GPU artifacts with hardware acceleration but not gaming...

[Mr.Meerkat]

Late 2022, I upgraded my Fury (with a few CU's unlocked, 3840SPs) to a Sapphire 6900XT Toxic EE. It's AIO was replaced by Alphacool's block, which apart from it being incredibly restrictive (compared to my Fury's EK block...), performs very nicely. With a gaming load or stress test (Heaven, Timespy extreme and Furmark), the GPU works just fine. No crashing, no artifacts, absolutely no oddness. Not even a driver crash. Sadly I can't say the same about hardware acceleration/compute loads however.

 

Back in 2022, I did notice that occasionally, I would get half a dozen white pixels scattered across the screen whenever I was doing something that involved browser hardware acceleration (namely YouTube). Originally thought it was just Chromium being funky so kind of disregarded it. I also did notice Capture One starting to crash once every 25th time opened, but for that, I blamed it on the Corsair 3200MHz DDR4 kit that couldn't even run at 2400MHz. Fast forward to 2023, I get Topaz AI, intending to denoise and upscale a bunch of photos from the noughties and 2010s. Unfortunately the hardware acceleration rears it's ugly head again, but this time making it unusable. Whenever I try to denoise or upscale an image, the output image would have all kind of artifacts, from purple pixels to lines to weird circles shapes, making the image unusable. Tried various drivers and whatnot to no avail but with my laptop having a 3050ti, I kind of ignored it...until two weeks ago. 

 

Friend hosted an university event and for fun, I photographed it. It was a dark venue and couldn't use flash so all the images were shot between ISO6400-12800. 900+ photos reduced to 150~ final images and with Capture One's denoising tool being useless old fashioned, I tried Topaz with the 6900XT again. Still artifacts on the output images but as it takes the 3050ti 30-40s/image with Topaz, the time saving with the 6900XT would have been substantial as it only takes 2-3s to process each image (i.e. 1.5hrs vs <10 mins). Now with new drivers (including trying AMD pro), different PSU for testing (old XFX XTS 1kW), new Micron DDR4, reinstalling the GPU block, fresh windows install, undervolting/underclocking (core only as for some reason VRAM is locked to 2000MHz min), basically all thee troubleshooting steps that exists, I could not get the artifacting to go away. 

 

As there's nothing left to do, I randomly selected 1500MHz on the core and 2200MHz on the memory...the artifacting was gone. 1500 core/stock 2000MHz mem, artifacting is there. Stock 2375 core/2200 mem, artifacting is there. After playing around, I managed to get it to 1915 core/2100 mem without it artifacting in hardware acceleration loads. As I do like 5hrs of gaming every 3 months nowadays (and it's 2560x1080p anyway), the underclock is completely fine but huh? Is this a software issue? GPU die issue? Memory issue? The underclock I can understand but why do I have to overclock the memory as well to make it not artifact during compute loads? 

 

Don't suppose anyone here has any ideas? 

 

TL;DR Sapphire 6900XT Toxic EE, completely fine in gaming and stress tests (including timespy extreme, heaven and furmark) but artifacts during H/W acceleration and compute loads. After troubleshooting with every single method under the sun, found a remedy which involves underclocking GPU core from 2375MHz to 1915MHz (not as bad as it sounds as stock 6900XT is 2015MHz) whilst also overclocking VRAM from 2000MHz to 2100MHz. If core is any higher or memory is any lower, it causes artifacts in compute loads. Anyone have any ideas? It straight up doesn't make sense to me...

 

Hey, on the brightside, with the underclock (and undervolt), it's now a 160W GPU instead of 320W under full load (and sub-50C temps!). Also, just in case someone is thinking, why 6900XT, especially the most expensive version (Toxic Extreme Edition), it was cheaper than a 6900XT nitro, cheaper than 6800XTs and was roughly the same price as 6800s back in 2022 so had no doubt in my mind to buy which card. 

[Brian McKee]

Well hardware acceleration is different from the main core obviously, so it's possible it's defective in some way. But the solution to me is the truly bizarre part, I can't think of any reason as to why that'd fix it.