Is it possible that my GPU is the bottleneck?

Question

I've got a 4GB RX-480, not the highest range, but supposed to be a good solid mid-range card. I've had it less than a year. Now in a few games I'm finding that sometimes its 1 pct and 0.1 pct lows are in the single digits, even if the averages are in the 100's of FPS! I was thinking the bottleneck may be my CPU, which an FX-8300 8-core, which I was planning on replacing soon. But when I run the game through the MSI Afterburner, it shows that the CPU is hardly more than 50 pct loaded most of the time, but the GPU is loaded around 90-100 pct, and the framebuffer is using around 3500 MB out of 4000 MB. So it seems to me that the the GPU is the bottleneck here. I got the GPU much later than the CPU, so what do you think is going on?

Answer 1

My guess is it has something to do with the coding of the game and the CPU thread that commands the GPU to Render a Frame. Currently I'm working with a PC with a socket 1366 Xeon w3690 (same as i7-990x), 12gb of RAM, and a 4gb RX 480 as well and things just seem off with the CPU usage and framerates in certain tests and games I run.



The w3690 never really maxes out and even the highest thread rarely hits 100%. However when I transfer the RX 480 to another system that has a newer CPU like the i7-4790k or Xeon E5-1680 v2 (same as a double i7-3770k), the multi-threaded CPU usages are higher but the Framerates are also higher. I'd have to retest to see what the low are, but the lows don't seem to be significant enough to pay attention to.



About overclocking the CPU and RAM... The newer Xeon E5-1680 v2 seems to benefit from overclocking but the Xeon w3690 doesn't seem to benefit much from it. In a few newer games like FFXV I've seen an improvement by setting the memory clocks to 2133mhz or 2400mhz, but the w3690 doesn't seem to bode well with memory clock speeds past 1600mhz, whereas the E5-1680 v2 and 4790k are perfectly fine with DDR3 speeds at 2400mhz. Since you're using an FX CPU, I assume you memory clock speeds are at 1866mhz which isn't bad.



This isn't something I've been able to pinpoint either, just a problem I've observed. I heard that Rendering is commanded by a single thread but I don't know why the CPU render thread won't hang up at 100% like it's assumed that it would do. Some people have said that the Render thread isn't fixed to a particular core or thread in newer games and with Windows 10. Although I haven't tried to find a way to assign a priority to the CPU nor have I tried to change anything with the Operating System..... such as setting the priority of the game to Affinity in Task manager. Usually I use a 2nd monitor and I have the HWMonitor window open when I'm running these games and tests. I don't play games that much but I observe family members use these PC's.

Answer 2

Probably, since it is not an Nvidia card

Answer 3

have you looked at your game settings? Having everything set to Max or High will put an extra load on you GFX card.

Answer 4

the gpu is inadequate for that game. either change games or upgrade to the Rx 580

Answer 5

Either you believe your 'MSI Afterburner' tool or you don't. Have you checked the Minimum Requirements of the game you're playing? Does your video card make the cut?



The first tool I usually reach for is Window's Task Manager. Take a look at Task Manager while that game is running and see which resource is hitting near 100%. Otherwise, you already have an answer from the Afterburner tool.

Answer 6

You will not tell what the video card is connected to (monitor or monitors or 4K TV) and what resolution, by whatever cable type, or which games, so how to guess?

Or you could have temperature limitation of the system or a particular component, or the wrong driver for that video card.