Understanding how ASW and frame rates / performance relate with Quest Pro

[markturner1960]

I am currently running 90Hz and slider full right (No other settings in OTT, ODT or OXRPT while I troubleshoot) . In the instant action or training missions, I am getting pretty good performance but did notice one thing I wanted to ask about......I have the advanced overlay for the performance tools on ( nothing else) to get a feel for performance and notice that even though My CPU overhead is good (+60 to 70%) and GPU overhead OK (+20 to 30%) the frame rate is changing between 45 and lower values in various parts of the map. I would have thought that to step below the 45 mark, the overheads would need to be negative surely? Is that how it works? My understanding is this:

At current settings, ASW is on auto ( I think thats the default and have not changed anything in OTT etc) so if I see 45 FPS, then I can assume ASW is on. If I have good overheads for CPU & GPU, then it should not drop below 45 , correct? It should only drop down below if the overheads are being pushed into negative territory as resources get pushed by whatever demands the mission puts on the CPU & GPU . Is that correct? If so, I wondered why I was seeing FPS below 45 when I still had good overhead......?

When I dip below the 45 number, I start getting noticeable stutters and lack of smoothness......

[some1]

What do you mean by overhead, how do you measure that?

[markturner1960]

Hi, if you enable the overlay in OXRPT, you get the choice for FPS, advanced or developer which give basic FPS or more advanced information. If you use advanced, it give FPS and underneath, CPU & GPU headroom expressed in the format +20%. This is what I am referring to. 

I take this to mean that the higher the +percentage numbers are, the higher your frametimes and the better the system is working.....

But I have no idea how it works! 

Edited June 26, 2023 by markturner1960

[VitS]

Its 20-30% overhead for 45 fps, not 90 fps

[markturner1960]

Thank you - Yes, that is what I assumed. My query was why I was getting dips below the 45 FPS, without going into negative overhead? 

[Hippo]

On 6/26/2023 at 3:43 PM, markturner1960 said:

OXRPT

Apologies, but what is this?

[slughead]

6 hours ago, Hippo said:

Apologies, but what is this?

Sounds like he means the OpenXR Toolkit.

[slughead]

@markturner1960 have you set the target frame rate to 90? This is just under the setting for FPS/Developer/Advanced.

[Hippo]

2 hours ago, slughead said:

Sounds like he means the OpenXR Toolkit.

I assumed so but I don't see...

 

On 6/26/2023 at 3:43 PM, markturner1960 said:

CPU & GPU headroom expressed in the format +20%

when I run it, in the overlay I just see frame times (not percentages), and nothing about headroom?

Edited June 29, 2023 by Hippo

[nikoel]

5 hours ago, Hippo said:

I assumed so but I don't see...

 

when I run it, in the overlay I just see frame times (not percentages), and nothing about headroom?

 

See slughead's instructions above. They wont display unless you tell OpenXR Toolkit what FPS you're aiming for 

[Thinder]

On 6/26/2023 at 11:30 AM, markturner1960 said:

I am currently running 90Hz and slider full right (No other settings in OTT, ODT or OXRPT while I troubleshoot) . In the instant action or training missions, I am getting pretty good performance but did notice one thing I wanted to ask about......I have the advanced overlay for the performance tools on ( nothing else) to get a feel for performance and notice that even though My CPU overhead is good (+60 to 70%) and GPU overhead OK (+20 to 30%) the frame rate is changing between 45 and lower values in various parts of the map. I would have thought that to step below the 45 mark, the overheads would need to be negative surely? Is that how it works? My understanding is this:

At current settings, ASW is on auto ( I think thats the default and have not changed anything in OTT etc) so if I see 45 FPS, then I can assume ASW is on. If I have good overheads for CPU & GPU, then it should not drop below 45 , correct? It should only drop down below if the overheads are being pushed into negative territory as resources get pushed by whatever demands the mission puts on the CPU & GPU . Is that correct? If so, I wondered why I was seeing FPS below 45 when I still had good overhead......?

When I dip below the 45 number, I start getting noticeable stutters and lack of smoothness......

For a start, you're losing in performances with a RAM kit working out of your CPU Controller limits, it throttle down under load, tested back to back the difference with mine was <> 31% at 4K, you don't notice that when not under load.

With BDie. only the 8GB sticks posses 1 rank, your Controller is limited to 4 x 1 ranks, so the result is a loss of about 30%+ under load, meaning higher latency, lower bus bandwidth for both RAM and GPU.

No matter what you do as settings this bottleneck is there to stay until you limit the number of ranks and bring it back to a value your CPU Controller can manage.

The values you see and call overhead are the maximum your gear could reach in best conditions probably not what your CPU Controller delivers.

The Specs of your CPU are:

 

System Memory SpecificationUp to 3200MHz

AMD assume that you will not use a BDie kit and give the lowest frequency value, valid for example with a Cl16 kit

 

For 3600MHz, that's with a BDie Kit working at Cl14 4 X 1 rank maximum, I even wonder how you managed to have your BIOS taking the 3600MHz setting but it depends on Motherboard manufacturers, some will let you set it at 3600MHz with 8 ranks some won't, in any case the result will be the same, your settings will show the maxi, the Controller decide if yes or no it delivers and when it can.

 

The DDR4 Ryzen have the same controller in common, your 5900X works the same way than mine, the only difference is a higher clocking and no cache, but it is designed for lower latency like all recent DDR4 Ryzen, their controller limits ARE 3200MHz with "high street" RAM (non BDie/Cl14), 3600MHz with Cl14 kits, maximum of 4 ranks either 2 X 2 or 4 X 1.

 

The ultimate configuration for them is a 4 X 1 Cl14 kit providing your CPU with interleaving, meaning your Controller can manage data between all 4 sticks.

 

My opinion, I would swap this kit for a 32GB, you won't lose but gain in performances because for the same frequency, your kit will recycle data way faster than a 64GB kit can ever do, it's a case of more means less.

 

Then again, Lower FPS doesn't have to mean unplayable, it all depends on your frame time, so latency matters a lot and you don't get the best out of your combo with this RAM bounding, I run tests at high DCS settings, tree tops in the Caucasus map, the FPS doesn't look fabulous but I have no or very little flickering, it's smooth.

 

Low FPS can be normal under load, what is not is lower image quality, flickering, ghosting etc, VRAM and RAM plays a major role here, VRAM frequency helps with frame time, RAM helps your CPU to keep your channels open and your GPU to work under the best conditions possible.

 

Now I'm gone to the point where the limits are that of my headset, not my combo, ghosting and flickering showing in the Pico but not in the replays, so I'm not bothered with mid-40 FPS for as long as the game stays smooth and I still have some margin with VRAM frequency...

 

Edited June 30, 2023 by Thinder

[markturner1960]

Hi Thinder, interesting.....this is the memory in my system: https://www.scan.co.uk/products/64gb-2x32gb-corsair-ddr4-vengeance-rgb-pro-black-pc4-28800-3600-non-ecc-unbuffered-cas-18-22-22-42-1?_gl=1*hzcwvn*_ga*MTE5Nzg0ODMzOC4xNjg4MTA1MjMy*_ga_8GFH5M08Q5*MTY4ODEwNTIzMi4xLjEuMTY4ODEwNTMyMC4wLjAuMA..

Are you able to link what you recommend instead? And are you saying I cant get 64GB in that configuration? As I would prefer that...

Is this what you mean? https://www.ebuyer.com/1138634-corsair-vengeance-rgb-pro-64gb-ddr4-3200mhz-cl16-desktop-memory-black-cmw64gx4m4e3200c16?utm_term=&utm_campaign=PLAs||Components||Memory+-+PC||Med&utm_source=adwords&utm_medium=ppc&hsa_acc=4863007528&hsa_cam=9521594357&hsa_grp=100976037001&hsa_ad=421883255971&hsa_src=g&hsa_tgt=pla-1150328002936&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=EAIaIQobChMI-Jqwqavq_wIVh9LtCh1lcQiLEAQYAiABEgLHOPD_BwE

[markturner1960]

Or this, but huge price difference? https://www.conrad.com/p/gskill-trident-z-rgb-pc-ram-kit-ddr4-64-gb-4-x-16-gb-3200-mhz-288-pin-dimm-cl15-15-15-35-f4-3200c15q-64gtz-2383651?WT.srch=1&vat=true&utm_source=google&utm_medium=organic&utm_campaign=shopping&srsltid=ASuE1wQZ4pVY8F6_ZVYBJSxhActh9qlNhRknkWVig4FxGLAZyEOB228Tp-A

[Thinder]

17 minutes ago, markturner1960 said:

Hi Thinder, interesting.....this is the memory in my system: https://www.scan.co.uk/products/64gb-2x32gb-corsair-ddr4-vengeance-rgb-pro-black-pc4-28800-3600-non-ecc-unbuffered-cas-18-22-22-42-1?_gl=1*hzcwvn*_ga*MTE5Nzg0ODMzOC4xNjg4MTA1MjMy*_ga_8GFH5M08Q5*MTY4ODEwNTIzMi4xLjEuMTY4ODEwNTMyMC4wLjAuMA..

Are you able to link what you recommend instead? And are you saying I cant get 64GB in that configuration? As I would prefer that...

From what MSI are saying (and they don't talk about GSkill or Corsair but BDie kits), there are no 16GB sticks possessing 1 rank, I had one such a kit, G.SKILL TridentZ RGB Series 64GB (4 x 16GB) 288-Pin PC RAM DDR4 3600 (PC4 28800) Desktop Memory Model F4-3600C14Q-64GTZRA tested back to back with the one I have now, G.SKILL TridentZ RGB Series 32GB (4 x 8GB) 288-Pin PC RAM DDR4 3600 (PC4 28800) Desktop Memory Model F4-3600C14Q-32GTZRA it loses <> 31% at 4K 2 X MSAA in 3DMark Pro Firestrike.

With a Ryzen designed for low latency, especially the 5800X 3D with its cache, there is no advantage whatsoever in bounding a 64GB kit to those CPUs.

About the price, just to say "Do what I say not what I do"... The 3200MHz kit will OC to 3600MHz no problem, this will help cut cost, I tested all 3 kits, the 3200MHz was excellent but I elected not to O.C my RAM, it is just a matter of personal choice. G.SKILL TridentZ RGB Series 32GB (4 x 8GB) 288-Pin PC RAM DDR4 3200 (PC4 25600) Desktop Memory Model F4-3200C14Q-32GTZR

Edited June 30, 2023 by Thinder

[markturner1960]

OK, thanks.....can you clarify why you are using the 3600? To confirm, you recommend the last kit linked, which is a 3200? And that if I install that kit, I will see a large performance increase at load in VR? Apologies for teh simple questions, I am no expert in this stuff...Will it be straightforwards to swap it out? 

[some1]

On 6/26/2023 at 4:43 PM, markturner1960 said:

Hi, if you enable the overlay in OXRPT, you get the choice for FPS, advanced or developer which give basic FPS or more advanced information. If you use advanced, it give FPS and underneath, CPU & GPU headroom expressed in the format +20%. This is what I am referring to. 

As I understand it, this indicator is a simple calculation based on your current frametimes and target FPS that you have set in OpenXR toolkit, right below the Overlay option.

For me it works correctly when I have the target FPS set to 90 FPS. Then when the ASW kicks in it shows "GPU bound" in red, it doesn't show free overhead any more. But for CPU it shows  some weird things, like it only includes "app CPU" frametimes when calculating overhead, and not "rdr CPU" shown right below that. I checked a heavy mission that is more CPU than GPU bound, and the overhead % shown by OpenXR do not look correct there compared to frametimes below. I don't know why there are now two CPU counters, they are not described on OXR website (https://mbucchia.github.io/OpenXR-Toolkit/overlay.html)  @mbucchia would need to chime in and tell us how to interpret these numbers.

Enabling turbo mode can also make this numbers inaccurate I think, but I don't use that.

As for the RAM discussion, I wouldn't expect large gains in your situation, especially if you are more GPU than CPU bound.

 

[markturner1960]

ok, in my case, I am at 72 hz currently, so should set target to that, yes? ( I changed from 90hz....) 

[some1]

Yes, definitely. It only affects the counters, the FPS throttling setting is in a different place.

[Thinder]

1 hour ago, markturner1960 said:

OK, thanks.....can you clarify why you are using the 3600?

I did already: The 3200MHz can easily be O.Ced but my personal choice was not to O.C my RAM, the 3600MHz kit was available, I had the budget to change kit (again, 32GB 3200MHz, 64GB 3600MHz, 32GB 3600MHz all tested back to back).

I have to specify one thing, the loss one can experience with using the wrong combination of RAM with a Ryzen, is different between the X3D and non X3D CPUs, due to the way cache uses low latency that other "standard" Ryzen doesn't, it was explained clearly by AMD at the launch of the 5800X 3D, the goal of adding a cache was lower latency.

What it does, it shortens the time the CPU needs to access data, add to that the lower  latency provided by a Cl14 BDie kit and the difference is showing, so if you call the recovery of data loss a gain, the gain of using a Cl14 kit will be lower for a non X3D CPU although it is already important overall it translates differently.

From Crucial Cl16 to GSkill Cl14 3200MHz both 32GB. CPU is a 5600X

From 5600X to 5800X 3D.

As you can see for yourself, tests after tests have demonstrated gains but the most important step was achieved with the addition of the cache with the 5800X 3D, a gain of 18.91% in graphic score shows how the CPU keeping the GPU channel open helps with those scores. ALL at 4K 2 X MSAA.

In short, best bounding possible for this particular CPU affecting the GPU performances as well, in the case of simply going from a Cl16 to a Cl14 with a non 3D CPU gain is only 1.33% in Graphic Score but the CPU gains 6.04% (Physics Score).

 

  

1 hour ago, markturner1960 said:

OK, thanks.....can you clarify why you are using the 3600? To confirm, you recommend the last kit linked, which is a 3200? And that if I install that kit, I will see a large performance increase at load in VR? Apologies for teh simple questions, I am no expert in this stuff...Will it be straightforwards to swap it out? 

I recommend it in the frame of your remark on cost, if you have the budget and dont want to OC your 3200MHz, go for the 3600MHz kit, but be aware, 3600MHz is the limit of what a Ryzen will take.

For the gains see Slide 1 to which you can add the recovery of losses due to the number of ranks if you swap from a 64GB kit.

I deleted the last slide (third) which is irrelevant to the topic...

Quote

Will it be straightforwards to swap it out? 

Depending on your Motherboard BIOS, it can ID it and you won't have to even set the frequencies up or you will have to go to BIOS and set them manually, I had both cases since I changed Motherboard twice since the B450/5600X combo.

If you follow tutorials and user guide instructions it is pretty easy to do, those are standard RAM and timings, make sure your Motherboard and BIOS supports them.

Edited June 30, 2023 by Thinder