Seeking advice on a potential 3995WX "budget" build.

[ghxst]

What's WSL? Maybe it works when you limit it to use only one CPU?

How about support for ECC RAM? Maybe it's not too relevant for compiling stuff, but I'd always go with ECC rather than without. I guess Epyc CPUs need to support it well; on Threadrippers it may be merely an afterthought.

Windows Subsystem for Linux, it would be limited to one CPU from what I understand yeah. ECC would definitely be nice, I do run some high uptime things frequently.

Excuse me but who of those has better "single core" perf in passmark? I am not sure from the way you write.

The 3 at the end on the Epyc SKU number denotes the generation, this being Milan based on Zen3.

Your 3995WX is 3ed gen Ryzen which is Zen2 based and basically Epyc Rome on a different platform with a PCH.

5th Gen TR Pro would be generationally Milan.

Those things aside.
The Asrock Rack EpycD8 only supports Epyc 7001 and 7002 CPUs.
Not the 7003, which the 7713 and 7C13 both are.
For that you would need the Asrock Rack RomeD8 which funnily enough supports all 3 depending on the Bios.

Have you looked into what you are getting with Zen2 vs Zen3 based CPUs?

Have you considered that Epyc Servers usually lack the ability to sleep and suspend?

Or what about the fancy new features of Zen4 and Zen5?
Why not a 9th gen AM5 setup?

How much do you value single core performance?

The comparison I was making was a score of 2637 for the Epyc 7713 and 2598 for the 3995wx.

Thanks for the details, I understand it a bit better now.

I would go with a 9th gen AM5 setup but the PCIe lanes have me a bit concerned because I have a few optane drives, additionally the memory options are worse due to the shared lanes and limited ECC support, and networking wise I think there's only 1 motherboard that would give me a 10gb nic, otherwise I'd have to use a PCIe slot and well .. we come back to the first issue I mentioned.

Overall the performance of a 9950x or even a 7750x(3d) is great, just that the limits that come with it are concerning.

 

[6c352e2e-f287-445a-9cd3-d]

How much do you value single core performance?

Hm that's a very interesting question when it's for compiling code.

You could argue that it doesn't matter much because the number of cores makes up for single cores working slower. You can also argue that it's crucial because you don't want to wait for the result, and a bunch of faster cores will get you results in less time. But do you get as many cores with CPUs having faster cores?

You also need to consider the rest of the system. If the cores need to wait on storage or on remote machines running distcc, you may not get the results as fast as you imagine while the superfast cores have to idle.

You're making a good point with Epycs suffering from insomnia. That probably goes for most servers?

Is it possible to rent compile time from hosting providers? Perhaps they can rent out machines with 128 cores or so and you end up relatively cheap when you use them maybe twice a day for half an hour each?

 

[6c352e2e-f287-445a-9cd3-d]

Windows Subsystem for Linux, it would be limited to one CPU from what I understand yeah. ECC would definitely be nice, I do run some high uptime things frequently.

Just run Windows in a VM if you need it, and there's no restriction. Or get two r730s.

Or get even more r730s. If distcc works fine for what you're doing, you could scale up to 256 cores with 4 of them. That gets around the limitations of having everything in a single machine. It's sometimes better not to overwhelm a single machine with stuff and to use several instead.

 

[ghxst]

Is it possible to rent compile time from hosting providers? Perhaps they can rent out machines with 128 cores or so and you end up relatively cheap when you use them maybe twice a day for half an hour each?

I rented a box using a 9454P and one using a 7950x3d both on Hetzner, for the overall build performance especially for major versions of Chromium the 9454P performs a lot better, but when testing out small patches (which is most of my day to day work) I found the 7950x3d to have a lot better performance when it comes to linking speed.

That's why I am thinking a 9950x or 7950x3d might be fine for me, but again I'm concerned with the limited PCIe lanes, memory and motherboard choices, the options in that regard just seem way better on the threadripper or epyc platforms, though the epycs suffering from insomnia as you call it I hadn't considered before, I will look into how big of an issue that would be for me.

 

[ghxst]

Ok I'm thinking I might be able to compromise on PCIe lane requirements if I stick to only 1 Optane drive and settle for a single 5G nic, I would also have to drop the ECC memory and probably stick with 96GB of RAM if I would want to run at EXPO speeds.

Man ... If only AM5 had 8 more PCIe lanes or at least a better motherboard lineup this choice wouldn't be so difficult.

I'm tempted to just sit out another generation at this point but I also don't see it becoming a lot better, a sRT5 system would give me everything I want with a 7960x as CPU, it about matches the 3995wx multi thread performance from the benchmarks I saw but at a way higher single core perf, but it will be double the price of an AM5 system just for more PCIe lanes and registered ECC memory.

I guess I'll keep my eyes on any good deals for a while and look into distcc / icecc for the time being and wait a little longer to use my Optane drives, such a shame

 

[RageBone]

AM5 can work with Udimm ECC.
If you want gurantees, Epyc now is AM5 as well.

I feel you on the 8 extra lanes.

What AM5 board are you considering?
And what do you not like about it?
Whwt about the Asus Proart?

 

[ghxst]

AM5 can work with Udimm ECC.
If you want gurantees, Epyc now is AM5 as well.

I feel you on the 8 extra lanes.

What AM5 board are you considering?
And what do you not like about it?
Whwt about the Asus Proart?

Hmm I totally missed that the Proart has a 10g NIC, the bifurcation options also look pretty solid, it's a little bit on the expensive side but so are the server boards, if it can do x8/x8 between the top 2 lanes then I would be able to use a PCIe adapter for 2 Optane drives on the second slot and still have a slot left over on the chipset for peripherals (?) and 2 m.2 on the CPU, I will look into it! I guess the downside would be that if I go with UDIMMs for ECC then I'd kinda be forced to go with 64GB instead of 96GB if I want to populate only 2 slots, but that might be a worthwhile tradeoff.

 

[ghxst]

Am I missing something or are the DDR5 ECC UDIMM options way worse than the DDR5 ECC RDIMM options? For RDIMM I can get 6000MHz+ at as low as C32, but the UDIMM kits I see are all way 5600MHz max at super high CLs like CL46, are there some specific kits / brands I should look for?

 

[RolloZ170]

Am I missing something or are the DDR5 ECC UDIMM options way worse than the DDR5 ECC RDIMM options?

retail: Kingston
KSM48E40BS8KM-16HM
KSM48E40BS8KI-16HA
KSM52E42BS8KM-16HA
KSM56E46BS8KM-16HA
other rare are OEM

For RDIMM I can get 6000MHz+ at as low as C32

only with XMP enabled, if your mboard doesn't support XMP they run @4800 (except Gskill Zeta R5=jedec 5600)

 

[RolloZ170]

but the UDIMM kits I see are all way 5600MHz max at super high CLs like CL46, are there some specific kits / brands I should look for?

JEDEC std.voltage 1.1V (not overclocked )
with XMP,EXPO voltage 1.25V and higher...

 

[ghxst]

retail: Kingston
KSM48E40BS8KM-16HM
KSM48E40BS8KI-16HA
KSM52E42BS8KM-16HA
KSM56E46BS8KM-16HA
other rare are OEM

only with XMP enabled, if your mboard doesn't support XMP they run @4800 (except Gskill Zeta R5=jedec 5600)

Gotcha, I am looking for 2x32GB but will browse Kingston a bit further. I would be combining it with a 9950x on a ProArt X870E, I am not sure if it would run at XMP speeds if the kits aren't EXPO verified, do you have any experience with that?

 

[RolloZ170]

Gotcha, I am looking for 2x32GB but will browse Kingston a bit further. I would be combining it with a 9950x on a ProArt X870E, I am not sure if it would run at XMP speeds if the kits aren't EXPO verified, do you have any experience with that?

no but 9950x & ProArt X870E supports UDIMM only
i have the Kingston 6000 CL 32 you found, they are RDIMMs and need XMP/EXPO enabled for this, Intel 45/th gen / EPYC platform.

 

[ghxst]

no but 9950x & ProArt X870E supports UDIMM only
i have the Kingston 6000 CL 32 you found, they are RDIMMs and need XMP/EXPO enabled for this, Intel 45/th gen / EPYC platform.

Yeah I was wondering why there are no CL32 UDIMMs, the RDIMM options are much better, maybe I should go with threadripper after all :/

 

[RolloZ170]

Yeah I was wondering why there are no CL32 UDIMMs

doable in theory. but most DDR5 ECC UDIMM systems are server not WS/Gaming with RAM OC support.

 

[ghxst]

doable in theory. but most DDR5 ECC UDIMM systems are server not WS/Gaming with RAM OC support.

True, that's fair. I originally thought the same for ECC RDIMMs but I guess those are commonly used for high end workstations, I found a decent amount of workloads that scale well with low latency it's definitely not just gaming, but definitely not as high priority for normal server workloads I suppose.

Thanks for all the advice so far, I appreciate it!