• Guest, The rules for the P & N subforum have been updated to prohibit "ad hominem" or personal attacks against other posters. See the full details in the post "Politics and News Rules & Guidelines."

3900x vs 7820X

Stealtharsenal

Junior Member
Sep 3, 2012
20
2
71
Good Evening everyone.

I am wondering if anyone knew or possibly did some benchmarking of the i7 7820X versus the 3900x. Currently I have a 7820x on an Aorus Ultra Gaming x299 board with 32gb of Corsair 3000 mhz ram. I have the CPU clocked at 4ghz. With that said, I do have a 3900x sitting here, but I do not have a board in yet for it. I am beginning to wonder realistically if one has a significant advantage over the other. I do a mixture of usage with my machine. It is a gaming machine and a work machine (when I work from home). I also game on 3440x1440 primarily (I do have a 4K display as well). From a work perspective, I am utilizing AutoCAD 2019 Civil 3D, Revit 2019 and ARCGIS as my primary programs. There are a couple of other work programs but I don't use them nearly as much.

Any potential insight would be helpful.

Thanks
 

tamz_msc

Platinum Member
Jan 5, 2017
2,344
2,046
106
Are your work programs capable of utilizing multiple cores really well? If not then I would not bother with the 3900X.

You also have your 7820X clocked quite low. It can easily do 4.5GHz with good cooling. If you're feeling that performance is not adequate, then you should try upping the clocks and see how it goes. Also Skylake-X benefits from overclocking the mesh, so I'd try that as well.
 

Thunder 57

Golden Member
Aug 19, 2007
1,051
706
136
I think the 3900X makes more sense. It's a newer platform and has more of a future to it. It has an extra four cores. I'm not sure about AutoCAD but I think the others would favor the 3900X. Gaming is probably a wash, or maybe better on the 3900X. I say this because Skylake-X is not the gaming chip that mainstream Intel is. Not to mention you are running higher resolutions. Skylake-X certainly isn't bad at gaming, though.

If you do overclock it more, it would be more of a fair fight. But stock vs stock, I'd say the 3900X any day.
 

ehume

Golden Member
Nov 6, 2009
1,464
62
91
. . . You also have your 7820X clocked quite low. It can easily do 4.5GHz with good cooling. If you're feeling that performance is not adequate, then you should try upping the clocks and see how it goes. Also Skylake-X benefits from overclocking the mesh, so I'd try that as well.
I thought it was because I do not know OP's chip, but I agree. Further, increasing the clocks on your CPU involves no monetary outlay. You can save your money for the next iterations from Intel and AMD.
 

Arkaign

Lifer
Oct 27, 2006
19,909
418
126
3900x is better. Heavily overclocked 7820 will close most of the gap and even lead in some situations.

100 times out of 100 the choice between 3900x and 7820 today would be 3900. However, I also think the value in changing platform right now is basically zero unless you feel like reinstalling everything and can get a premium for your used parts (you might! Those mobos are $$$).

But personally, as it seems you like premium products, I'd wait for Zen2 Threadripper, or at least the 3950x, where you'd see a genuine leap from even an OC 7820. As is it would be a lot like going 8700k to 3600x. A big ehhhh for a lot of effort.
 
  • Like
Reactions: OTG and lightmanek

misuspita

Member
Jul 15, 2006
101
58
101
, I'd wait for Zen2 Threadripper, or at least the 3950x
That's what i would do. If you go from 7820 to 3900x will be a performance uplift, but not that great to really feel it. 3950x or TR when it appears might be another story.
 

TheGiant

Senior member
Jun 12, 2017
618
237
86
Good Evening everyone.

I am wondering if anyone knew or possibly did some benchmarking of the i7 7820X versus the 3900x. Currently I have a 7820x on an Aorus Ultra Gaming x299 board with 32gb of Corsair 3000 mhz ram. I have the CPU clocked at 4ghz. With that said, I do have a 3900x sitting here, but I do not have a board in yet for it. I am beginning to wonder realistically if one has a significant advantage over the other. I do a mixture of usage with my machine. It is a gaming machine and a work machine (when I work from home). I also game on 3440x1440 primarily (I do have a 4K display as well). From a work perspective, I am utilizing AutoCAD 2019 Civil 3D, Revit 2019 and ARCGIS as my primary programs. There are a couple of other work programs but I don't use them nearly as much.

Any potential insight would be helpful.

Thanks
most CAD program benefit from single thread performance
skylake x is not bad, but its 2 years old so its aging
if you can get your chip running at 4,4GHz+, forget about 3900X, it is not an upgrade, just a sidegrade for this workload
for that gaming, try to increase the mesh speed to 3GHz or so, gaming will benefit from it

current ryzen 3 line bioses needs to be tuned for problemless experience
 

Atari2600

Senior member
Nov 22, 2016
950
977
106
Contrary to popular belief, CAD programs are not highly scaleable with cores.

It is CAE programs that really see the benefits of SMP.


Assuming because it is a work machine that you are not too eager to put massive overclocks on it [I'm same boat - having the thing running stable is more important than a few hundred MHz], so its stock vs. stock (or near enough).


Below link compares 7820X to 3900X:
https://www.anandtech.com/bench/product/2519?vs=2257

My conclusion would be - unless you are generating renders and fly-thrus on the machine based on your DMUs, then your probably better served just sticking with the 7820 and keeping the money in your wallet - or putting it toward monitors[1] or a space pilot[2].

[1]if you aren't running at least 40" 4k, get one, it'll make a bigger difference to your workflow than any incremental CPU change.
[2]never had cause to use one (don't use CATIA enough to justify) but been told they are the dogs balls.
 
  • Like
Reactions: OTG

Gikaseixas

Platinum Member
Jul 1, 2004
2,827
195
106
The 3900X is a solid upgrade for multithreaded apps, and a wash for gaming, but... perhaps the 3950X will give you what you seek, so wait a bit more

Edit - Consider Cascade Lake-X or Threadripper 3 later in the year also
 
Last edited:

VirtualLarry

Lifer
Aug 25, 2001
45,740
4,131
126
I don't know that I would overclock a "work" CAD PC. If a 3900X would deliver gains, over a stock 7820X, then yes, I would consider switching. AMD's "stock overclocking", aka "Boost", is pretty good, and you keep warranty, and is not really considered "overclocking", in terms of potentially losing stability.
 

TheGiant

Senior member
Jun 12, 2017
618
237
86
I don't know that I would overclock a "work" CAD PC. If a 3900X would deliver gains, over a stock 7820X, then yes, I would consider switching. AMD's "stock overclocking", aka "Boost", is pretty good, and you keep warranty, and is not really considered "overclocking", in terms of potentially losing stability.
well skl-x hit 4,4-4,5 without voltage rising and since 2C turbo is already 4,3GHz its not much of an overclock
The 3900X is a solid upgrade for multithreaded apps, and a wash for gaming, but... perhaps the 3950X will give you what you seek, so wait a bit more

Edit - Consider Cascade Lake-X or Threadripper 3 later in the year also
IMO cascade lake X is useless unless you need that mem bandwitch or avx512
with ryzen 3 previous so called HEDT is obsolete, not that I like that message from AMD that their 2950X is useless while 3900X exists, same like Intel with the skylake x refresh up to 10C lineup where 9900K is simply beating or equal
 

Atari2600

Senior member
Nov 22, 2016
950
977
106
The 3900X is a solid upgrade for multithreaded apps, and a wash for gaming, but... perhaps the 3950X will give you what you seek, so wait a bit more

Edit - Consider Cascade Lake-X or Threadripper 3 later in the year also
He/She will see far more return from investment in interface equipment than marginal* CPU upgrades.

*marginal as per improvement in this use case.
 

Stealtharsenal

Junior Member
Sep 3, 2012
20
2
71
Thanks everyone for responding. This is interesting for sure. I can see where the 3900X would be better, but at the sametime, I can see how the two are sort of on an even playing field in other regards to other benchmarks.

My 7820X is set at base clock of 4ghz and is boosting to 4.4. Seems to hold its boost fairly decently underwater. I don't recall the voltage it is running at, but I do seem to recall it being higher than I would like it to be to achieve this. It wasn't like my old 5820K that ran at 1.27v and hit 4.6 stable.

So what I was looking to achieve was a bit of an increase in both single core and multithreaded performance. I realize the commentary on core count and CAD, but I can say this. I do have a work laptop. I started with a Xeon 1505V3 quad in a laptop work machine last year and it just chugged with Civil 3D. I loaded all my files to my 7820X machine and everything flew and was smooth while utilizing most core (I think this is a functional distinction). I then had my employer upgrade my laptop to an i9 8950HK six core and that was way better than the quad in my previous laptop. I guess what I am saying here, core count and frequency do seem to affect CAD and Revit even though they don't "benefit from additional cores."

From a graphics standpoint so we are all on the same page, I just dropped a 2080TI into the system.

I can try bringing the clocks up more on the 7820X, but as a few mentioned above, I want to keep this thing stable. I rather not deal with continuous crashing or anything like that. Maybe I am better off looking for a used 7900-7940X and dropping it in. Maybe a board with a better power delivery would help.

As I mentioned, I have a 3900X sitting at home and a Crosshair Hero coming tomorrow I think. I could do some testing and see. I have to reformat my machine anyway, so the hassle isn't a hassle. I have a few new NVME drives to install.

Thanks
 

Atari2600

Senior member
Nov 22, 2016
950
977
106
I realize the commentary on core count and CAD, but I can say this. I do have a work laptop. I started with a Xeon 1505V3 quad in a laptop work machine last year and it just chugged with Civil 3D. I loaded all my files to my 7820X machine and everything flew and was smooth while utilizing most core (I think this is a functional distinction). I then had my employer upgrade my laptop to an i9 8950HK six core and that was way better than the quad in my previous laptop. I guess what I am saying here, core count and frequency do seem to affect CAD and Revit even though they don't "benefit from additional cores."
Somewhat surprising to me that it does see substantial benefit from going from 4 to 6 cores - although I am always reluctant to use laptops as a basis for comparison as so much throttling can occur.

You didn't make any memory changes at the same time?

If you've seen benefit, then so be it - I suppose keeping an eye on task manager will tell you if you are using 100% of your current 7840X's core/thread capacity.
 

TheGiant

Senior member
Jun 12, 2017
618
237
86
Somewhat surprising to me that it does see substantial benefit from going from 4 to 6 cores - although I am always reluctant to use laptops as a basis for comparison as so much throttling can occur.

You didn't make any memory changes at the same time?

If you've seen benefit, then so be it - I suppose keeping an eye on task manager will tell you if you are using 100% of your current 7840X's core/thread capacity.
I think OP made his mind before posting, 3900X is the choice
@Stealtharsenal

can you post your OEE with 7820X and 3900X, would be nice to see what and upgaded machine can do
 

Stealtharsenal

Junior Member
Sep 3, 2012
20
2
71
Normally, I wouldn't make a laptop comparison, but I am using a 17" laptop right now which is pretty hefty and doesn't got hot at all under load. Surprisingly, it cools very well. I am thinking its because the entire perimeter is a vent due to the P5000 in it. In any event, the comparison I was making is that core count from 4 to 6 to 8 made a huge improvement in workload. Now it is also kind of important to make mention that AutoCAD as Civil 3D is a resource monster in comparison to regular AutoCAD which I think a P4 could probably run just fine.

I left memory alone in the OC. As I mentioned, I was looking to remain relatively stable. Setting the multiplier at 4.0 for all cores was extremely stable. I know originally when I went to 4.1, it liked to crash quite often. I could certainly give it another whirl. If I can make do with my 7820X, I can look for a higher end X299 chip or just wait a bit longer and return the AMD stuff to microcenter.
 

Stealtharsenal

Junior Member
Sep 3, 2012
20
2
71
@TheGiant

Haha, I buy things and test, don't get me wrong. I have not decided one way or another if I am keeping the 3900X yet. I was looking for some commentary and obviously other benchmarks to get an idea. I am still going to pit the two against one another for my own benefit, but I wanted to see if I was in the same neighborhood. I mean I might do an about face and buy a an XE model and drop it into my x299 board. I am a wild card when it comes to computer hardware. I switch so often.
 

TheGiant

Senior member
Jun 12, 2017
618
237
86
@TheGiant

Haha, I buy things and test, don't get me wrong. I have not decided one way or another if I am keeping the 3900X yet. I was looking for some commentary and obviously other benchmarks to get an idea. I am still going to pit the two against one another for my own benefit, but I wanted to see if I was in the same neighborhood. I mean I might do an about face and buy a an XE model and drop it into my x299 board. I am a wild card when it comes to computer hardware. I switch so often.
sure

that doesnt change the quesion- what is your OEE with 7820X and 3900X? or what is the decision argument ?
 

B-Riz

Golden Member
Feb 15, 2011
1,226
293
136

Atari2600

Senior member
Nov 22, 2016
950
977
106
Now it is also kind of important to make mention that AutoCAD as Civil 3D is a resource monster in comparison to regular AutoCAD which I think a P4 could probably run just fine.
I had envisaged it would be similar to CATIA, which does not scale very well with threads.


edit: Just to clarify something I might be missing - are you running analysis jobs using any built in stress/vibration analysis sub-programs? Is that where you are finding it chugging? [does it even have any of these kinda things built in]
 

misuspita

Member
Jul 15, 2006
101
58
101
It might take a while to update their benchmarks, but they released Photoshop bench 2 days ago. Their conclusion:

Testing 22 different CPUs makes a bit of an overwhelming chart, but there are a few very clear conclusions we can pull from the results:
  1. AMD Threadripper CPUs are not good for Photoshop.
  2. Intel X-series CPUs are OK for Photoshop, but not an ideal choice for heavy Photoshop workflows since you can get more performance for less money with other CPU options.
  3. Intel 9th Gen CPUs are great for Photoshop.
  4. The new Ryzen 3rd generation CPUs are terrific for Photoshop.
https://www.pugetsystems.com/labs/articles/Photoshop-CPU-Roundup-AMD-Ryzen-3-AMD-Threadripper-2-Intel-9th-Gen-Intel-X-series-1529/
 

Stealtharsenal

Junior Member
Sep 3, 2012
20
2
71
So I am definitely getting some very interesting results. It's like a catch 22 right now. If I look at raw synthetics, cinebench r15 and r20 are quite a bit faster multicore and a bit faster single core. With R20, we are looking at 7105 multi and 503 single on 3900x vs. 4219 multi and 435 single on 7820x. R15 on the other hand saw 3077 cpu and 198 single on 3900x while the 7820x was 1774 cpu and 190 single.

Looking at time spy extreme, looking at a CPU score of 4495 on the 7820x clocked at 4.4 on all cores. I did not overclocked mesh, or run any ram faster than 3000mhz. With the 3900x, cpu pulled 6596 with 3200mhz ram. I should note that is out of the box settings. HWmonitor consistently had the 3900x between 4.3 and 4.4 on all cores. They all maxed at 4.4 to 4.6.

Fire strike ultra had the 3900x physics at 27932 with combined of 6936 while 7820x physics was 21145 with combined of 7071.

I'll update further in a bit with just a couple games. Too many to test do something like metro and tomb raider. I will also have a 2080ti tomorrow.
 
  • Like
Reactions: lightmanek

Stealtharsenal

Junior Member
Sep 3, 2012
20
2
71
So for some clarity here are the testing rigs:

- 7820x vs. 3900X

- Aorus X299 Ultra Gaming vs. Crosshar VIII X570 Hero

- 32 gb - 3000 Mhz ram (Vengenance) vs. 32gb - 3200 Mhz Ram (Vengenance)

- 1080TI FTW 3 vs. 1080TI FTW 3

- Clean install Win 10 Pro vs. Clean install Win 10 Pro

Fire strike ultra had the 3900x physics at 27932 with combined of 6936 while 7820x physics was 21145 with combined of 7071. I also ran Fire strike extreme and the 3900x was at 28015 physics and 6928 combined. The 7820x on the other hand was at 19174 physics and 5191 combined.

I tested just two games because I honestly wasn't expecting too much of a difference.

Tomb Raider (7820X) - Min FPS = 110, Max FPS = 120, Avg FPS = 119.1
Tomb Raider (3900X) - Min FPS = 106, Max FPS = 120, Avg FPS = 118

Metro Last Light (7820x) - Avg FPS = 97, Max = 175.65, Min FPS = 23.49
Metro Last Light (3900X) - Avg FPS = 100, Max = 185, Min FPS = 28.43

There is still room I suspect to overclock the 7820X more. I could mess with the mesh overclocking and bring the multiplier on the cores up more. I am on water, so I have a bit more headroom from a thermal perspective to work with. I also had the 7820X at 1.25V at the 4.4. Flipping to the 3900X for a moment, as I mentioned it was clocking up on boost to 4.3-4.4 but was doing so at 1.475V. I suspect I can maybe overclock a bit on the 3900X, but it would appear the 7820X might clock further. I clocked it on the fly without a crash so I think we can go further here.

I don't know, I could make the argument to keep the 7820X and return the 3900x or keep it. I could also see about faster ram in the X299 system and hang onto it until the 3950X or find say a 9900X and drop into my X299 board.

At this point, I would say it probably is an expensive platform swap for not too much difference. I would probably be better with a 9900K. I do have a 2080TI coming tomorrow, so either system will do fine with it. Not sure, maybe I am looking at this all wrong.
 
  • Like
Reactions: richierich1212

Zucker2k

Senior member
Feb 15, 2006
937
375
136
The 7820x is a capable overclocker. It'll do 4.8GHz easy 24/7. You have adequate cooling for it, too.
 

ASK THE COMMUNITY