What’s the best way to use an i9?

[Neil Gardner]

I’ve e got a new system. The specs are

Asus PRIME X299-A Motherboard
NVIDIA GeForce GTX 1080 Ti 11GB Graphics Card
SKU NVIDIAGTX1080TI11GB
32GB DDR4 2400MHz Memory (2 x 16GB Sticks)
SKU 32DDR42400MHZ2X16
Seagate 3TB BarraCuda 7200RPM Hard Disk
Intel Core i9-7900X CPU, 10 Cores, 3.3 - 4.3GHz
Corsair Hydro H100x CPU Cooler
Windows 10 Home 64-bit
Corsair RM850x 80 PLUS Gold 850W PSU
1TB Samsung 960 EVO M.2 PCIe Solid State Drive

It’s my retirement present to myself and in principle it should blow P3Dv4 out of the water. But, as usual (many years of upgrades to hardware and yet finding that FSX onwards barely improves in performance), there would seem to be only a marginal increase in performance. Does anyone know how to get more bangs for your buck?

Thanks
Neil

[Neil Gardner]

Sorry, I’ve put this on the wrong forum.

[downscc]

I'm curious as to how you define performance. For many, and this is a misconception, their primary metric is frame rate.

We have similar systems except I've got a 6 core CPU with a slightly newer chipset (z370 vx z299), and this was an upgrade from a 4 core CPU running about the same mid-4GHz range. The change in performance after my upgrade was marginal, there was one but it wasn't something I could quantify. It just seemed to have more fluid animation. I finally saw some improvement in rendering difficult scenery (complex aircraft, complex overcast clouds, complex scenery with dynamic lighting) when I added a 1080Ti to create a SLI configuration.

Don't expect anything available at a reasonable price to "blow P3D out of the water." We got used to software being the limit to our simulation world until P3Dv4 went to 64b and now we need to get used to the way things have always been (except for the past 6-8 yrs) that our hardware struggles to keep up with software. Improvements are going to be incremental. I suspect even if the rumored 8087K were available today it wouldn't blow P3D out of the water, but I'd still probably start planning my next build.

[Neil Gardner]

Fluidity, fluidity, fluidity every time. I don’t care about FPS.but it is the lack of fluidity at the mo that is my chief disappointment. I have notched up the sliders one place or so, and now have pretty much t(e same FPS, but even the F22 at Egan fluctuates FPS, to give noticeable fast-slow sensation. I have Digital Combat sim as well and those models fly so smoothly that my ambition is to have P3D v4 do the same whilst still being able to enjoy decent graphics. I think one weak point for me is the monitor, which was good for my previous set up-it is a max res 1920*1080 - but I think I may now have allot of power backing up against the monitor which maybe better off as a 4K. Maybe, I don’t really know. But other than that I understood that Rob Ainscough experienced a considerable improvement in performance with his i9.

[downscc]

Agree, fluidity and that is more about experiencing fewer long frames and stutters than achieving high frame rates. I'm not sure if Rob has done anything different with the i9 than I have with my six core i7-8700K. First, forget most tweaks including an affinity mask... I don't use one. The only tweak I use is because I have more than 8GB VRAM I use the texture size =10 setting but that acts to increase significantly the workload on the system, but my 1080Ti SLI (I think Rob has this too) handles the workload no problem.

There are still occasional long frames but that is not due to any performance bottleneck, I believe it to be a residual software limitation not yet resolved by LM. Other than these scenery object loading induced long frames, your animation should be very fluid. The 4K display really makes a difference but not sure it improves fluidity other than requiring less aggressive AA, and maybe that is something to evaluate.

[Neil Gardner]

Dan,
Thanks for the reply. Things are settling down a bit but I’m still feeling a little ‘short changed’ in the sense that I can’t go much higher with settings and get smooth graphics and I’m wondering if I might be missing something. I agree about the tweaks. I’ve been messing with FS since 2002 and tried every ‘snake oil’ solution there is is. The only thing that’s ever seemed to help in the past is affinity mask, but you don’t think this would help? I wouldn’t know what to set it for, for an i9 anyway.

[AnkH]

The problem is, sorry to say, that your 10 cores are basically not helping you at all in Prepar3d. Although multicore support is much better than back in the FSX days and v4.x also makes more use of a potent graphics card, you still need as much single-core performance as possible. And this is the Problem here: your 1000$ i9 has a base core frequency of "only" 3.3GHz, at least it has a all-core turbo of 4.0GHz. Means: while your i9 runs with 4.0GHz max if more than two cores are used, most i7 (8700K) run with 5.0GHz. This is a difference of 25% which can not easily be compensated by the higher cache of your i9 or by the additional cores (basically it can not be compensated at all...).

Verdict: you either try to get higher clockspeeds on all cores (4.7-5.0GHz, might not be possible with this cooling solution or your chip...), or you arrange yourself with the fact that the i9 was not the ideal Investment for P3D...

EDIT: ah, and then I see you use 2x16GB. Why not 4x8GB? The X299 Chipset and it's CPUs support quad channel. Also there you loose some of your potential. Honestly, who configured you such a rig for P3D? Might have been worth getting some Feedback BEFORE buying it...

[Sam Iam]

Howdy,

I'm new to the scene but not new to FS (since 1996) and an 18 year I.T. professional. I'm curious why we don't look at where the bottleneck truly is in flight simulation.

I'd like to suggest that there is/was a huge latency due to OOM and now 64-bit has addressed this. Then, memory can't hold everything needed to run such a complex simulator so disk speed MUST be considered here. Nominally, I SATA 3 legacy (7200 RPM - 10K RPM) hard drive can do reads of approximately 250 Mb/sec. The average SSD reads at approx. 480-560 Mb/sec. That's 2x the speed of what Neil has. Now, there are the M.2 / PCIe NVMe drives (aka Samsung 960 EVO). This is what I've just installed in my new rig I finished yesterday. Read speeds are an astounding 3 Gb/sec; a 600% increase in speed over a typical SSD.

I've been out of flight sim for a few years now and just getting ready to install P3D for the first time over FSX boxed. I also have the i9 but the 7980XE. No, I don't think I'll gain that much but, I do a lot of video rendering as well which is the reason for this CPU. I believe that the NVMe drives will make a huge difference with fluidity TBH. Just my opinion and time will tell.

Sam

[Airwolf]

I too brought this point in avsim about the use of ssd

[dsymanow]

Neil -

I have almost identically the same system, and I'm really happy with the performance.These are the tweaks that made the biggest difference.

Turn off hyperthreading in the BIOS. I don't know why, but with hyperthreading enabled I get stutters, and without it things are smooth.

In P3D config I set TEXTURE_BANDWIDTH_MULT=66. This eliminated most texture load delays. I believe this makes better use of the PCIe SSD (I use three, one for the OS, one for P3D, and one for scenery).

I also use FIBER_FRAME_TIME_FRACTION=0.5 in P3D cfg.

My CPU is over-clocked to 4.5 GHz. I use a Corsair water cooler. For me, the difference in OC between 4.0 and 4.5 GHz is not big.

I'm using a 55" HDTV. I have VSYNC turned on in P3D and in the nVidia control panel. I set it to 30 Hz and unlimited frame rates. If I turn VSYNC off I get stuttering even though the frame rates are high, because they are variable, and your eyes see the difference as a stutter.

Hopes this helps.