Overheating problems with 2x Epyc 7742 in Define 7 XL 1TB/2TB RAM

T_Minus

Build. Break. Fix. Repeat
Feb 15, 2015
7,036
1,581
113
CA
Rosewill Rackmount .. no.. no. That's not a real server chassis it's a home-version of a real server chassis.
Do I have experience with them, yes I have 3 various model Rosewill 4U and I don't use them beyond basic storage because they're basically a home variant of a real server chassis ;) that still come with minimal air flow even with better 120 home-style fans.

You do NOT need a rack. You can sit it on a desk, on wood raised off the floor (just no carpet if low), etc...

Your motherboard is only E-ATX nothing special-size or anything like that so you can fit it in many chassis.
I would buy the one SuperMicro suggests for that motherboard and they even sell it as a kit. It's also a 4U \ Workstation hybrid.


You get power supplies made for your motherboard, airflow made for it, etc, etc...

" 3x Middle 8cm (9400 rpm) PWM Fans & 2x 8cm (9400 rpm) PWM Fans "

If you're running this beast at near full utilization it's going to be LOUD.


I'll also be the person who says for such a badass build I would have run 1.5TB Intel Optane Drives, they're PCIE already no adapter needed, won't throttle like m.2 unless you need the space you have from the 3 decent drives you could run 2x 1.5TB 905P Optane and absolutely smoke the performance of your other drives.
 
Last edited:
  • Like
Reactions: gabe-a and i386

Dreece

int 21h
Having been round the block with custom 'power' workstation builds for nearly 40 years now, all I'll say here is I'm loving this thread! :)
Giggling a fair bit here, let us throw 4 turbos into an engine bay designed for a 1200cc engine while we're at it hey?! oh dont worry, just add more air flow, lol, it doesnt quite work that way, it is the design of the case which is the most crucial part for a board that is engineered to be air cooled a certain way.

On a more serious note, it's a stonking piece of tech there, very very nice! If I were going to do a workstation build with that tech, I personally would have popped into a milling shop and shored-up for a custom block for the board for a multi-pump water loop plumbed into an external rad arrangement, a few colleagues have done that with server boards over the years, I only did it the once years ago, never again (silly money). Indeed quiet and cool isn't impossible, the budget is the enabler/disabler. What you desire is not impossible, but the the way you're going about it is just going to keep causing you grief sir.

On a budget? rack it my friend, but don't expect quiet, ain't happening with that setup on air. Rack it in another room, run a usb extension to your desk along with display cables and whatnot and call it a day, enjoy raw power in peace and quiet at your desk. I kind of did the same thing for my other half's and kid's workstations, everything sits in the rack in the attic.
 

i386

Well-Known Member
Mar 18, 2016
2,037
536
113
31
Germany
Rosewill Rackmount .. no.. no. That's not a real server chassis it's a home-version of a real server chassis.
Do I have experience with them, yes I have 3 various model Rosewill 4U and I don't use them beyond basic storage because they're basically a home variant of a real server chassis ;) that still come with minimal air flow even with better 120 home-style fans.

You do NOT need a rack. You can sit it on a desk, on wood raised off the floor (just no carpet if low), etc...

Your motherboard is only E-ATX nothing special-size or anything like that so you can fit it in many chassis.
I would buy the one SuperMicro suggests for that motherboard and they even sell it as a kit. It's also a 4U \ Workstation hybrid.


You get power supplies made for your motherboard, airflow made for it, etc, etc...

" 3x Middle 8cm (9400 rpm) PWM Fans & 2x 8cm (9400 rpm) PWM Fans "

If you're running this beast at near full utilization it's going to be LOUD.


I'll also be the person who says for such a badass build I would have run 1.5TB Intel Optane Drives, they're PCIE already no adapter needed, won't throttle like m.2 unless you need the space you have from the 3 decent drives you could run 2x 1.5TB 905P Optane and absolutely smoke the performance of your other drives.
The 745bac is a great chassis :cool:
 

Dreece

int 21h
z4cxoqffdxq51.jpg

@gabe-a - you'll end up with something like this, honestly with the cheap prices of 4u rack cases and small racks, you can't argue, if you shop with beady eyes you could probably even find a whole setup where you just rip out the board and throw your gear in ;)

Definitely go with 4U so you can throw in large fans that push more air in the right direction with less noise. If done right, you could get away with a setup you can have at your desk, won't be dead quiet, but on idle/regular use ambient around 20c it will be like a low-tone breeze in the background... but do expect things to go crazy when you start pushing that tech into the next dimension of performance (whence my suggestion of racking it in another room if at all possible or do a me and throw it in the attic/basement/garage)
 

msg7086

Active Member
May 2, 2017
256
69
28
33
A bit off topic here.

I'm wondering, if you are doing HPC related work, would it be easier to build multiple single socket workstations and run it distributed? Sorry if this sounds dumb as I'm not familiar with HPC stuff, but I'm thinking that maybe multiple single socket EPYC workstation with regular RDIMM could be more cost effective?
 

Dreece

int 21h
I'm wondering, if you are doing HPC related work, would it be easier to build multiple single socket workstations and run it distributed? Sorry if this sounds dumb as I'm not familiar with HPC stuff, but I'm thinking that maybe multiple single socket EPYC workstation with regular RDIMM could be more cost effective?
Cost/power/noise/space... devil's in the detail I guess. If it's being done at home, it's being done with an all-in-one view, usually the case. The fact the chap went the server-parts route for this in a Fractal case, already kind of shines the light on it being a budget'd setup... distributed setups can very quickly jump into the tens of thousands.
 

Stevecam

New Member
Oct 1, 2020
4
2
3
33
I noticed a few caps were placed behind the board, would airflow back here be helpful?
 

gabe-a

New Member
Sep 10, 2020
24
3
3
Cost/power/noise/space... devil's in the detail I guess. If it's being done at home, it's being done with an all-in-one view, usually the case. The fact the chap went the server-parts route for this in a Fractal case, already kind of shines the light on it being a budget'd setup... distributed setups can very quickly jump into the tens of thousands.
Hehe, funny you should mention this. The reality is, I paid multiple tens of thousands of my own savings for a company to build this for me. This Fractal business is their rebuild. The first was in a glass case and literally wouldn't boot without an alarm. After so much sunk cost, I am willing to almost do anything at this point. (Almost = I have no skills myself with hardware, having not even built a normal desktop on my own).
I noticed a few caps were placed behind the board, would airflow back here be helpful?
Caps? (Apologies, new to some of the lingo).

Indeed quiet and cool isn't impossible, the budget is the enabler/disabler. What you desire is not impossible, but the the way you're going about it is just going to keep causing you grief sir.
I would like to do the impossible. :) (Cool + quiet + dual server CPU). How come HP managed to do it with my dual Xeon platinum 8180 workstation? Absolutely silent at idle, quiet under load...but loudish under crazy load.

For now I'm going to target the hotspots specifically as alex_stief mentioned earlier -- one thing at a time is a reasonable philosophy as long as I'm tinkering with fans. A 40mm for the one overheating RAM VRM, and an 80mm at an angle over the CPU VRM.

As for why one rig -- I want unified memory access for a number of jobs. With 2TB of RAM in there, it can hold large clustering jobs, in-RAM low-latency DB lookups, and more that do not work as well in a distributed system. Plus distributed systems take up more space, make more noise, etc.
 
  • Like
Reactions: Dreece

Dreece

int 21h
How come HP managed to do it with my dual Xeon platinum 8180 workstation? Absolutely silent at idle, quiet under load...but loudish under crazy load.
HPE are magicians, plus the masters of virtually every stage of the build from the motherboard through to bios right through to what materials they use for every inch of the box they put together. Off-the-shelf parts guys don't have those kind of magical powers, but we can achieve similar albeit with a lot of testing/trialling... keep us posted on your journey!!!