Ram frequency affects rift tracking.

UnFknBLievable

i have a high end system running perfectly fine, stable and fast (i7 6700k @ 4.6ghz, gskill 3000mhz ddr4, GTX1080, win 10 and Asus z170-AR motherboard.

only adjusting the memory frequency between default factory speed (3000mhz) and underclocking it down to 2144mhz, why does the tracking system of the rift go from being unstable and often unplayable to flawless?

oculus can you look into this please? 

flexy123

Is your system in general stable? I mean tested with OCCT, Prime, memtest etc.?

danknugz

i actually have 3000mhz ram but the bios defaults it to 2100 unless i modify a special profile and use it (asus refers to this as "xmp") , never bothered to change it and in general never had any major issues

dougchism

Depending on the motherboard,  some have USB issues with XMP and overclocking. My guess is if your USB ports are being handled by the CPU or chipset, they probably are going to get timing issues with XMP and overclocking. If you are using ports attached to a 3rd party controller, or an add-on card my guess is they wont. 

I am building my new system right now ( specs below ) and will test it out with/without XMP and report back. 

kojack

I've heard other people a while ago (maybe on reddit?) say that turning the xmp profile on/off affected tracking, but it made no difference to me.

UnFknBLievable

Yes, my system is 100% stable at default memory speed (3000mhz). This is a direct relationship between all the rift problems I've had and Ram frequency on a Z170 motherboard. Last night I under clocked my Ram again for an Assetto Corsa Race and everything was flawless again. I tested this and can 100% confirm that my RAM frequency is affecting my Rift tracking.

Other USB devices such as my G25 racing wheel and my Saitek X52 Pro joystick are 100% stable at default (3000mhz) Ram frequency.

Danknugz - If you know how, I suggest trying to use your rift with your XMP profile or better yet, leave it disabled, set all RAM options to "Auto" and only change your frequency to it's factory speed and test your Rift. I would love to know your results. What is your motherboard?

Dougchism - I am considering changing my motherboard if this is a common problem with Z170 motherboards. I will have to test with XMP enabled with a slower RAM frequency, if my BIOS allows it.

PseudoSoul

Default RAM is 2133 on that chipset. The RAM manufacturer may rate it a 3000, but the MoBo will ultimately decide. I would go back to 2133, and OC everything else. If your VR is running well at that point, leave it alone.
The Rift can not be compared to other USB devices. It is a picky SOB.

UnFknBLievable

Directly off the Asus website.

4 x DIMM, Max. 64GB, DDR4 3466(O.C.)/3400(O.C.)/3333(O.C.)/3300(O.C.)/3200(O.C.)/3000(O.C.)/2800(O.C.)/2666(O.C.)/2400(O.C.)/2133(O.C.) MHz Memory
Dual Channel Memory Architecture
Supports Intel® Extreme Memory Profile (XMP)
* Hyper DIMM support is subject to the physical characteristics of individual CPUs. 
* Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists).

So yes, it does support my memory speed. If it didn't, I wouldn't have selected it when I purchased it and it certainly wouldn't support it in the BIOS.

Xsjadia

Running a Z170 motherboard, have used RAM @ both 2133 MHz and 3200 MHz. I do not see a difference.

Could also be the timings set for your XMP profile @ 3000 MHz. Even if a RAM stick can run @ 3000, it doesn't necessarily mean it will perform well at that speed.

UnFknBLievable

It is Gskill factory speed and timing for the Ram ( Ripjaw V series). I have sent Asus an E-mail also to see what they say.

Xsjadia

I understand (I never change my factory timings), but the timings that are set by the manufacturers are different for each of their mem stick products (most of the time. once the tech starts becoming ubiquitous at the same speed/level, the timings tend to become closer to the same across the board). Even though we both may have XMP profiles for 3000 MHz on our sticks, the timings could be completely different due to the manufacturer's settings. (I learned this the hard way a couple years ago when I bought what I thought was fast RAM rated to go @ 2400 MHz, but due to the timing settings at it's rated 2400 Mhz, it was actually slower, and less stable, than when I ran it at 1600 MHz in real world application)

UnFknBLievable

Did another test run in War Thunder, Iracing and Assetto Corsa with XMP enabled (performance ram timing) with Frequency at 2133mhz and ran stable.

Again - Why is Ram frequency effecting the stability of tracking performance!?!?!?!?

dougchism

I just ran several games using my new box, with 3200Mhz GSkill sticks, XMP enabled and verified in HW monitor and tracking was fine. 

dougchism

UnFknBLievable said:

Directly off the Asus website.

4 x DIMM, Max. 64GB, DDR4 3466(O.C.)/3400(O.C.)/3333(O.C.)/3300(O.C.)/3200(O.C.)/3000(O.C.)/2800(O.C.)/2666(O.C.)/2400(O.C.)/2133(O.C.) MHz Memory
Dual Channel Memory Architecture
Supports Intel® Extreme Memory Profile (XMP)
* Hyper DIMM support is subject to the physical characteristics of individual CPUs. 
* Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists).

So yes, it does support my memory speed. If it didn't, I wouldn't have selected it when I purchased it and it certainly wouldn't support it in the BIOS.

Were your sticks on the QVL list for that board? Just having the same timing speeds may not be enough. 

Also, my last ASUS motherboard, a Z77 sabertooth, could not run XMP enabled even with sticks that were on its compatibility list. XMP was pretty new back then so it was pretty common.

The MSI board I am using now is actually the first computer I have owned with no XMP issues ( yet ). 

flexy123

You may first want to do a general speed test of you ram, use Aida64 --> Cache and Memory Benchmark, to see whether there is any issues with your ram/timings. (I mean you already said your system is stable, so I am taking that you tested stability already).

If your ram with Aida is indeed FASTER than at stock (and obviously this is XMP's purpose)....YET this would introduce problems with tracking, it must be some timing issue with Oculus softare. Or that possibly some other frequency in your bios is too far off and messes with timings, but this just a guess.

Powerus

OMG I have terrible unplayable tracking and I have XMP enabled. I'll tell you if turning it off changed something.

EDIT: OK it's either worse or unchanged but certainly not better. Completely unplayable.

UnFknBLievable

I have just done some more testing.
XMP timing enabled, ram FREQUENCY is the only variable.
2133mhz - stable, flawless.
2400mhz - stable, flawless.
2700mhz - noticeable jittering but tracking was fine.
3000mhz - bad tracking, errors, warping, ect.

Can someone from oculus please give some kind of explaination? My system is 100% stable and as Flexy123 suggested, I ran Aida64 with no issues, errors or loss of performance at full factory clock speed (3000mhz). Timing is not the problem, the Frequency is affecting my tracking.

dougchism

I am not trying to sound like a jerk but I dont think you can expect Oculus to debug your motherboard/memory problems. Just run it at 2400 and be happy. 

edmg

UnFknBLievable said:

My system is 100% stable

Clearly it isn't. 

The most likely explanation, since it happens when overclocking the RAM, is that memory errors are causing the tracking to fail. The Rift cameras are presumably doing DMA to a block of RAM sixty times a second or more, and the overclocked RAM can't handle it.

VRoaaar

Run OCCT with every RAM frequency to see if your system is really stable or not. Run each test at least 30 minutes or more. See here.

elboffor

UnFknBLievable said:

I have just done some more testing.
XMP timing enabled, ram FREQUENCY is the only variable.
2133mhz - stable, flawless.
2400mhz - stable, flawless.
2700mhz - noticeable jittering but tracking was fine.
3000mhz - bad tracking, errors, warping, ect.

Can someone from oculus please give some kind of explaination? My system is 100% stable and as Flexy123 suggested, I ran Aida64 with no issues, errors or loss of performance at full factory clock speed (3000mhz). Timing is not the problem, the Frequency is affecting my tracking.

Your problem may well be timing actually. The timings generally go down as the frequency goes up.

It has always been the case in my experience.

flexy123

VRoaaar said:

Run OCCT with every RAM frequency to see if your system is really stable or not. Run each test at least 30 minutes or more. See here.

Yes I asked him that..he didn't directly answer it but I assumed he did. (He pretty confidently said his system is stable).I also would be interested to know whether he can run 30-60min  OCCT on "large" without problems. The thing is, XMP memory settings are usually not exactly hardcore overclocking settings, they are normally rather conservative.

TBH...for me it's very difficult to see how changed ram timings WHILE THE SYSTEM REALLY BEING STABLE (ie: tested with OCCT, memtest etc.) would cause such problems. The only explanation for me would be if another clock in the BIOS would be off, like PCI bus freq or something like this....or (far fetched...) that his motherboard bios does something odd it shouldn't do when changing memory speed. I am still blindly guessing his system is in reality not stable.

He needs to run OCCT at the bare minimum, and preferably also memtest (the Windows version), and spawn several instances of it and then have it run for some hours to really test. I am saying this since OOCCT/large..while being very good..doesn't test ALL memory...and the memtest that you can from CD/boot isn't as sensitive as the memtest tool that runs in Windows.

flexy123

Uhm..you didn't say what type/brand of ram it is...you only listed the board specs and what ram it supports. Would be interested what memory you have in there.

elboffor

I smell cheap ram...

edmg

TBH...for me it's very difficult to see how changed ram timings WHILE THE SYSTEM REALLY BEING STABLE (ie: tested with OCCT, memtest etc.) would cause such problems.

The Rift software is looking for flashing lights in images. The camera is doing repeated DMA, many times a second, to big blocks of RAM through the CPU's memory controller, which is only rated to 2133MHz. May not take many memory errors to confuse the software about which pixels are flashing and which aren't.

And, oddly enough, it works fine at the frequency the CPU is rated for.

e_m_d88

My PC is running with 16 gigs DDR4-3000 ram and have no problems. 

edmg

It's going to depend on a lot of things, like the precise CPU and memory you have (not just the model, but the characteristics of the specific chunk of silicon it's made from), the timings they're using, and the motherboard layout.

But it is making me wonder whether I should switch mine back to default memory timings from the XMP ones it's currently using.

lovethis

Update your Bios to F21, I have a Z170 motherboard and it's been piss poor until the latest Bios. It has had voltage problems all the way up to Bios version F21. Now my problems have gone but I'll continue to check.

UnFknBLievable

flexy123 said:

Uhm..you didn't say what type/brand of ram it is...you only listed the board specs and what ram it supports. Would be interested what memory you have in there.

G.Skill DDR4 3000mhz Ripjaw X F43000C15-8GVR.

lovethis said:

Update your Bios to F21, I have a Z170 motherboard and it's been piss poor until the latest Bios. It has had voltage problems all the way up to Bios version F21. Now my problems have gone but I'll continue to check.

Already Running the latest BIOS (v.3301) This BIOS version has also solved other issues I had with previous BIOS revisions.

edmg said:

TBH...for me it's very difficult to see how changed ram timings WHILE THE SYSTEM REALLY BEING STABLE (ie: tested with OCCT, memtest etc.) would cause such problems.

The Rift software is looking for flashing lights in images. The camera is doing repeated DMA, many times a second, to big blocks of RAM through the CPU's memory controller, which is only rated to 2133MHz. May not take many memory errors to confuse the software about which pixels are flashing and which aren't.

And, oddly enough, it works fine at the frequency the CPU is rated for.

Thank you for the only decent theory as to what could be going on.

I don't know how many times I have repeated myself on multiple posts. If my system was "unstable", I'd be having other symptons with software and I wouldn't be here trying to fix it.

Memory is currently at 2400mhz manually set.
XMP profile timing from CPU-Z
Freq - 1500Mhz
CAS - 15
RAS to CAS - 15
RAS Precharge - 15
tRAS - 35
tRC - 50
Voltage - 1.35v

I have downloaded OCCT, ran it for 30min at factory 3000mhz XMP profile. (it's late) and was fine

UnFknBLievable

flexy123 said:

Uhm..you didn't say what type/brand of ram it is...you only listed the board specs and what ram it supports. Would be interested what memory you have in there.

G.Skill DDR4 3000mhz Ripjaw X F43000C15-8GVR.

lovethis said:

Update your Bios to F21, I have a Z170 motherboard and it's been piss poor until the latest Bios. It has had voltage problems all the way up to Bios version F21. Now my problems have gone but I'll continue to check.

Already Running the latest BIOS (v.3301) This BIOS version has also solved other issues I had with previous BIOS revisions.

edmg said:

TBH...for me it's very difficult to see how changed ram timings WHILE THE SYSTEM REALLY BEING STABLE (ie: tested with OCCT, memtest etc.) would cause such problems.

The Rift software is looking for flashing lights in images. The camera is doing repeated DMA, many times a second, to big blocks of RAM through the CPU's memory controller, which is only rated to 2133MHz. May not take many memory errors to confuse the software about which pixels are flashing and which aren't.

And, oddly enough, it works fine at the frequency the CPU is rated for.

Thank you for the only decent theory as to what could be going on.

I don't know how many times I have repeated myself on multiple posts. If my system was "unstable", I'd be having other symptons with software and I wouldn't be here trying to fix it.

Memory is currently at 2400mhz manually set.
XMP profile timing from CPU-Z
Freq - 1500Mhz
CAS - 15
RAS to CAS - 15
RAS Precharge - 15
tRAS - 35
tRC - 50
Voltage - 1.35v

I have downloaded OCCT, ran it for 30min at factory 3000mhz XMP profile. (it's late) and was fine

guysery2000

UnFknBLievable, I have the exact same problem.
Asus Z170-A and tracking problems if i overclock my ram (i can notice that instantly if i run The Unspoken, with Touch tracking going super messy every couple of seconds). 
I tried 2133mhz (the frequency they are staying at now) for them to be stable, and 2666 or more, at which they started to be unstable. I also came to the conclusion that cpu overclock was not the culprit, so i decided to keep that and keep the Ram at 2133, but lowering the latencies (tightening them). So far so good.
I don't remember Ram modules' brand atm, but if this information can be helpful i will check and come back for sure.
I will definitely try to go up to 2400mhz with my Ram and see what i can accomplish with the Rift