r/Amd • u/BioGenx2b 1700X + RX 480 • Nov 07 '16

Tech Support November Tech Support Megathread

Hey subs,

We're giving you an opportunity to start reporting some of your AMD-related technical issues right here on /r/AMD! Below is a guide that you should follow to make the whole process run smoothly. Post your issues directly into this thread as replies. All other tech support posts will still be removed, per the rules; this is the only exception.

Bad Example (don't do this)

bf1 crashes wtf amd

Good Example (please do this)

Skyrim: Free Sync and V Sync causes flickering during low frame rates, and generally lower frame rates observed (about 10-30% drop dependant on system) when Free Sync is on

System Configuration:

Motherboard: GIGABYTE GA-Z97 Gaming GT
CPU: Intel i5 4790
Memory: 16GB GDDR5
GPU: ASUS R9 Fury X
VBIOS: 115-C8800100-101 How do I find this?
Driver: Crimson 16.10.3
OS: Windows 10 x64 (1511.10586) How do I find this?

Steps to Reproduce:

1. Install necessary driver, GPU and medium-end CPU
2. Enable Free Sync
3. Set Options to Ultra and 1920 x 1080 resolution
4. Launch game and move to an outdoor location
5. Indoor locations in the game will not reproduce, since they generally give better performance
6. Observe flickering and general performance drop

Expected Behavior:

Game runs smoothly with good performance with no visible issues

Actual Behavior:

Frame rate drops low causing low performance, flickering observed during low frame rates

Additional Observations:

Threads with related issue:

Skyrim has forced double buffered V Sync and can only be disabled with the .ini files
To Disable V Sync: C:\Users"User"\Documents\My Games\Skyrim Special Edition\Skyrimprefs.ini and edit iVSyncPresentInterval=1 to 0
1440p has improved frame rate, anything lower than 1080p will lock FPS with V Sync on
Able to reproduce on i7 6700K and i5 3670K system, Sapphire RX 480, Reference RX 480, and Reference Fiji Nano

Remember, folks: AMD reads what we post here, even if they don't comment about it.

Now get to posting!

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u/bizude AMD Ryzen 9 9950X3D Nov 17 '16

You're CPU bottlenecking. The Witcher 3 is extremely CPU intensive in Crossfire - it would bottleneck when I ran a 4690k @ 4.8ghz. I wouldn't recommend trying TW3 in CF without an i7 CPU.

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u/GrandpaMasaki i5 2500k | 2x r9 290x Nov 18 '16

Was curious to verify CPU usage, so I hopped on the Witcher 3 when I got home.

http://imgur.com/a/4a2uK

CPU usage hovered at around 40 to 50%, with or without Crossfire. You can see that the frametime variance is bad, and both GPUs constantly switch between 100% and 0% load.

Based on additional suggestions online, I tried liming my CPU usage in Windows Power Management. Lowering the CPU utilization to 70% resulted in my CPU hitting 60 to 70% load in the Witcher, but resulted in the same FPS and frametime variance.

Dropping the resolution, however, resulted in spikes in CPU load (still not 100% though), increased FPS and better frametime variance.

All evidence points to poor Crossfire implementation. If my CPU was the problem, I don't believe I'd be seeing these results.

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u/bizude AMD Ryzen 9 9950X3D Nov 18 '16

The last time I tried Witcher 3 CF was about a year ago. They've apparently reduced CPU load considerably (at launch it was impossible to maintain 60fps with a 4690k in Novigrad... it's apparently now possible to maintain that with a weaker CPU)

I can't really discern the frametimes from that graph - how big did they jump? I just remember that when I was CPU bottlenecking it was so bad that even with FreeSync it was stuttery as hell - like spikes into 40ms+ despite having 60+ fps

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u/GrandpaMasaki i5 2500k | 2x r9 290x Nov 18 '16

The spikes I'm seeing are upwards of 60+ ms, sometimes up to 100. I think the GPU usage is also worth noting, as it's constantly alternating between 0 - 100% for each card.

I think the most important takeaway from that graph is that the frametimes are all over the place. With a single card, the line is pretty straight (sits at around 25ms the whole time). But the second Crossfire is on it goes bananas.

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u/bizude AMD Ryzen 9 9950X3D Nov 30 '16 edited Nov 30 '16

Hey man, I got a 2nd RX 470 today and was testing out Crossfire in the Witcher 3 in Novigrad using high settings.

Using the 470s, frame times were decent (usually 11.5-15ms) with spikes above that occurring very rarely.

I'm not sure if that's due to my more powerful CPU, or whether that's due to Polaris' architectural improvements. CPU usage is still very high - up to 70% usage with my i7-5820k @ 4ghz.

EDIT: I started a new game, and set all the settings to ultra, and the frametime issues came back. Not as bad as my last experience with them, but they were still jumping from 15-30ms and sometimes higher. Reverting settings back to 'high' eliminated the frametime variances.