Question on CPU versus GPU bottleneck

[dburne]

Ok so if according to fpsVR my GPU runs around 20ms and my CPU around 11ms, which one is the bottleneck?

I am running an i9 9900k at 5.1 GHz all cores and RTX 3090 GPU. I was holding off getting a 4090 as I thought my CPU would hold me back? GPU is like at 98% utilized and CPU around 30% or so.

Edited December 17, 2022 by dburne

[Steel Jaw]

I am wondering the same thing for VR...my GPU runs at 100% load in VR the CPU around 45% andso Im guessing a CPU upgrade to a 1200 socket (from my current 1151) will have little to no effect on VR performance.  Too bad if so given the heavy discounts on the 1200 socket CPUs and MOBOs.  A GPU upgrade is way out of reach. 

[edmuss]

Your CPU won't currently be significantly bottlenecking your GPU as you're working the GPU so hard.  As the GPU frametimes come down towards you CPU frametimes then it will start to become a bottleneck.  Some missions will always cause slowdown due to the CPU but if you're generally holding 11ms (90fps) then you will probably be ok.

That said, the faster throughput of a newer CPU (intel 13th/ryzen 7xxx) will let a 4090 properly spread it's wings.

[Brainfreeze]

Uour GPU takes twice the time to render a frame than your CPU.  Getting the 4090 will lower your GPU frametime to around 11ms (my own experience) as well so will be a good match to your CPU.  

BTW I am using openxr rather then openvr so don't have the vrfps measure 

[edmuss]

17 minutes ago, Brainfreeze said:

Uour GPU takes twice the time to render a frame than your CPU.  Getting the 4090 will lower your GPU frametime to around 11ms (my own experience) as well so will be a good match to your CPU.  

BTW I am using openxr rather then openvr so don't have the vrfps measure 

Note that the CPU time shown by fpsvr/openxr is only the time taken for the CPU to render the frame before it's pushed to the GPU. Other things in the background will thrash the CPU to within an inch of it's life which will bottleneck the current setup.

I rather think that in the current climate, a 9th gen Intel is going to lacking soon when paired with a 4090. That said with the move to the new engine it will likely be a better match up

[dburne]

Well dang sounds like I may need to rethink my strategy on staying with 3090 this go around. Not doing a new build for about another year.

Thanks for the feedback gang.

Edited December 17, 2022 by dburne

[Slammin]

You want a 4090, even though I'd wager a 4090 will cause your CPU frametime to increase as well, at least with DCS.  Currently, it looks like your system has almost perfect balance.

[dburne]

Thanks gang, well I am taking kind of a lackadaisical approach to this thing. Not in any big rush so I just put myself in to be auto notified with the MSI US store when they get a 4090 Suprim in stock to sale. If one comes available and I can get it I will, if not I will just keep waiting.

I guess the main upside if I do the upgrade is at least I will still be able to get a half way decent price for my 3090.

[Dogmanbird]

The 4090 over the 3090 made a noticeable improvement for me, with all other hardware remaining the same. MSFS2020 also noticeably benefitted even though it reported I was CPU bound

I'm not sure it's worth going for a specific brand/model of card this generation as traditional under volting & clocking isn't making much of a gain if someones wanting to experiment with overclocking etc. It seems like focusing more on price, availability, warranty period and "will it fit into ones existing case" is the key this time around   One of the MSI models is the physically smallest version if I remember correctly

Edited December 18, 2022 by Dogmanbird

[Steel Jaw]

Why are GPUS still so overpriced?

[dburne]

4 minutes ago, Steel Jaw said:

Why are GPUS still so overpriced?

Demand I suppose. Scalpers. You can find them all day long over 2k for sale by scalpers. Scum of the earth.

Edited December 18, 2022 by dburne

[Dogmanbird]

there might be a more recent chart than this

[dburne]

At least in my case space is not an issue. I am though going to hold out for an MSI card. No real reason other than just because I think it is the one I want.  No big rush anyways, it is not like I am not enjoying DCS immensely every day.

[Dogmanbird]

fair enough

if anyone else is like me and tend to keep cards for a loooong time, the gigabyte Gaming and Aorus Master cards have 4 years of warranty after registering on their website

[SharpeXB]

2 hours ago, Steel Jaw said:

Why are GPUS still so overpriced?

Crypto mining 

[Dogmanbird]

On 12/19/2022 at 12:16 AM, Steel Jaw said:

Why are GPUS still so overpriced?

the last 1 to 2 years has revealed that people will still pay for the fastest cards regardless of the price (just like Australian cigarettes)

[Supmua]

Gigabyte rtx 4090 is still available on Bestbuy website, the FE was restocked briefly earlier today but all gone now.  Basically buy before the GPU tariffs hit next year (Q3 I think) if you can get it at MSRP, expect the price to go up even more afterward.

Edited December 20, 2022 by Supmua

[dburne]

This GPU situation is so ridiculous. Only ones that have them are scalpers and I would not buy anything from a scalper. They can burn all I care.

EVGA set aside GPU's with a que system for 30xx cards, shame they dropped GPU's now. Only company that tried to look out for us enthusiasts. In fact that is how I got my 3090 FTW3 Ultra when I did, through the que system. Worked great for me. I sure do miss them.

Edited December 20, 2022 by dburne

[Dogmanbird]

I wonder why we have so much 4090 stock in aus where other parts of the world don't?

[nikoel]

1 hour ago, Dogmanbird said:

I wonder why we have so much 4090 stock in aus where other parts of the world don't?

Because in 'Straya the cheapest are thirty two hundred kangaroos mate. The mid to upper end will go as far as 3.6K+. Consumers have been shafted over the last couple of years; were looking for a reprieve, but Jensen's Johnson had other plans

Which makes people fall into two categories broadly

1st - Wallet can't stretch that far

2nd - Wallet can. But butthole and/or dignity can not

Mining is no longer very profitable, as Eth has completed it's transition to proof of stake and the pyramid scheme has imploded for the time being

P.S. Checked US market and they can be had on Newegg and Microcenter right now. Same in HongKong and Taiwan. The supply is rather good

Edited December 21, 2022 by nikoel

[Dogmanbird]

2.85 kangaroos for the poverty models at the moment (if one catches the 15% 24hr ebay specials)

[nikoel]

1 hour ago, Dogmanbird said:

2.85 kangaroos for the poverty models at the moment (if one catches the 15% 24hr ebay specials)

Whaaa.. how does that work?

After Ebay and PayPal fees the seller would be only getting ~2.4K

Edited December 21, 2022 by nikoel

[Dogmanbird]

they are from our local shops who also sell on ebay, such as Umart, Scoptec and Computer Alliance, then minus the ebay discount. I got mine from Umart minus 20% about 5 weeks back. I've only seen 10 - 15% lately though

[Steel Jaw]

So, would it be worthwhile for me to upgrade my CPU from my current I5/8600K  socket 1151 to a i5-11600K socket 1200, if my current CPU is only running at 60% load with DCSW in VR?

Edited December 22, 2022 by Steel Jaw

[edmuss]

Percentage CPU load is an incorrect metric to use because it's over the total number of cores, you have 6 cores, DCS uses approximately 2.5 of them and then there's additional overheads like windows that makes up your 60%.  You will find that DCS will be loading 1 core up to 100% pretty much constantly and the others will be just working away.  The more cores you have, the more the CPU utilisation goes down with the current engine, when the new engine is launched and more threading is enabled then CPU usage will rise.

What is important for DCS is single core performance, compare the 8600k to 11600k and make a judgement.  Generally higher clock speeds are better but the 5800x3D has proved that it's not the only metric that matters, at 4.45Ghz it's as fast as the 12900k at 5+Ghz.  Additionally newer CPU architecture has higher throughput so my old 4.7Ghz i5 2500k would be much slower than my 4.45Ghz x3D.