Graphics Driver Latency

[Bill Phillips]

I need to replace my existing graphics card and would like to install one with the lowest driver latency possible. According to LatencyMon my existing R7 250 graphics card driver is my highest latency driver at >0.5 ms. I have two displays, one each HDMI and VGA. The VGA monitor is flickering so I'm going to replace it with a second HDMI monitor which requires a graphics card with two HDMI interfaces. I'd like to get a graphics card with the lowest driver latency possible. Currently audio playback during mixing crackles at the highest sample buffer size available for my Focusrite Scarlett 18i8 mainly because of the plugins I use. The CPUs 12 threads hardly ever exceed 10% but the graphics card latency is >0.5 ms.

My video card is in the PCIe 2.0/3.0  x16 slot closest to my i7-6850K CPU which has 40 PCIe lanes. My existing graphics card is only x8 but the the slot it's in has 16 dedicated PCIe lanes. I understand that video performance is not important to Cakewalk's performance but driver latency is. So, I'm wondering if using a graphics card that can use all 16 lanes and operate at lower latency would reduce audio crackling during mixing. 

Any suggestions appreciated.

[chuckebaby]

Which gen 18I8 are you using ? Im using a 1st gen and have no issues with Latency (I have an I7 6700 using onboard Intel graphics).

It could be a problem with the Saffire driver. Have you tried uninstalling it and reinstalling it ? Make sure your using a USB 2.0 port if you have a 1st gen 18i8. Oh and always use the same port you used to install the drivers on.

[Jim Roseberry]

Using a higher end video card won't increase your DAW (audio) performance.

 

FWIW, We've found the latest Nvidia RTX-2xxx series video cards to suffer from high DPC Latency.

If you're trying to run heavy loads at a 64-sample ASIO buffer size or smaller, avoid RTX video cards (for the time being).

The GTX-1xxx and newest GTX-16xx series are fine.

 

The AMD Vega-64 and Radeon VII video cards have lower DPC Latency than the GTX video cards.

I've not seen Vega-64/Radeon VII with a 0dB fan mode. 

 

 

 

 

[reginaldStjohn]

I can verify that the nVidia cards tend to have higher DPC latency then the Radeon cards. I swapped my nVidia GT card out with a Radeon and the DPC latency went down quite a bit.

[Bill Phillips]

8 hours ago, Chuck E Baby said:

Which gen 18I8 are you using ? Im using a 1st gen and have no issues with Latency (I have an I7 6700 using onboard Intel graphics).

It could be a problem with the Saffire driver. Have you tried uninstalling it and reinstalling it ? Make sure your using a USB 2.0 port if you have a 1st gen 18i8. Oh and always use the same port you used to install the drivers on.

Thanks Chuck E Baby.  I upgraded to 2nd gen drivers which made significant improvement. So I think the drivers are as good as they get and LatencyMon shows them down the latency list a way, well below the DirectX video drivers which are at the top at >0.5ms.

[Bill Phillips]

5 hours ago, Jim Roseberry said:

Using a higher end video card won't increase your DAW (audio) performance.

 

FWIW, We've found the latest Nvidia RTX-2xxx series video cards to suffer from high DPC Latency.

If you're trying to run heavy loads at a 64-sample ASIO buffer size or smaller, avoid RTX video cards (for the time being).

The GTX-1xxx and newest GTX-16xx series are fine.

 

The AMD Vega-64 and Radeon VII video cards have lower DPC Latency than the GTX video cards.

I've not seen Vega-64/Radeon VII with a 0dB fan mode. 

 

 

 

 

Thanks Jim. That's a lot of useful information.  I've been focusing on DirectX driver latency, which for my R7 250 is >0.5 ms because Focusrite tech support thought it was suspiciously high.

However, I'm a little confused.  At the top of your post you mention that high end video cards won't improve DAW performance; but the AMD cards (Vega-64 & Radeon VII) with the lowest latency are both high performance gaming cards and they cost considerable more than my audio interface. Do you think using one of these would help me? On first look the Radeon VII  looks to be the top performer of the two. Also, as you point out they may be pretty noisy. 

I use the Izotope music production suite which includes three metering plugins that I like. When they're not bypassed, crackling is a lot worse. So at least some of my crackling problems seem to be associated with video processing.

Thanks again.

 

Edited April 22, 2019 by Twisted Fingers

[Jim Roseberry]

16 hours ago, Twisted Fingers said:

However, I'm a little confused.  At the top of your post you mention that high end video cards won't improve DAW performance; but the AMD cards (Vega-64 & Radeon VII) with the lowest latency are both high performance gaming cards and they cost considerable more than my audio interface. Do you think using one of these would help me? On first look the Radeon VII  looks to be the top performer of the two. Also, as you point out they may be pretty noisy. 

I use the Izotope music production suite which includes three metering plugins that I like. When they're not bypassed, crackling is a lot worse. So at least some of my crackling problems seem to be associated with video processing.

Let me clarify:

If your video card is causing DPC Latency of 500+uSec, installing a video card that doesn't increase DPC Latency (where the driver is much better behaved) would certainly solve that problem.  With low/consistent DPC Latency, you'd achieve better DAW performance.

Note that this isn't the same as the video card itself allowing you to run more audio processing.

In your case, you need the video card to essentially "get-out-of-the-way" when it comes to impeding performance (high DPC Latency).

 

I'll give you another example.

Say you're using the onboard UHD-630 graphics on a i9-9900k CPU.

The UHD-630 drivers are well behaved (don't cause high DPC Latency).

If you then wanted to upgrade to a Radeon VII (drivers are also well behaved - low/consistent DPC Latency); you'd see no increase in DAW performance vs. using the UHD-630.

 

Regarding the Izotope plugins:

Your problem with glitches is due to high DPC Latency (not from poor video performance with the plugins enabled).

IOW, Upgrading to an RTX-2080Ti (which currently suffers from high DPC Latency - but is a much faster video card), would still leave you with audio glitches.

The lower your ASIO buffer size, the more critical to have low/consistent DPC Latency.

 

If you're also working with video, what you need is a faster video card that doesn't significantly increase DPC Latency... and that's quiet when working with audio.

Right now, for many folks a good sweet-spot (price/performance) is the new GTX-1660.

When working with video, you may be surprised that there's not a huge (realtime) performance difference between using a RTX-2080ti vs. a GTX-1660.

IOW, Previewing realtime VFX like Trapcode Particular doesn't run significantly faster with the RTX-2080Ti. 

The RTX-2080Ti would help a bit more on long video Renders.

 

 

[abacab]

According to LatencyMon, I got 0.005 ms highest execution time with the Intel Graphics Kernel Mode Driver (Intel HD graphics, integrated).  It was also relatively low on the recorded DPC counts.

[Bill Phillips]

5 hours ago, Jim Roseberry said:

Let me clarify:

If your video card is causing DPC Latency of 500+uSec, installing a video card that doesn't increase DPC Latency (where the driver is much better behaved) would certainly solve that problem.  With low/consistent DPC Latency, you'd achieve better DAW performance.

Note that this isn't the same as the video card itself allowing you to run more audio processing.

In your case, you need the video card to essentially "get-out-of-the-way" when it comes to impeding performance (high DPC Latency).

...

Regarding the Izotope plugins:

Your problem with glitches is due to high DPC Latency (not from poor video performance with the plugins enabled).

...

The lower your ASIO buffer size, the more critical to have low/consistent DPC Latency.

Thanks, Jim.  All true. My video card is causing DPC Latency of 500+us and I do need for the video card to "get-out-of-the-way." And I understand that the video card can not allow me to run more audio processing and that my video performance is fine. The problem is DPC Latency with my ASIO buffer size set to the highest (1024 samples) value.

5 hours ago, Jim Roseberry said:

Say you're using the onboard UHD-630 graphics on a i9-9900k CPU.

The UHD-630 drivers are well behaved (don't cause high DPC Latency).

If you then wanted to upgrade to a Radeon VII (drivers are also well behaved - low/consistent DPC Latency); you'd see no increase in DAW performance vs. using the UHD-630.

 

Regarding the Izotope plugins:

Your problem with glitches is due to high DPC Latency (not from poor video performance with the plugins enabled).

IOW, Upgrading to an RTX-2080Ti (which currently suffers from high DPC Latency - but is a much faster video card), would still leave you with audio glitches.

The lower your ASIO buffer size, the more critical to have low/consistent DPC Latency.

 

If you're also working with video, what you need is a faster video card that doesn't significantly increase DPC Latency... and that's quiet when working with audio.

Right now, for many folks a good sweet-spot (price/performance) is the new GTX-1660.

When working with video, you may be surprised that there's not a huge (realtime) performance difference between using a RTX-2080ti vs. a GTX-1660.

IOW, Previewing realtime VFX like Trapcode Particular doesn't run significantly faster with the RTX-2080Ti. 

The RTX-2080Ti would help a bit more on long video Renders.

 

 

My ASUS X99-DELUXE II does not have onboard  graphics. It supports up to 3 video cards. I didn't want or plan to use multiple video cards but liked its other features such as USB 3.2 and Thunderbolt 3 support. I wonder if the fact that it can support 3 video cards increases DPC latency? 

Also, I don't do anything with video right now. All I do is record and mix audio. So, based on what I'm learning from you, I want a video card with modest graphics processing capability and the lowest DPC latency possible. And if possible, one that occupies a single slot. Is that out of the question given my desire for low DPC latency?

I've also read that AMD video cards have lower DPC latency times than nVidia cards. Is that "old " or "fake" news?

 

[MediaGary]

Your instinct is right in that a change of driver is necessary, but that aspect of that driver behavior pertinent to audio performance is to find a video card/driver that's "agile" in  letting go of the PCIe slot.   The video card driver of the R7 250 is possibly "hogging" the PCIe slot, but that behavior is not specifically related of the number of active lanes within that slot. 

There is an audio forum that I frequent that has good things to say about AMD RX580 cards regarding their compatibility with audio performance.  I have an Nvidia GTX 1070 card in my machine which is supposed to be less good in that respect, but it's working fine with no audio issues.  Many people have done well for audio work using the native Intel graphics functions. 

Here is a link to a long thread on the issue.  In short, there are confirmations and counter-cases, so it's nothing absolute in either direction:

[https://www.gearslutz.com/board/music-computers/1212416-dpc-latency-better-amd-graphic-cards-3-card-comparison.html ]

[Bill Phillips]

33 minutes ago, MediaGary said:

Your instinct is right in that a change of driver is necessary, but that aspect of that driver behavior pertinent to audio performance is to find a video card/driver that's "agile" in  letting go of the PCIe slot.   The video card driver of the R7 250 is possibly "hogging" the PCIe slot, but that behavior is not specifically related of the number of active lanes within that slot. 

There is an audio forum that I frequent that has good things to say about AMD RX580 cards regarding their compatibility with audio performance.  I have an Nvidia GTX 1070 card in my machine which is supposed to be less good in that respect, but it's working fine with no audio issues.  Many people have done well for audio work using the native Intel graphics functions. 

Here is a link to a long thread on the issue.  In short, there are confirmations and counter-cases, so it's nothing absolute in either direction:

[https://www.gearslutz.com/board/music-computers/1212416-dpc-latency-better-amd-graphic-cards-3-card-comparison.html ]

MediaGary, thanks. I read that article too. By "hogging" the slot do you mean over using it's assigned PCIe lanes? If yes, I don't believe that's a problem for me. My graphics card is in a PCIe 2.0/3.0 x16 slot and I believe that it is the only user and does not need to share of those 16 lanes. My PC has 40 lanes. Most of the others are shared, but not those.

There's a newer model RX590 that has a 256-bit memory interface. I wonder how it would compare (DPC latency wise) with the GTX-1660?

[Jim Roseberry]

FWIW, It's not hogging the "slot"... the driver is monopolizing CPU time (High DPC Latency).

That can cause a "hiccup" in data flow.  A typical general-purpose user would never notice say a 5ms hiccup in data flow.

For someone running a DAW at a 32-sample ASIO buffer size, that 5ms hiccup in data-flow results in a glitch (at best)...  or a transport drop-out.

At a 32-sample ASIO buffer size (44.1k), the machine has 0.75ms to process/fill the next ASIO buffer.  If it's not filled in time, you'll experience a glitch or drop-out.

 

The X99 Deluxe II doesn't blanketly have a problem with high DPC Latency (it's the video card's driver).

If you don't need much in the way of video processing, go with a GTX-1050 or one of the new GTX-1650 video cards.

 

Right now, the AMD Vega-64 and Radeon VII result in lower DPC Latency than Nvidia GTX video cards.

The difference isn't huge; GTX video cards can be effectively used when running DAW applications at small ASIO buffer sizes.

Right now, Nvidia RTX-2xxx series video cards result in high DPC Latency.  Ultimately, I'd expect this to be ironed out.

I wouldn't blanketly say that AMD always results in lower DPC Latency than Nvidia.  That's the case when comparing these video cards (at this point in time).

Several months down the road (or with different models), things could change radically.  That's the nature of computer hardware.

A brand/model that's not a particularly great performer *today*... may be tomorrow's best-in-class.

ie: Years ago, there was a time when Maxtor HDs were poor performers.  Then, a couple years down the line, they were some of the best performers.  Flash forward to the year 2006... and Maxtor was absorbed by Seagate.

 

If you're not working with video, the video card's processing capabilities are (obviously) a secondary factor.

Well-behaved drivers and low noise are more critical factors for DAW purposes.

 

 

[Bill Phillips]

Jim Roseberry, thank you very much. You've answered all my questions and I really appreciate it.

[TheMaartian]

My 'old' nVidia Gigabyte GTX 750 Ti gives a 0.14 mS DPC latency. Think I'll stick with it.

[MediaGary]

Thank you Jim  [ I promise *not* to call you Mr. Roseberry again :-)  ]  for your pithy summation.   You have prevented me from digging too deep into the weeds on this topic to develop an answer that fits my neurotic approach to technical questions.  

I was reading through this document in my non-existent 'spare' time [  https://www.mindshare.com/files/ebooks/pci express system architecture.pdf ]  In its 1038 pages, it covers all the stuff about PCIe function, but of course leaves it to the reader to infer how  an "aggressive" driver would cause citizenship problems within the overall system.   

This document may still be handy for my project to get a GC-Titan-Ridge Thunderbolt working properly in my 2010 Mac Pro. We'll see.  Okay, back to the original topic!  Thanks to all!

Edited April 25, 2019 by MediaGary
spelling typo

[Bill Phillips]

17 hours ago, John Maar said:

My 'old' nVidia Gigabyte GTX 750 Ti gives a 0.14 mS DPC latency. Think I'll stick with it.

Thanks, John. Yeah, why fix something that's not broken.

How long had LatencyMon and Cakewalk been running at the same time when you read that latency? Were you mixing?

Gigabyte GTX 750 Ti's are still available used at Newegg!

[TheMaartian]

45 minutes ago, Twisted Fingers said:

Thanks, John. Yeah, why fix something that's not broken.

How long had LatencyMon and Cakewalk been running at the same time when you read that latency? Were you mixing?

Gigabyte GTX 750 Ti's are still available used at Newegg!

Oops. Don't have my specs in my sig. Sorry.

I'm currently doing most of my work in Studio One. I was tracking, not mixing. I should try it while mixing.

Re the 750 Ti...I've got the 4GB version. Bought it when AMD stopped updating the driver my ancient (early 2012) Radeon card.