MP 5,1 (mid2010) unable to play 4k 60fps

[raist8]

So, you mean even on a clean install Mojave, with the latest clean Chrome, with good internet connection, that 4k 60FPS YouTube video still very choppy (with that CPU / GPU usage capture)?

Yes it's. I think something is wrong with hardware, I don't know what or why :/ A 4k 30fps plays super smooth, in local and on youtube, for example this:

On this video, both CPU and GPU doesn't reach half of capacity..

 

[h9826790]

Our hardware is extremely similar, shouldn't have that big difference.

However, may I know if you are running 4x8GB RAM? Are they 1066 or 1333? Even I don't think it should make that huge difference, but this is one of the potential difference.

I am now running 3x16GB 1333MHz RAM.

 

[raist8]

Yes, with a clean install same issue, also with High Sierra...

 

[raist8]

Hi!

I have 2 Ram modules 16 each at 1333

 

[h9826790]

Hi!

I have 2 Ram modules 16 each at 1333

There is a little bit difference at here (in spec). 3x16 can utilise the triple channel memory bandwidth, 2x16 only has dual channel bandwidth. However, I really doubt if this can really make the difference (performance) in this case.

 

[raist8]

Discovered the ***uking problem. Thanks to your clue: I have 2 16GB RAM modules. When I changed the RAM I put them on position 3 and 4. I change it now to 1 and 2 and video plays fine! Incredible.. Thank you so much for your help.

 

[h9826790]

Discovered the ***uking problem. Thanks to your clue: I have 2 16GB RAM modules. When I changed the RAM I put them on position 3 and 4. I change it now to 1 and 2 and video plays fine! Incredible.. Thank you so much for your help.

Oh~ you ran them at single channel flex mode. It seems the memory bandwidth really decrease too much in this case and causing the issue.

So, now we know, dual channel work. But single channel flex mode can cause issue.