRMs as intended, they are 12c - 15c over the CPU temps which rarely go over 70c even in the most agressive sustained OC tests I pushed it through.

ICYMI - i removed the USB header at the bottom of the case as it was obviously shorting ( Sigh ), fortunately I think the Supermicro board has short protection, so I only damaged my pride.

I dont think I would know anyway to push this faster, but if anyone has any ideas I might try it.


View attachment 21568View attachment 21567
LOL thats one heck of a setup. pls share which case and motherboard you're using!
 

Leo Atreides

Member
Dec 23, 2020
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LOL thats one heck of a setup. pls share which case and motherboard you're using!
Sorry for the delay in getting bck to you. The mobo is SuperMicro H11DSi

The case is 5u so as to fit the IceGiants


I didnt get the touchscreen set up yet as I got a contract around about the time I got the case, so didnt finish tweaking the setup.

The case is a bit annoying tbh, there is a VGA connector for the display and a molex power connector. I didnt manage to set up the power circuit correctly the first time as I didnt have anything to connect molex connectors. There is also a usb header for the touch on the disply but I ran out of internal header space for it. I think its a couple of engineering weekends that I dont have available to get the touchscreen working in a nice way.
 
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TXAG26

Active Member
Aug 2, 2016
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Sorry for the delay in getting bck to you. The mobo is SuperMicro H11DSi

The case is 5u so as to fit the IceGiants


I didnt get the touchscreen set up yet as I got a contract around about the time I got the case, so didnt finish tweaking the setup.

The case is a bit annoying tbh, there is a VGA connector for the display and a molex power connector. I didnt manage to set up the power circuit correctly the first time as I didnt have anything to connect molex connectors. There is also a usb header for the touch on the disply but I ran out of internal header space for it. I think its a couple of engineering weekends that I dont have available to get the touchscreen working in a nice way.
That case looks like it might have pretty poor airflow. Looking at the pictures, it’s hard to tell if there is an intake on the front and there are no exhaust fans in the rear. No way that case has enough airflow for a dual CPU MB.
 

Leo Atreides

Member
Dec 23, 2020
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That case looks like it might have pretty poor airflow. Looking at the pictures, it’s hard to tell if there is an intake on the front and there are no exhaust fans in the rear. No way that case has enough airflow for a dual CPU MB.
There are two fans 120mm fans in the front panel that draw from the side vents, and there are on my case there are 2 80mm fans on the back. I changed the front fans to 2x 140mm noctua which draw through th e side vents and the icegaints which pull from front to back work fine.
 
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TXAG26

Active Member
Aug 2, 2016
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There are two fans 120mm fans in the front panel that draw from the side vents, and there are on my case there are 2 80mm fans on the back. I changed the front fans to 2x 140mm noctua which draw through th e side vents and the icegaints which pull from front to back work fine.
Good deal, I must have been looking at the wrong 5U chassis with a front screen.
 

Leo Atreides

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Dec 23, 2020
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jtaj

Member
Jul 13, 2021
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I bought it here, this has more info on the product

have you tried the arctic freezer 4U cpu cooler for TR/eypc? in terms of height its around 153mm I think and its probably the best right after icegiant's

it would also allow you to add more PCIe cards.
 

Leo Atreides

Member
Dec 23, 2020
30
11
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have you tried the arctic freezer 4U cpu cooler for TR/eypc? in terms of height its around 153mm I think and its probably the best right after icegiant's

it would also allow you to add more PCIe cards.
I am not the most experienced hobby builder on the site, those air coolers do look good, but they are not blowing front to back, which is what you want on he Supermicro DS11 boards so you can get some cooling on the VRMs. I have used the noctuas that fit 4u chassis and they were not good enough for overclocking the ES 7742s
 
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jtaj

Member
Jul 13, 2021
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I am not the most experienced hobby builder on the site, those air coolers do look good, but they are not blowing front to back, which is what you want on he Supermicro DS11 boards so you can get some cooling on the VRMs. I have used the noctuas that fit 4u chassis and they were not good enough for overclocking the ES 7742s
you can overclock the milan server CPU? thought its all locked like intel lol
 

RageBone

Active Member
Jul 11, 2017
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what sort of bug?
On Rome ES, the SMU command for "set all core frequency" seems to work with some things to watch out for.
Additionally, setting a low EDC causes the CPU to ignore limits and actually do the set clocks with a negative offset. Both have the downside that you can reliably kill your cpu if you don't watch out.
Everthing is described somewhere on here on sth.
 

Leo Atreides

Member
Dec 23, 2020
30
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you can overclock the milan server CPU? thought its all locked like intel lol
With the IceGiants I have managed to stay at 3.8Ghz long enough to get this


Down to 15th place. I read on the site that there might be better voltage / clock speed pairs.

To learn how to do it you need ExecutableFix's posts https://forums.servethehome.com/index.php?threads/finally-overclocking-epyc-rome-es.28111/

The Icegiants can reliably stay at 3.75Ghz, it draws a lot of power though.
 
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FIIZiK_

New Member
Nov 15, 2022
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If anyone is interested, Rebar can be added to the Supermicro H11DSi-NT Rev2.0, tested with the latest Nvidia Gen, and with 256GB ram, the Bar size is 32GB.

I can also confirm it works with the modded v1.3 bios from Nero, which still works fine on the Rev2.0 of the board.

I modded both the official v2.4 and Nero's modded v1.3 from Nero.
Flash with IPMI. I only tested the v1.3, not 2.4, but it should work without issues as well. Edit: Just tested and 2.4 does not work with rebar.

Once the bios is flashed you need to follow the instructions on Github and use ReBarState with option 32, then restart and voila: GitHub - xCuri0/ReBarUEFI: Resizable BAR for (almost) any PCIe 3.0 system

rebar.jpeg

Edit: Was able to get it to 3.7Ghz at 1.2v for 19200 Cinebench score, watercooled 55Celsius on the cpus and 70C on the VRM with 2 30x10mm fans added to it. In gaming it even works at 4Ghz, but can't keep it stable at 100% usage.
 
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FIIZiK_

New Member
Nov 15, 2022
21
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Anyone has an issue where sometimes the overclock is not applied and it requires multiple restarts for it to be applied?
Anyone found a fix ?