X299 or TR4 processor selection
 

Hi all! :)


I'd like to ask for your help to decide the best option for my needs to update my desktop computer to do use it mainly with Star CCM+. I feel the need to update it because it's painfully slow to do a DES simulation with my current configuration.

Currently I have the following build in terms of microprocessor, motherboard and RAM memory:

• i7-6700K (4 cores, dual-channel memory).
• Asus Z170 gaming-pro motherboard
• (16x4)GB CORSAIR VENGEANCE LPX DRAM DDR4 2400 MHz

A part from CFD, I would like to use it for gaming purposes, that's why I'm not considering any Intel Xeon option.


So, I would like to know from you if the previous generation of Ryzen Threadripper 2920X or 2950X (other options with more cores and the newest generation are too expensive for me) would fit for both uses, or whether if I need to stick with intel and go for the newest generation of Core i9-10900X, Core i9-10920X or Core i9-10940X. Similarly, the
Core i9-10980XE it's the most expensive option and I'm not sure if it's worth it.


It makes any real difference to have for example 10 cores instead of 18 or 32 cores?


Additionally, would I need to update my RAM memory with better clock speeds?


Thanks in advance to all of you and I hope that you can help me to take a good decision based on my needs!

I have a few random thoughts about this, but even I struggle to make a clear recommendation these days. So here goes my stream of consciousness:

Let's start with the obvious:
How many cores can you use with the license you have?
And how much money do you want to spend approximately?

About your non-CFD requirements: If modern Xeons are too slow for the type of games you play, then so are first- and second-gen Threadripper CPUs. There, that was easy to rule out :D

So what's left is Intels HEDT lineup. In general, more than 3 cores per memory channel yield very little benefit in CCM+. Which CPU is best suited for you, will depend on your budget and license.

Getting faster memory would be a good idea to go along with it. E.g. 4x16GB DDR4-3600 currently go for less than 300€.

Thank you very much for your answer flotus1!

Initially I used to have a serial session + the power tokens to cover up to 6 cores. But recently we were upgraded to a power session license to be a more cost-efficient option when it comes to a workstation with more cores.

I have a rough idea of a top budget of 1K-1.2K€ including microprocessor and motherboard. RAM upgrade would be in a separate budget.

@flotus1 additionally from my previous answer, I would like to ask you your suggestions or recommendations about any potential candidate for the given budget that I have for any Xeon microprocessor.


I think that I have to rule out the latest Ryzen Threadripper 3rd gen because it's just nonsense for my needs a 24-core or 36-core processor, and I'm not quite sure about the latest gen of intel i9-109XX processors because they're still based on the "old" 14nm technology and it seems from what I read on the internet that Intel is currently a step behind from AMD.



As I said before, any suggestions would be very much welcome!


Thanks!:)

Intels HEDT lineup has definitely fallen behind AMD in every possible way. Core for core and clock for clock, Zen2 beats every current Intel microarchitecture. The only thing Intel has is a lower entry bar and generally lower prices.

Reverse-engineering the question from your budget: You will need about 200-300$ for a decent X299 motherboard. This leaves you with 2 options: 14 cores or 12 cores. Both are valid choices, I would probably go with the 12-core SKU. The additional cores won't help much, and you can spend the saved money on a 280mm closed loop water cooler.
I don't see a good reason to go with a Xeon CPU instead. You can't use higher memory speeds, the CPU clock is locked, and you spend more money on the CPU.

Thanks for your answer @flotus

So I think that I'll go for a 14-core option because I already have a good cooler which is the Corsair H115i and it already gives me good results and it is compatible with the Intel 2066 socket and buying an additional adaptor, it also works with the TR4 socket.


So my final choices in order of preference are:

1. If AMD releases new processors with less cores for the 3rd gen of Threadripper, then it will be the best candidate to go for it.

2. If I find somewhere to buy it in Spain, I'd go for the 2nd gen 2950x.

3. Currently, the 2920X is available for 417€ which is also good option to consider which suits what you said of a 12-core SKU.

4. And the final option would be to go for the Core i9-10940X

So once again, many thanks for you help @flotus1

If AMD would release an entry-level Threadripper 3000 CPU with 16 cores, it would be the better option compared to the top end of X299. Depending on the price of course. But I would not count on that, Ryzen seems to cover this niche for most users.

About a year ago I was where you are, wanted to run Star with a little gaming, and I went with the 1950x. I've been very happy with it, runs airfoils and Assassins Creed Odyssey on high/ultra settings (granted I have a gtx 2070) really well.
I have been told the Corsair new water coolers (like the 115i) technically fit over the TR4 socket but not very well (the Threadripper chip is huge) so you may want to look into that if you go with a Threadripper. I use the Noctua 14S and have never had a thermal problem.

Thanks for your answer @Chris2337!

I'm just waiting until someday AMD and Intel start to sell the Threadripper 3960X or the i9-10940X. These two are my final options to go for.


But I have a final question that any of you may be able to put some light into it: which platform could have more lifespan, the old intel LGA 2066 or the newest AMD sTRX4?


To tell you the truth, I don't know what to buy because finally money wouldn't represent a problem, so it's no longer a restriction for me.

Wait, what? With money not being a relevant factor, buy TR 3000.
Might have been a relevant piece of information to start with.

Socket 2066 is definitely on it's last leg, there won't be any upgrade path. Nobody knows what AMD is planning with their TRX4 socket, and if they made any claim about supporting it for x amount of generations, don't believe them.

Ditto what flotus1 said, with the TRX4 socket just being unveiled it'll be around for a couple years, although AMD has stuck to the AM4 socket for the regular Ryzen line like they said they would so I would give them credit for that. They're no Intel (yet).
I haven't seen any benchmarks for CFD on the 3960x yet, but considering the base clock and new architecture it is probably head and shoulders above the last generation. Anyway, itll be awesome compared to your i7-6700K.
Make sure you get a decent power supply, like 1200 watts.

Wattage on the label does not equal quality for power supplies. What you should be looking for is working protection mechanisms, stability and quality of the output voltage, and efficiency if you are into that.
Unless the intention is to set world records with LN2 overclocking, A decent power supply in the 600W range (costing 100-120€) will be enough for a "standard" build with a 24 or 32 core TR3000. Maybe 700W when paired with a highend GPU.

Thanks for your answer! In my earlier posts, I was talking about a top budget, but after looking at the selling prices and that I could have the chance to pay it in instalments, these are the reasons from this week that has made change the scenario.

So in my case I think that it wouldn't represent an issue because I currently have the Corsair HX850i.

I have a new question related with RAM memory. The new Threadripper socket supports up to 256GB of RAM, is there any point to go up to this value or it would be more than enough if I go for 128GB of RAM?

As I told you in my initial post, what I currently have is (16x4)GB CORSAIR VENGEANCE LPX DRAM DDR4 2400 MHz. I plan to keep these RAM sticks that I have although they're not the best in terms of frequency, but it would represent any problem if I buy (16x4)GB CORSAIR VENGEANCE LPX DRAM DDR4 3200 MHz to get up to 128GB of RAM?

Finally, I will buy the following:

• AMD Ryzen Threadripper 3960X
• ROG Strix TRX40-E Gaming
• RAM memory according to your suggestions

Thanks!

Hey, sorry I forgot to reply. For the power stuff 1200W is probably excessive, but for my build I originally had a 700W supply and my computer would randomly turn off. I installed a 850W supply and haven't had an issue since. I do also have to power a RTX 2070 GPU, but from looking around my symptoms were common with being under powered. I also know somebody that built with a 2970x and they went with a 1000W to be safe. Obviously my first PSU could have been faulty but my notion is if you're going to spend $2500 on a computer then spend the extra $50-$100 to make sure what powers it is quality and a little more than you could ever need.

With the RAM I think it largely depends on what you plan on doing with the computer. I'm an aerospace engineer in graduate school so I use my PC to run airfoils and post-process airplanes. I could run the airfoils with 16GB of RAM no problem. The airplane files can be up to 225,000,000 cells which uses all of my 64GB of RAM to evaluate field values like vorticity, or fails trying. Again I have a 1950x, but I think 128GB would work well (with 3200MHz) and 256GB is probably more than you would need.
I would imagine that board has 8 RAM slots so you could buy 64GB and then another 64GB if/when you need it.

Just some thoughts from my build, flotus1 might have some inputs.

Yeah, might have been a slight overreaction on my part. But the general gist of it in my opinion is: these problems with PSUs are very often caused by cheap PSUs with high wattage on the label, but less oomph on the inside. We are on the same page, skimping out on a PSU, especially in an expensive workstation, is the wrong way to save money. I would just feel more comfortable spending 120€ on a 700W PSU, instead of a 1200W PSU.

@topic
You are the only one who knows how much RAM you need. Commercial CFD solvers need in the order of 1-4GB per million cells while solving. Depending on single- or double precision, and the solver type used. Adding more physics like chemical reactions can push this number even higher.
Just for gaming, there is no benefit from more than 32GB.

Mixing different types of memory usually works, as long as you stay within the official specs. Which should be DDR4-2666 for TR3000 with 8 dual-rank DIMMs.
Buying the same name from the same brand is still no guarantee for trouble-free operation. The actual ICs can still vary.
If you ever want to run the CPU near its optimum DDR4-3600 speed, you will probably need one memory type only.

My recommendation would be selling your old memory, and buying new. RAM is cheap these days, starting at 4€/GB for DDR4-3600. Who knows how long prices will stay down. And IMO it would be a bit sad to bottleneck this 1400$ CPU with slow memory.

Thanks to Chris and flotus1 for your answers!

For your info, what I mostly do with Star CCM+ (double precision) is external aero + cooling of road cars and race cars.
For steady state simulations, I use the coupled solver, k-omega SST turbulence model, trimmed mesh.
For transient simulations, I try to experiment with both the segregated and the coupled solver, and the K-Omega SST DES turbulence model.
When possible for case simplication, I go with half car simulations, but I usually go for full car simulations, with moving ground, MRF for wheels...

@topic
Flotus1, I have and additional question from your last reply. I've searched in the AMD website for the figures and it says that the "System Memory Specification" is 3200MHz. So, correct me if I'm wrong, but if I'm not mistaken this is the frequency that I should buy instead of the DDR4-3600MHz that you say?

DDR4-3200 is the official spec for one 16GB DIMM per channel or less. So far, so good.
But just like Ryzen 3000, TR can benefit from using faster memory, especially in CFD. See e.g. here how much performance can be gained on this Architecture by optimizing memory timings and frequency: https://www.cfd-online.com/Forums/ha...y-timings.html
If we are being pedantic, this is overclocking. But the risk of damaging anything is virtually zero, and as long as you check for the stability of your overclock at the beginning, it will not affect stability of the system later.