AMD RX 460 runs very slow with two concurrent WUs
30 Nov 2016 11:11:36 UTC
Topic 203289
(moderation:
I am currently running Binary Radio Pulsar Search (Arecibo, GPU) 1.52 (BRP4G-Beta-opencl-ati) WUs on an AMD RX 460. When running with the default settings (2 concurrent WUs) it is taking 10 hours elapsed to process a pair of WUs. According to GPU-Z, the CPU is at 100%, but power draw and memory controller load are low, and the fan spped and GPU temps are low.
If I suspend all of the WUs so that only one runs, it takes only 50-60 mins to run (effectively 5 x faster than running 2 together). Processor load is mostly in range 70-100% (often pegged at 100%) and power draw, temperature and fan speed indicate it is doing a lot more work.
I also have another system with an R7 260x. This system runs fine with 2 concurrent WUs (elapsed time while running 2 WUs is 1 hour 50 mins). This is curious because the R7 260x and RX 460 are essentially identical from a compute point of view though the RX 460 has faster clocks.
Both systems are running Windows 10 64 bit, AMD driver version is 21.19.137.1.
Thanks
From your description it
)
From your description it appears likely that work spent on CPU jobs is crowding out the CPU support needed to run two simultaneous GPU tasks efficiently. Other than by suspending work, have you tried reducing the number of CPU tasks running?
I don't think that is the
)
I don't think that is the problem - the amount of CPU it would take to feed two tasks using half of the GPU vs 1 task using most of the GPU would not be much different. The system is an I7 4790 running at about 60% overall utilisation, so there is no shortage of available CPU resource to feed the GPU. Also, I have two other similar systems (R7 260X and RX 470) that run fine with 2 concurrent WUs on the AMD GPU.
Thanks, D
Dyeman, I had very similar
)
Dyeman,
I had very similar issues with my RX480's whereby they would run tasks fine for 10 - 15 mins before the memory controller activity dropped from a constant 60ish % to 0 -2% resulting in horrendously long runtimes.
The fix for me was to update my Intel chipset drivers!
Gav.
Greetings I had a similar
)
Greetings
I had a similar problem with Radeon/ATI 7750.
My gpu had 2GB of onboard memory and still ran over twice as slow when running 2 WA simultaneously.
I swiched back to a setting os 1.0 CPU and 1.0 GPU
(My CPU runs a bit cooler with 1 kernel idling most of the time.)
Please post on how things work out.
Happy Crunching!
Jay