Dedicated GPU (Graphics Card)

Hi I am no pc nerd , but when Zwift made my pc obsolete (its an AMD Athlon processor),
I thought I would get around the problem by putting in a dedicated GPU.
I had two kicking about,
an AMD Radeon R5 8490 HD @ 1gb
and an AMD Radeon DDR5 6950 HD @ 2 gb
To my surprise however the 1gb 8490 unit, produces a far more stable platform than the 2 gb 6950, even after upgrading the power supply to cope with the extra wattage.
Has anyone else encountered this and or know the reasoning behind this.

Are you running them at the same resolution?

my issues have stemmed from the CPU, I had thought that a better GPU was more important but it turns out my i5 just can’t keep up… perhaps it’s something similar with yours?

@Dave_ZPCMR is your man. He’ll be along soon.

What generation of I5 is it?

yes resolutions are the same, ithink the 8490 is maybe a younger GPU
One of the most annoying things , is at the initial start of a group ride , where the riders on the bikes keep disappearing and coming back, till the group strings out,but it does not happen with the lower spec 1gb card

Just be mindful that there are a couple of bugs where riders disappear that isn’t related to your GPU

I’d have to check but I was under the impression it was fairly late model

The 8490 is from July 2013. The 6950 is from December 2010.

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He was talking about the i5 age.

I was responding to this…

Stuart, the AMD is not i5 equivalent, with AMD its a Athlon or Ryzen core processor, the Athlon I have is, roughly equivalent to between an i3 / i5.
Zwift said the graphics side of the processor is no longer supported, and further so after august, in their upcoming upgrades, however they also stated that with a dedicated graphics card, it would still work fine, as I say , it is fine with the 8490, and this seems the better card than the 6950, where the latter was/is more expensive, bigger,@ 2GB ( with two fans and separate power feed) , I just cannot understand why that should be.

Hi Donald, i was replying to RC Ivany in relation to him saying he was running am i5.

The 6950 annihilates the 8490 in raw ability, despite the age difference. It’s 5-6 times as powerful.

The answer to your question depends on how you’re defining ‘more stable/better’ on the lesser card. And how you compared the two. Plus what your vsync settings are.

Zwift determines profile (graphical detail) automatically, and independently to the resolution chosen. The 6950 gets High profile, and the 8490 almost certainly gets Basic. So there’s one possible reason. Nevertheless, it doesn’t seem right.

I dont understand …vsync settings ???

By default Zwift uses vsync. A constant 30fps on a weaker setup may seem ‘better’ than repeated ups and downs between 30fps and 60fps on a stronger setup that can’t maintain 60fps. On an Nvidia card you just enable triple buffering to allow the frame rate to be anything (without tearing). I don’t know where the setting is on Radeon drivers, or whether it has the same effect. AMD graphics cards are an inferior choice for Zwift on Windows, because of the platform it runs on.