[hami11]

Hey all,



I'm looking to get a desktop for CFD (with a little CAD and FEA analysis). Right now I'm thinking of getting an intel desktop but can't decide between 11th and 12th gen processors. From what I understand 12th gen is worth the upgrade if you use DDR5 memory, which is a little pricey and potentially not worth the upgrade. For my budget right now I'm looking at getting either the i7 11700k (ddr4) or i5 12500 (ddr5). The 11700k has 2 more cores than the 12500 but uses ddr4, and here is where things get confusing for me. I heard that ddr5 was supposed to substantially increase performance but looking at geekbench 5 benchmarks (benchmark is dependent on number of cores and memory bandwidth, similar to CFD benchmarks) between the 2 cpus it shows that the 11700k is slightly faster than the 12500. Is this because the memory bandwidth is not saturated by the 8 cores and so speed is only dependent on number of cores or is the geekbench 5 benchmark unrelated to cfd performance?

[hami11]

also, it looks like the i7 12700 would only be slightly faster than the 12400, as it only has 2 more performance cores, right?

[wkernkamp]

Originally Posted by hami11

Hey all,



I'm looking to get a desktop for CFD (with a little CAD and FEA analysis). Right now I'm thinking of getting an intel desktop but can't decide between 11th and 12th gen processors. ....I heard that ddr5 was supposed to substantially increase performance but looking at geekbench 5 benchmarks (benchmark is dependent on number of cores and memory bandwidth, similar to CFD benchmarks) between the 2 cpus it shows that the 11700k is slightly faster than the 12500. Is this because the memory bandwidth is not saturated by the 8 cores and so speed is only dependent on number of cores or is the geekbench 5 benchmark unrelated to cfd performance?

Geekbench is not a good benchmark for CFD. The Intel Core CPU's have just two memory channels. That will be the bottleneck. The CPU's are rated for DDR4-3200 or DDR5-4800. The DDR5 gives 50% more bandwidth.

[ErikAdr]

As wkernkamp says, go for DDR5 memory. I would choose a 13600 or a 13700, where the 'default' memory is DDR5-5600. It is very easy to overclock DDR5 memory if it supports XMP 3.0 (Intel). I think I would buy DDR5-6400, but many boards supports DDR5-7200 or higher. That include boards based on the cheaper chipset B760. Two DDR5-6400 matches the bandwidth of four DDR4-3200.

Newer Ryzen cpus using DDR5 could also be relevant. In that case, choose DDR5 Ram supporting AMD Expo. But I think Intel cpus can yield a higher memory bandwidth than AMD Ryzens, and that is what matters most in relation to CFD.


Correction: After reading your first post I realized your budget is very tight: Then, I would go for a 12500 (or 12400), a board with a B660 chipset (or B760) and DDR5-6000 supporting XMP 3.0.

[hami11]

So the ryzen 7700x with 5200-ddr5 should be faster than the 12600k with 4800-ddr5?

[ezy_nerdist]

I recommend you to keep 11700k.As it works perfectly.

[hami11]

What do you mean it works perfectly, please elaborate.

[flotus1]

My current understanding is that Zen4 Ryzen CPUs have the same old problem with fast memory: the interconnect between CCDs and IOD can't keep up. And the frequency of the infinity fabric can't be clocked high enough to make use of faster memory. From the tests I have seen, it appears the 7700X with its single CCD is particularly problematic.
DDR5-5200 is slow enough to hide this issue though.

[hami11]

Originally Posted by flotus1

My current understanding is that Zen4 Ryzen CPUs have the same old problem with fast memory: the interconnect between CCDs and IOD can't keep up. And the frequency of the infinity fabric can't be clocked high enough to make use of faster memory. From the tests I have seen, it appears the 7700X with its single CCD is particularly problematic.
DDR5-5200 is slow enough to hide this issue though.

So the 12600k should be faster than the 7700x? Also, what would be a rough estimate of the performance gain from 12th gen intel to 13th gen?

[flotus1]

Out of the box without tweaking anything, there is probably a small lead for the 7700x.
The I5-12600k has the advantage of being able to run higher memory frequency, and benefiting more from it.
So it depends on what kind of memory you want to use.
13th gen Intel is not really worth the price increase. You mostly get more E-cores for that money.

[Simbelmynë]

I have been absent from the hardware scene for quite some time. This comment was interesting though:

Originally Posted by flotus1

The I5-12600k has the advantage of being able to run higher memory frequency, and benefiting more from it.

Previous generations was quite the opposite, at least if we were comparing the gains below the 1:1 IF maximum. I have seen some reports of lower memory latency for the 7000 series compared to the 13000 series. The 13000 series seems able to push a bit more bandwidth though at the same memory settings. If Intel scales better with 6400+ MT/s memory then it is probably a better choice. All 7000X CPUs seems to have a bad case of voltage regulation and thus draw too much power. The plain 7000 CPUs that just released have much better performance/Watt ratio.

My bet is that the 7000 series X3D versions paired with tight-timing 6000-ish MT/s memory will be the best option for a general purpose desktop setup / cheap CFD workstation. Supposed launch in February.

[hami11]

Yeah, I won't be getting a desktop for a while so I will probably wait for the 7000 3d processors.

[hami11]

Originally Posted by flotus1

Out of the box without tweaking anything, there is probably a small lead for the 7700x.
The I5-12600k has the advantage of being able to run higher memory frequency, and benefiting more from it.
So it depends on what kind of memory you want to use.
13th gen Intel is not really worth the price increase. You mostly get more E-cores for that money.

So if I use ddr5 above 6000 MT/s the intel should outperform the amd chips? Also, it says on intel that the max supported ram speed for 12th gen is 4800mhz. Wouldn't that mean using ddr5-6000 vs 4800 would have no performance increase for alder lake chips?

[Simbelmynë]

Originally Posted by hami11

So if I use ddr5 above 6000 MT/s the intel should outperform the amd chips? Also, it says on intel that the max supported ram speed for 12th gen is 4800mhz. Wouldn't that mean using ddr5-6000 vs 4800 would have no performance increase for alder lake chips?

Desktop CPUs usually admit quite a large overclock on memory. Check the motherboard vendor qualified list of RAM to get an idea what you can expect to achieve just by activating the AMD/Intel RAM profile in the BIOS. It is not guaranteed, but quite likely that it will work 24/7.

This means you can easily ignore the DDR5 4800 rating of alder lake.

[ezy_nerdist]

Originally Posted by hami11

What do you mean it works perfectly, please elaborate.

Well I want to say if you are looking for a fast performance then 11700k works perfectly.

[juniorjune]

Originally Posted by hami11

Hey all,



I'm looking to get a desktop for CFD (with a little CAD and FEA analysis). Right now I'm thinking of getting an intel desktop but can't decide between 11th and 12th gen processors. From what I understand 12th gen is worth the upgrade if you use DDR5 memory, which is a little pricey and potentially not worth the upgrade. For my budget right now I'm looking at getting either the i7 11700k (ddr4) or i5 12500 (ddr5). The 11700k has 2 more cores than the 12500 but uses ddr4, and here is where things get confusing for me. I heard that ddr5 was supposed to substantially increase performance but looking at geekbench 5 benchmarks (benchmark is dependent on number of cores and memory bandwidth, similar to CFD benchmarks) between the 2 cpus it shows that the 11700k is slightly faster than the 12500. Is this because the memory bandwidth is not saturated by the 8 cores and so speed is only dependent on number of cores or is the geekbench 5 benchmark unrelated to cfd performance? mini militia download

Intel Core i7 processors tend to be faster and more powerful than Core i5 CPUs. The latest i7 chips offer up to 6 cores and 12 threads, making them better suited for advanced multitasking.
The Intel Core i5 is a general-purpose processor that delivers solid performance for gaming, web browsing, and basic work. The Intel Core i7 has more processing power and is better suited for high-performance gaming, content creation, multimedia editing, and professional applications.

i think you should choose the intel core i7 11700k because from my point of view it is better than i5 12500k so take care thanks...