Bernard Ducret

7700K, 8700K, 7740X?!... That is the question.

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I have read a number of threads here on AVSIM regarding the best CPU to run P3D v4 and remain perplex as to which CPU I should acquire for my next PC (exclusively for P3D) to be ordered shortly. Hence my list of CPU above in the title.

The latest Intel CPU i7 8700K would seem to be the logical choice, but some recent performance comparisons with the 7700K were less than convincing, I read also that the i7 7740X would comfortably top it in single core performance of - 485 vs 535 in the benchmark test of Guru 3d - which P3D (if I understood correctly the various informed comments) would capitalise on. Is this a correct assumption or did I misunderstand this debate since the multicore performance test was 3702 vs 2725, that is the opposite result...?

Lastly in terms of OC, it would appear that 5.0GHz is about the maximum one can expect regardless of the CPU, is that a fair assessment?

I would really appreciate any precise input from the knowledgeable few, which I - unfortunately - am not part of.

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Good questions.  Has anyone on these forums actually reported their results with the Coffee Lake 8700K or is this all speculation?

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There are already some terrific discussions on these processors here in the forums.  I'd check them out as there is some very important information - including some heat issues with one of those processors.

Best wishes.

 

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1 hour ago, DaveCT2003 said:

There are already some terrific discussions on these processors here in the forums.  I'd check them out as there is some very important information - including some heat issues with one of those processors.

Best wishes.

 

Believe me Dave, I did, but after reading pages and pages of conflicting opinions, I have yet to be in a position to make an informed decision, be it only because of what is still unclear to me between the "one core" or the "multi-core" performances as per my question above, until I understand what P3D actually requires, with FSX we knew what was necessary, now that I am jumping to P3D v4, I am in uncharted waters so I need first to understand (from the various comments, it is far to be clear even to specialists) and then decide on my own what is best...  

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After having read a lot in forums I finally decided for an 8700. Seems best compromise regarding price, single core speed and amount of cores. So just waiting for that to arrive next week...

Prozessor: Intel Core i7-8700K (6 x 3.70 GHz / 4.70 GHz)

RAM: 32 GB (2 x 16 GB) DDR4 SDRAM 2400 MHz

HD : 500 GB SSD WD Blue / 2 TB HDD WD Blue

Grafik: NVIDIA GeForce GTX 1080 Ti 11 GB GDDR5X ASUS ROG STRIX OC-Edition

Mainboard: ASUS ROG Strix Z370-F Gaming

 

Mike

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Running a 7740x comfortably here @ 5.0Ghz. To be honest I think you'll find maybe a frame or two of difference between these chips in V4. Hardly worth losing sleep over. For me the choice was one of being able to replace it and go to a higher end processor later. I don't think you could go wrong any way you go. 

For the minimal price diff I'd go with an 8700k if your going with a mainstream board... 

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Ah, understand!

You're right, at the moment there is some discontinuity with reports in our community.

Still, upgrading to more cores seems a logical next step (I'll be doing it next year) and one can always use Affinity Mask or Process Laso to keep the sim at 4 or 6 cores IF the sim hasn't efficently made use of the extra cores.  I'm confident it will eventually.

Why am I waiting?  Both the 7700K and 8700K have serious heat issues even when running at stock speeds, and Intel's response to irate customers was "don't overclock, don't change voltages, and don't delid these processors (pretty much standard warrant stuff) even though one of the main selling point of these processors was the ability to overclock.

I'm waiting for the dust to settle on all of this, and I'm also waiting to see how the solderless processor thing works out for Intel.  Additionally, I find my self a little curious about AMD processors after many years of shunning them. I'm not sold by any means, nor am I brave or rich enough to buy one to find out if it plays well with FSX/P3D.  I have contacted AMD though, and maybe they will send me a unit to test (I'm a former hardware computer engineer, so MAYBE they'll consider that and give me a system to test).

Best wishes!

 

 

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39 minutes ago, mikealpha said:

After having read a lot in forums I finally decided for an 8700. Seems best compromise regarding price, single core speed and amount of cores. So just waiting for that to arrive next week...

Prozessor: Intel Core i7-8700K (6 x 3.70 GHz / 4.70 GHz)

RAM: 32 GB (2 x 16 GB) DDR4 SDRAM 2400 MHz

HD : 500 GB SSD WD Blue / 2 TB HDD WD Blue

Grafik: NVIDIA GeForce GTX 1080 Ti 11 GB GDDR5X ASUS ROG STRIX OC-Edition

Mainboard: ASUS ROG Strix Z370-F Gaming

 

Mike

Mike,

I'm in the same boat as you as far as upgrading goes. I'm coming from a 2700k though. I don't know what your upgrading from.

I see thst you chose 32 8gb of ram. I have been mulling over whether or not to go with 16gb or 32gb of ram. Do you honestly foresee p3d v4 needing thst amount of ram? Or is it more just the fact that you can afford it? I can save over 150 bucks using 16gb of ram but I really want to make sure thst It's enough because I won't be building amother pc for a minimum of 6 years.

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Thanks to all who took the time to answer my query. I now understand that there is not a vast difference performance wise between all three CPU. I come from FSX run on a 3770K, so I decided to move on to P3D v4 since at long last we have a stable 64bits platform with most my add-ons from FSX that can be upgraded even at a marginal cost, except PMDG...

The other main components I am selecting are RAM: 32GB G.Skills Ripjaws V DDR4 3200MHz, MB: MSI Z370 Gaming Pro Carbon, HD: Samsung SSD 960 Evo M2 1 TB, Noctua NH-D15, GPU: I already have a Nvidia EVGA 1070 (to be upgraded next year with the new Volta).

Does anyone have comments on those elements, for RAM I gave precedence to lower frequency vs faster timing, for HD I opted for the M2 version giving at least 4 times better performance both in writing and reading. 

 

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1 hour ago, mikealpha said:

After having read a lot in forums I finally decided for an 8700. Seems best compromise regarding price, single core speed and amount of cores. So just waiting for that to arrive next week...

Prozessor: Intel Core i7-8700K (6 x 3.70 GHz / 4.70 GHz)

RAM: 32 GB (2 x 16 GB) DDR4 SDRAM 2400 MHz

HD : 500 GB SSD WD Blue / 2 TB HDD WD Blue

Grafik: NVIDIA GeForce GTX 1080 Ti 11 GB GDDR5X ASUS ROG STRIX OC-Edition

Mainboard: ASUS ROG Strix Z370-F Gaming

 

Mike

Mike,

Any reason you have elected to go with 2400 MHz RAM vs. 3200 ?  Maybe it makes no difference for P3D, I don't know.

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1 hour ago, DaveCT2003 said:

Ah, understand!

You're right, at the moment there is some discontinuity with reports in our community.

Still, upgrading to more cores seems a logical next step (I'll be doing it next year) and one can always use Affinity Mask or Process Laso to keep the sim at 4 or 6 cores IF the sim hasn't efficently made use of the extra cores.  I'm confident it will eventually.

Why am I waiting?  Both the 7700K and 8700K have serious heat issues even when running at stock speeds, and Intel's response to irate customers was "don't overclock, don't change voltages, and don't delid these processors (pretty much standard warrant stuff) even though one of the main selling point of these processors was the ability to overclock.

I'm waiting for the dust to settle on all of this, and I'm also waiting to see how the solderless processor thing works out for Intel.  Additionally, I find my self a little curious about AMD processors after many years of shunning them. I'm not sold by any means, nor am I brave or rich enough to buy one to find out if it plays well with FSX/P3D.  I have contacted AMD though, and maybe they will send me a unit to test (I'm a former hardware computer engineer, so MAYBE they'll consider that and give me a system to test).

Best wishes!

 

 

I like your thinking and style Dave, as I am waiting for the dust (and/or smoke) to settle too.

If for some reason Intel/AMD does not pick you as a tester with your qualifications, I will humbly submit my name as I don't have any whatsoever. :cool:

Kind regards,

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20 minutes ago, SpiritFlyer said:

If for some reason Intel/AMD does not pick you as a tester with your qualifications, I will humbly submit my name as I don't have any whatsoever.

You probably have a better chance than I do!  :)

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2 hours ago, DaveCT2003 said:

Ah, understand!

You're right, at the moment there is some discontinuity with reports in our community.

....

I'm waiting for the dust to settle on all of this, and I'm also waiting to see how the solderless processor thing works out for Intel.  Additionally, I find my self a little curious about AMD processors after many years of shunning them. I'm not sold by any means, nor am I brave or rich enough to buy one to find out if it plays well with FSX/P3D.  I have contacted AMD though, and maybe they will send me a unit to test (I'm a former hardware computer engineer, so MAYBE they'll consider that and give me a system to test).

Best wishes!

 

 

I too, am interested in the AMD Threadripper as an option to the Intel products. I did build a couple of AMD based computers some years ago for FSX. I found them to work well with FSX. I have priced components through Newegg. Reuising my box and PSU it will be $2300-$2500 for either a 8700 or AMD 1900X. What you might save on the CPU you will lose on the MOB. However, the extra cores in the AMD might lead to a better life, provided PD3 get better and better at multicore usage.

I do not pan on doing anything until after the new year. Maybe, by them we will have a better idea on the best direction to take.

 

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2 hours ago, ahsmatt7 said:

Mike,

I'm in the same boat as you as far as upgrading goes. I'm coming from a 2700k though. I don't know what your upgrading from.

I see thst you chose 32 8gb of ram. I have been mulling over whether or not to go with 16gb or 32gb of ram. Do you honestly foresee p3d v4 needing thst amount of ram? Or is it more just the fact that you can afford it? I can save over 150 bucks using 16gb of ram but I really want to make sure thst It's enough because I won't be building amother pc for a minimum of 6 years.

You can buy 16Gb in 8Gb sticks and then add two more later, if needed.

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27 minutes ago, jmig said:

I do not plan on doing anything until after the new year. Maybe, by them we will have a better idea on the best direction to take.

 

I agree. I can not afford to make the wrong choices in the fog of uncertainty and without clear direction forward.

There is no compelling reason for me to jump just because I have that particular itch.

Smarter for me to just scratch it :blush: and wait to see what comes next! :cool:

Kind regards,

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I am planning a new build to run P3D4 and possibly X-Plane 11.

Regarding CPUs I am confused about 'cores' and their importance in P3D4. 

I am also confused about 'delidding' as applied especially to Coffee Lake CPUs.

Could someone enlighten me please, as non-technical as possible. :happy:

John

 

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On 10/26/2017 at 4:30 AM, betelgeuse said:

I am planning a new build to run P3D4 and possibly X-Plane 11.

Regarding CPUs I am confused about 'cores' and their importance in P3D4. 

I am also confused about 'delidding' as applied especially to Coffee Lake CPUs.

Could someone enlighten me please, as non-technical as possible. :happy:

John

Sure, I'll try ;o)

Both P3DV and XP can use more cores than the typical 4-core CPU found in common gaming rigs of the recent past.   They don't use each core the same way:   most of the processing work needed to make the sim run, sometimes called 'the main thread' is done on only one of a multi-core CPU.  This means that what is referred to as 'single-core performance' of a given CPU arguably has the biggest impact on what role any CPU can play in either flight sim..   A CPUs single-core performance is generally based on two things: it's 'IPC', or Instructions Per Cycle as a part of it's logic architecture, and it's 'clock speed', expressed in Gigahertz.   Over the past 6 years or so IPC has improved substantially, and clock speed relatively slightly by comparison.  To put it where the goats can get it, my Sandy Bridge E processor, now over 5y/o, runs with all of its 6 cores at 4.42hz on relative low extra voltage, and the latest processors from Intel can run up near or above 5.0Ghz, w/ better IPC.  How big of an impact can we get comparing old SB-E CPU and today's top end processors?  I'm guessing around a 25-35% improvement if the top end processor runs at typical overclocked speeds possible today.  That is significant, while hardly overwhelmingly so.

Beyond the main thread done on one core, other cores are used by both P3D primarily for loading terrain textures.   I think this is true to XP 11 as well, and I think I read that other aircraft traffic in XP is handled in other available cores as well.

If I were shopping now for a CPU I wouldn't buy one with less than 6 cores which is what my SB-E has.   I've seen all 6 of my cores being utilized in P3D and since increases in single-core performance improvements are relatively meager one hopes at some point flight sim software develops to use those extra cores even more than currently is the case.  So while a 4-core CPU may get you slightly more single-core performance since it doesn't have be able to manage the heat demands of larger multi-core processors, the difference between the best 4 core and the best 6+ core CPU in terms of single-core performance isn't that large.  Therefore, I lean towards at least 6 cores, maybe 8 cores, for either flight simulator going forward.

Intel CPUs since Ivy Bridge 4-cores have been manufactured w/o soldering the Integrated Heat Spreader (IHS), otherwise known as it's 'lid', to the CPU's heat producing 'die' where all of the work is done.  They use a Thermal Interface Material (TIM) between die and IHS instead of solder and it is considerably less efficient in transferring heat to the IHS compared to solder.   My SB-E chip is soldered, and runs in the 50-57C temp range w/ all 6 cores running at 4.42Ghz on a Noctua air cooler.  It has become common to see temps in the 70-80+ with processors like the 8700K and that is with water or good air cooling.   By 'de-lidding', removing the IHS and reattaching with a more heat-conductive TIM, not solder, one can get temps lowered by 10-20C.  In general, with overclocking, the higher the clockspeed, the higher the voltage required, and the higher the temperature goes, so de-lidding can help the overclock go as high as it can.   When a CPU gets too hot it is automatically 'throttled back', i.e., it's clockspeed is reduced to help it stay w/in it temperature limits, and no one wants that to happen while flying ;o)

As a side point it's always a good idea if you can afford it to build with the best GPU you can afford along w/ the best CPU.   You've heard by now 'P3D/FSX is 'CPU-limited', meaning as you are flying thru complex scenery the demands of the sim's main thread exceeds what your CPU can do despite its overclocked state.   As well, the same can happen to your GPU since some of the sliders in the sim affect mostly the GPU, whereas others mostly the CPU.   

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This is just what I was hoping for, Noel. Thanks for taking time to explain these mysteries so clearly.  For the first time I understand why a Kaby Lake i7 at 3.8 GHz  runs faster than an Ivybridge i7 at 3.8 GHz.

The same goes for de-lidding. Just why a manufacturer would create a CPU capable of being overclocked without the necessary built-in heat protection disturbs me. In effect, Intel charges extra for a CPU that can be overclocked, but avoids warranty claims because of the need to de-lid it. A variant of Catch-22. Nice one, Intel!  

In the event, I bought a 8700K-based system with a 8GB GTX 1070 Ti, 16GB DDR5 etc. I usually build PCs myself but this time I'm buying a custom system from Scan PC (UK). This will be for P3D4 and possibly X-P11. I guess I will notice a difference from the Ivybridge set up I've been running for the past 6 or 7 years! 

Thanks again,

John

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On ‎27‎/‎10‎/‎2017 at 5:25 PM, Noel said:

Sure, I'll try ;o)

Both P3DV and XP can use more cores than the typical 4-core CPU found in common gaming rigs of the recent past.   They don't use each core the same way:   most of the processing work needed to make the sim run, sometimes called 'the main thread' is done on only one of a multi-core CPU.  This means that what is referred to as 'single-core performance' of a given CPU arguably has the biggest impact on what role any CPU can play in either flight sim..   A CPUs single-core performance is generally based on two things: it's 'IPC', or Instructions Per Cycle as a part of it's logic architecture, and it's 'clock speed', expressed in Gigahertz.   Over the past 6 years or so IPC has improved substantially, and clock speed relatively slightly by comparison.  To put it where the goats can get it, my Sandy Bridge E processor, now over 5y/o, runs with all of its 6 cores at 4.42hz on relative low extra voltage, and the latest processors from Intel can run up near or above 5.0Ghz, w/ better IPC.  How big of an impact can we get comparing old SB-E CPU and today's top end processors?  I'm guessing around a 25-35% improvement if the top end processor runs at typical overclocked speeds possible today.  That is significant, while hardly overwhelmingly so.

Beyond the main thread done on one core, other cores are used by both P3D primarily for loading terrain textures.   I think this is true to XP 11 as well, and I think I read that other aircraft traffic in XP is handled in other available cores as well.

If I were shopping now for a CPU I wouldn't buy one with less than 6 cores which is what my SB-E has.   I've seen all 6 of my cores being utilized in P3D and since increases in single-core performance improvements are relatively meager one hopes at some point flight sim software develops to use those extra cores even more than currently is the case.  So while a 4-core CPU may get you slightly more single-core performance since it doesn't have be able to manage the heat demands of larger multi-core processors, the difference between the best 4 core and the best 6+ core CPU in terms of single-core performance isn't that large.  Therefore, I lean towards at least 6 cores, maybe 8 cores, for either flight simulator going forward.

Intel CPUs since Ivy Bridge 4-cores have been manufactured w/o soldering the Integrated Heat Spreader (IHS), otherwise known as it's 'lid', to the CPU's heat producing 'die' where all of the work is done.  They use a Thermal Interface Material (TIM) between die and IHS instead of solder and it is considerably less efficient in transferring heat to the IHS compared to solder.   My SB-E chip is soldered, and runs in the 50-57C temp range w/ all 6 cores running at 4.42Ghz on a Noctua air cooler.  It has become common to see temps in the 70-80+ with processors like the 8700K and that is with water or good air cooling.   By 'de-lidding', removing the IHS and reattaching with a more heat-conductive TIM, not solder, one can get temps lowered by 10-20C.  In general, with overclocking, the higher the clockspeed, the higher the voltage required, and the higher the temperature goes, so de-lidding can help the overclock go as high as it can.   When a CPU gets too hot it is automatically 'throttled back', i.e., it's clockspeed is reduced to help it stay w/in it temperature limits, and no one wants that to happen while flying ;o)

As a side point it's always a good idea if you can afford it to build with the best GPU you can afford along w/ the best CPU.   You've heard by now 'P3D/FSX is 'CPU-limited', meaning as you are flying thru complex scenery the demands of the sim's main thread exceeds what your CPU can do despite its overclocked state.   As well, the same can happen to your GPU since some of the sliders in the sim affect mostly the GPU, whereas others mostly the CPU.   

THANK YOU!!

 

At last someone says it as it is.

The industry ( and the world in many regards ) has gone backwards and processors should be now in the 8 GHz mark, wether you agree or not with multicore perf.

 

 

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14 minutes ago, warning23 said:

The industry ( and the world in many regards ) has gone backwards and processors should be now in the 8 GHz mark, whether you agree or not with multicore perf.

And planes should be flying at Mach 8, except that they don't and for good reason. There's also a reason why clock speeds aren't much above 4Ghz - it's called the laws of physics. The heat and current leakage as you get above a certain speed gets prohibitive.

AMD and Intel are giving the market what the market wants - the market wants lower power and more cores. Most software has adapted. It says more about us that the simulators have not.

Cheers!

 

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On 10/28/2017 at 1:55 AM, betelgeuse said:

I guess I will notice a difference from the Ivybridge set up I've been running for the past 6 or 7 years! 

Looking forward to hearing a report on the performance increase as I am still on an Ivy Bridge myself.

Ted

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9 hours ago, Ted Striker said:

Looking forward to hearing a report on the performance increase as I am still on an Ivy Bridge myself.

Ted

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17 hours ago, Ted Striker said:

Looking forward to hearing a report on the performance increase as I am still on an Ivy Bridge myself.

Ted

I will post again in a new thread. The machine will arrive this week I hope, but it will take me a couple of weeks to get things installed assuming there are no major hitches.

It cannot be a direct comparison as I won't be comparing like with like. My FSX Ivybridge rig has to cope with a vast number of addons and non FS programs which will not be installed on the new machine.

The new PC will have P3D4 and X-P 11 only.

John

 

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On 10/21/2017 at 1:21 PM, jmig said:

You can buy 16Gb in 8Gb sticks and then add two more later, if needed.

The issue is those are a mismatched set and my not run at the rated speed together stabily.

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Quote

And planes should be flying at Mach 8, except that they don't and for good reason. There's also a reason why clock speeds aren't much above 4Ghz - it's called the laws of physics. The heat and current leakage as you get above a certain speed gets prohibitive.

It doesnt if you increase the size, and your comparison with a plane is ludicruous, ( and also wrong since there are planes reaching almost Mach 7 ) because you cant make a plane with engines that use more power due to size, you can though make a pc fast enough with the appropiate size and electric consumption. ( that is of course if you really want to , which is not the case with INTEL )

Quote

AMD and Intel are giving the market what the market wants - the market wants lower power and more cores. Most software has adapted. It says more about us that the simulators have not.

 

AAaaaaah, so now its not the laws of physics but the market. That is actually more correct on your part.

Nevertheless that is not what the market wants. That is what Intel wants because they dont want to spend the money in investigation and better fabrication.

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